Hi Arnei,

You can always add a y-piece and run a 60 mm hose to your cold forecabin. This will be the longest hose in your system and normally you do not get enough airflow into the forn cabin. Even insulating the hose does not have a significant effect.

One of my projects for the winter is to install a small laptop ventilator inside the forecabin's outlet.

Norse King is a 2008 470e and we have a single 5000 heater. Ours has a 60mm outlet in both rear cabins and heads, one in the saloon and one in the Master cabin, where nothing but apprehension comes out !

After the saloon take off the system is reduced to 60mm.

Again I've spoken to many people including the Webasto team who are helpful here in the UK.  NK is kept in Cowes, Isle of Wight.

I've a sneaking suspicion that part of the ducting that heads to the master cabin has been partially squashed.  Mine tends to turn itself off as it overheats and therefore nothing gets warm and I'll explain this later.

Despite some reservations from the Webasto team, this is what I'm proposing to do this winter.

Replace the main run from heater to master cabin with insulated (sleeved) 90mm duct, change the 60mm outlet to a 90mm of course. Insulate all other runs.  Fit a variable speed fan in line to assist the Webasto fan in drawing the warm air forward.  Variable speed as I can adjust the amount of air (heat) forward.

Listening to ducting Engineers and assuming I've understood correctly, the square area of the duct influences greatly the volume of air that can pass through, hence remove the 60mm to a 90mm forward of the saloon outlet.  It is here I will fit the on line fan, with the variable control at the chart table.  By drawing the air away from the heater unit, it shouldn't over heat and turn off.

The Webasto guys feel that the electric fan will cease with the heat, well that's a start, some heat would be good !

I'll keep you posted on how it goes and how successful it is, alternatively keep an eye on the blogsite.

As you can see from the photo's the 90mm duct on our 2008 boat came with an inter-liner which has come away from the foil duct and created blockages.

  

                 Heater end                                          Y junction end

It appears that the further away from the heat source the inner-liner is not as bad, but this is speculative.  I'm going to fit the insulation sock to the 60mm duct that serves the two rear cabins, the liners don't appear to have detached from the main body but I may as well replace the duct as it's easier to replace with the sock already on rather than try to feed the sock along the duct.

I'll then replace the 90mm to the next two Y junctions, at the saloon heads & the saloon.  This is where I intend to fit the in line variable speed fan, but I'll see how much air flow I now get from the heater itself at this point before making that decision.

The issues I have are that there's nothing but hope that comes out of the master cabin vent and likewise the en-suite shower.  Secondly the unit it self shuts down as it appears to overheat only after a short period of running.  I've replaced the burner and spoke to the manufactures, suppliers & fitters as to gain any help I can, I also spoke to a very helpful chap regarding the ducts.

On Norse King, after the en-suite take off the duct reduces from 90 to 60mm and feeds the master cabin duct at the foot of the bed.  The duct man, suggested that the volume of air or gas that can pass through a duct greatly increases with an increase in cross sectional square area. I'm sure there's an equation on the internet that will prove the case. (Kn=0.066/Pd for air at 20C).  If I can ease the back pressure on the heater unit by increasing the volume, then hopefully the unit will not overheat.  So what if I install an in line fan, downstream of the saloon vent take off, that will enable me to draw the heated air away from the unit and push it towards the master cabin.  A variable speed switch will enable me to control the amount.

I'm not after trying to create a hair drier, after all, mines thin enough as it is these days and a simple shake of the head tends to do the trick.

The Webasto men suggested that this fan will struggle with the heat and pack up, but weren't aware where it is to be installed within the system.

None of the Webasto guys I've spoken to over the years have ever mentioned this liner within the duct that I found, nor its potential to cause a partial blockage.  Clearly this causes back pressure on the heater unit which cuts out as it is unable to reduce the heat from within it.  I'm going to work my way through the boat replacing this lined duct with new together with the insulation blanket and when I reach the Y junction under the chart table make a decision as to whether I feel there's enough air flow to omit the fan or not.

What mustn't be forgotten is that all the time I have a free and open end, air will flow out of it more easily causing the other outlets to appear not to work.  It is only once the system is contained will their be some pressure that will enable the air to pass through the vents.  A euphemism is that of an electric circuit, it has potential which can be easily diverted to earth if you touch the wrong wire.

A stationary fan will create pressure, but enable the two rear cabin, saloon heads and saloon vents to flow.  The saloon vent is of the type that cannot be closed.  Hopefully by closing the two rear cabin vent and increasing the speed of the fan I can draw more heat forward.

That's my thoughts ! 

What year of manufacture was yours ?

I have no air flow out of the vent in the master cabin nor the en-suite.  Ours is the Air-Top 5000ST I believe.

Today I ran it and measured the air temperature and the velocity within the open ended pipe in the rear cabin.  It reached 102.7C and 8.5 m/s.  I left it running and returned some hours later to find it had turned off again with two flashing indicating a fault with the burner !  However the saloon by then was toasty.  I shut the system down waited for a while before trying to fire it up again, which it didn't want to do.  I checked for an amperage increase in the boats system but this didn't change, an indication that it just shuts down completely and locks out for a while.

I understand that boats of 45' + now come with two heater units, they've realised that one unit doesn't do it.  So your correct, one serves the master cabin and it's en-suite if that's the layout chosen and one serves the rear cabins, saloon & saloon heads.

My thoughts are to provide assistance to the single unit we have by introducing an in line fan, to help draw the heat/air forward.  What I need to happen is for the unit to run without cutting out, so there may be an underlying fault with the unit.  Once I can get it to run consistently without cutting out, then I can continue to replace the ducting and keep taking measurements of the velocity & temperature at the outlets.

What's disconcerting is the lack of input (for now) Webasto is making regarding their product.  I'll give them every opportunity to assist me in getting it to run as intended.  I'll not take any prisoners if they fail to show professionalism and get it working as it should.

I'm sure there's a simple answer and may be we don't use our boats enough to get to the bottom of some of our issues.  I understand the laws of unintended consequences, Hanse may have appointed Webasto as they do other manufacturers to supply equipment to their models.  It's a new field and therefore not fully understood at the time of release, but you'd think that development doesn't stop.  The manufacturers Webasto or Eberspatcher ought to be monitoring their systems to ensure future product development, rather than be short sighted with past sales made.

I live in the UK, and so the climate is such that it needs a gentle hand to make it more bearable to sail during certain times of the year.  Lining the cabin with all the pillows we have and sleeping under two duvets is a discussion to have, but the experience is not so enjoyable.

We're blessed with beautiful boats, even if not all the equipment is up to expectation.  It is up to us to bring them down a peg or two and pull them in line.  If they're not prepared to assist, then we need to tell the industry how crap they are !

Fair winds.

I've replaced the length of duct from the heater to the first Y junction in the rear cabin (port side, same side as the unit), with new and insulated it, it has a free discharge and not connected to the downstream duct. I've run the heater with the dial (thermostat) at 3'o'clock, it goes through its starting cycle ok and runs with 102.6C and 8.5m/s velocity for a couple of hours then shuts down, with the resultant 2 flashing of the arrow.

If the thermostat cut in then I'd expect the heater to 'back off' not shut down or am I wrong in my assumptions ?

When this happens I can, after a pause, turn the dial off for a couple of seconds and have just the fan running only.  This I did until no more warm air came from the heater.  I can then fire up the unit once more and it'll run again.

I've run it at 3'0'clock again, then turned the thermostat down (anticlockwise) so the arrow points to 12'o'clock.  The fan does what I expect and the fan reduces speed (and another assumption is that the fuel pump probably delivers less by slowing down too), but then the amps drop off and the unit shuts down again.

Yesterday, I reset it at around 10'0'clock, so it was on with no flashing lights, and left it overnight.  Last nights ambient temperature was around 3C and whilst I do have two electric heaters, they will only provide a background heat and raise it another 7C internally.  Today I'll go and check to see if it has run over night, or with luck is still running.

Once I can get the thing to run without hesitation, then I'll connect the ducting down stream, which I'm looking to replace with new together with the insulating blanket.

I've sent various e-mails to the manufacturer here in the UK, with the various scenarios to date and hopefully they will come back after their Christmas break and have some helpful comments.  I am looking to replace the dial thermostat with the modern digital version as this will enable it to be programmed to come on.  This modification would instantly remove any possibility of the old device causing an issue.

Has anyone replaced the ducting retrospectively and if so does it have to be re-routed adjacent to the heads rather than follow the existing route beneath ?

When I close accidentally the aft cabin outlet the heater will switch off after 20 - 30 mins.

Which all makes sense.

Boats of 40' + are too big for a single diesel fired heater system, which is why new builds have two, one serves the forecabin only.

Also what you say is similar in that the units have an overheating sensor which triggers if air flow is restricted causing a high back pressure and not allowing heat to move away from the unit.  The units themselves are not that different in design, simple & basic.

This is why my thoughts of fitting an in line variable speed fan, which pull the heated air away from the unit and push it towards the fore cabin (master cabin), should work.  I'm of the belief that providing I'm not trying to super heat the compartments, I should be able to regulate the heat throughout by adjusting the thermostat (unit) and the variable speed fan in unison to at least get something other than anticipation out of the vent at the front.

I'll continue to work it out, all comments are appreciated.  It's only by understanding what other people have gone through that a bigger picture can be provided and solutions can be made.

That would be a very expensive overkill solution IMHO. 

I fitted an Eberspacher Hydronic system in High Time. This has a 5KW rating but heats water rather than air so the heat can be easily distributed to where it is needed without losing much heat en route. 

Rather than radiators (which would not look good on a sailing yacht) I used 4 small matrix heaters - one in each sleeping cabin and 2 in the saloon. The fan on each of these can be individually controlled with 2 speeds and off, which makes the system very flexible. After an hour the forepeak can easily achieve 21C when it is freezing outside.

My only disappointment with the system is that it is a bit noisy when all the fans are on high!

I would think about a small control electronic, maybe with a raspberry pi pc with seperate temp sensors. 

On the other hand it will be difficult to adjust the general Temp and the vans speed.

BR Thomas

Complicated electronics don't like damp environments and these are boats when all said and done.

The Webasto has managed to run all night last night, a Wha Hoo moment as I stood on the hard looking up listening to the singing of the exhaust.  So today I opted to connect the un-insulated downstream section of duct which goes beneath the saloon heads and finishes under the navigation table.  I turned the dial (thermostat) up slightly and continued to polish the hull before the rain drifted in.

With light fading and one more section complete, I sat on the floor with a cup of tea, a torch and my Kestrel 3000 and pondered as to how I'm going to feed the larger 90mm duct forward to the master cabin, as the existing is 60mm and attached to the hull with cable ties.  I decided that I will have to 'drill' circular inspection holes (150mm dia)  in the base of the storage space under the seats, so I can not only get to these cable ties, but also get two arms in to feed the new duct through, the next obstacle being the master cabin en-suite of course.

With the torch I could see the cable ties under the seats but I could also see that at sometime during manufacture someone had stepped on the duct flattening it !  This clearly is one more reason why nothing but hope & anticipation came out of the front.  Is the puzzle slowly unravelling  ?

With the Kestrel, I could measure accurately the velocity from the new free end and it reached 2.0m/s and the temperature was a cosy 45.0C.  There is of course another take off (Y) under the saloon heads feeding the heads themselves.  I like the idea of this being nice and warm acting as a drying room, but I mustn't get ahead of myself.

So for now at the new setting, I've left it running, hopefully it has settled down.  The fuel has dropped from 235l when I started trying to run it by 15l, suggesting that there is an issue.  Last night it had only dropped 2l.

I'll keep you posted.

(http://www.ybw.com/forums/archive/index.php/t-354020.html)

I am not sure whether this point needs to be taken into consideration as well.  I note that the forum article you refer to is from 2013.  Over the last few years, the diesel you buy for road vehicles has bio diesel in it, whilst I know that about 3-4 years ago, our marina was particular to point out that its diesel was not bio-diesel, as it is generally accepted that this is more susceptible to diesel-bug. 

From numerous articles, I have seen, the conclusion seems to be that running the heaters on low for a long time leads to carbon build-up, so the advice seems to be you either run it in on-off mode, or make sure you run it at high after a period of running on low.

If your heater does suffer from a build up of carbon then another trick I have read about (with supporting evidence) is to run the heater on high for several hours burning pure paraffin (kerosene), rather than the normal diesel (gasoil). This burns off the carbon build up, apparently. The 'supporting evidence' included before and after photos and seemed genuine (on the YBW/PBO Forum a couple of years ago).

Correct governments have been encouraging bio additives in to the fuel and some suppliers add more than others.  Also in that forum it does say that the heaters do need to be run hot to prevent the build up of carbon.

Today is a misty/foggy one, so mild.  When I went to the boat the heater had stopped working but no flashing.  I was hopeful that the thermostat had done its thing and so I turned it up.  It went through the start procedure then baulked and gave me two flashing.  I checked the in line filter as I remember it had a slight air bubble, this had very little fuel in it, so I removed it and run it without the filter for now.

I let it cool down and then fired it up again on the hotter setting and set to polishing the push & pull rails. It had been running for a while and I'd been up the bow end and was working at the stern, when a tale tale blue cloud of smoke came from the exhaust and it shut down !  I'll get my self some high grade diesel and lower the pump feed in to it and get the unit to run and see if fuel is the issue.  If it is then I'll put a second tank dedicated to the heater unit.

On Monday I''ll have a chat with Webasto and see what their opinion is as to whether they're working on a new type of burner that can cope with the lower grade fuels !

Roger - I think the forum discusses the running of paraffin too.  I may buy a few litres of that too ! 

Today the UK Webasto guys returned my e-mail and the content of the discussion was very interesting.  C02 could be the answer to the problems.  I fitted a new burner a while back, but knew nothing about C02 levels apart from those that you install an alarm for in a household situation.  It would appear that if I take my unit down to a local fitter/supplier, he can set it up on his rig, run it and like your car, the exhaust gas analyser will tell him all sorts about how the unit is performing and can make adjustments to get it to the optimum burn.

This means that the marina fuel which is ultra low sulphur road fuel, that this "standard" fuel now has up to 7% FAME ( bio-diesel).  So by adjusting the units C02 it can run as intended and efficiently as possible.

So what I've done is to link the unit back to the boats tank & see if the absorption of water in our tank may be the cause of the burn outs. If the unit struggles then my next move is to buy some fresh marine fuel

 (low sulphur 7% bio + dye) 'standard' fuel in my spare fuel can & see what happens.

The mild winter is not helping to a degree as the thermostat appears to be doing its job & putting the unit in idle till the temp drops during the night. Not complaining the system appears to work.

I learnt that the oil fired heater pick up within the main tank is about a 1/3rd of the way up, at least enabling you to at least still have fuel to move the boat under engine if needs be rather than be out of juice, but warm whilst waiting for the coast guard for a tow !

Mine too is horizontal which the manual 8.6.3 - 8.6.4 suggests is ok and having watched both transitions from marina fuel to paraffin and then to forecourt fuel the pump appears perfectly happy with even when there is air in the system.  It just passes through.

Now I've linked the pump back to the yachts fuel tank, it struggles to fire up again, so I'wondering if the moisture content in my diesel is causing the unit to struggle to burn.  Going back to what the manufacturer & a supplier said, if the CO2 was set absolutely correctly, this may allow this fuel to burn.  Also I'm sure I'm not the only one but at winter we top up our tanks to prevent that air gap that could encourage condensation build up, but we probably use no more than 50 - 60 litres in a season.  So there's a residue of old fuel not forgetting of course a dousing of de-bug chemical.

So the plan tomorrow is to go to a local supplier I don't usually use (used heavily by ribs & speed boats) fill the 10l can up again and see if it will run constantly on that, if not go back a stage and run forecourt (car) fuel through it again so I can get it to run consistently.

I will take it off and take it to the supplier to whom I've been talking and set it up on his rig and watch the process of setting the CO2 level.  If I still can't get it to run on the fuel in the yacht tank, my suspicion of high moisture content in the diesel may be true.  I then have two option :-

Yes on the 470 on that fateful trip down from Scotland (when the window fell out), We ran out of fuel just as we pulled in on the fuel pontoon, the right place to do so.  However when we handed NK over to have the deck windows removed & replaced, the Webasto didn't work, this was as we'd put air in to the pick up (so we were told) and also informed that the pick up is about 2/3rds down from the top.

Today Friday, I picked up some fresh marine diesel, but the unit struggled to run beyond 14 minutes.  I then ran more paraffin through it to clear any build up carbon that may have occurred and switched back, leaving it running at 1845, see if its running tomorrow !

My thoughts so far on this issue is that our yachts hold a fair amount of marine fuel, ours is 240l.  During the season we probably use on average 50l (we haven't used the Webasto as it never worked properly), which means come winter to prevent build up of moisture within the tank it's topped up.  So there's at least 190l of old diesel that contains a bio content known to be highly susceptible to moisture that appears to cause our Webasto issues with trying to burn it, road diesel (no red dye or anti-bug mix), it runs on, hopefully, the fresh marine diesel it'll run on.

So if the C02 setting is slightly out causing an over fuelling it will stutter and flame out, if its the other way then I assume it'll be too lean causing the gauze to burn up and the unit to stop.  So I'll get the unit on a bench and gas analysed and reset.  With luck it'll burn hot enough to overcome the moisture content.  If that's not the case then I'll retro fit another tank dedicated to the unit only, at least the turn over of fuel will prevent moisture build up.

Today (Saturday) it was sunny in Cowes this morning, so I wanted to finish of the last panel of polishing on the starboard side.  The Webasto was still running on fresh marine diesel and at 1345 I switched it back to my tank of old diesel.  This heater has nearly been running for a week now, paraffin, forecourt fuel, fresh marine and back to my tank.  I checked it this evening its 1 point shy of 18oC in the saloon but more importantly it's still running ! 217 litres in the tank.  When I left it there was 44.50C and 2.5m/s from the saloon vent, the unit was on standby and I expect as the temperature falls tonight it will increase its rate to keep up with that of the thermostat.

Think I'll continue to let it run burning fuel for a while, then shut it down & try to start it from cold a day or so later.  Meanwhile I'll continue to replace & insulate the ducting replacing the front section to the master cabin from 60mm to 90mm.

See what happens.

Congratulations to Armel & Alex for a fascinating race.

Tried to cold start but it refused to fire up, switched to the remaining fresh fuel and removed the filter, but again no go.  I looked back at the log and we took the tank down to 80 litres before refuelling, so a third of a tank of old fuel only remained.

I spoke with my local Webasto specialist, from whom I've bought new burners, exhaust & ducting etc., from and we've decided that I'll take it off and we'll have a look at the burner, then check the C02 level, back in-situ and remove to adjust, it must be that it is not burning efficiently enough to burn off any slight combination of impurity, be that higher moisture content, dye or/& diesel-bug.

I've checked my fuse today (30amp) and it sits high & dry cable tied to the bank of four batteries, so is clean and dry, with a fresh layer of oil from my fingers.  The unit refused again today to start on fresh marine diesel, so I'll take it off and examine the burner with the my friendly supplier, then get it running so the CO2 levels can be checked.

With the electronic issues I've had following the window falling out years ago, I'm wary of not spending another £1200 on replacement batteries just yet.  So I'll allow the shore power battery charger, of which I replaced, to float (trickle) charge the batteries for a while then I turn it off and allow the AIS to draw charge.  if I'm working on board I fire up the VHF, radio at minimum and sometimes run the instruments just to keep a current going through them on occasions.

I've also tried to fire up the heater in both battery and shore power mode without luck recently.

Webasto now sell an electronic thermostat which has a digital clock, I've also heard rumoured that there's one that will link to your phone.  This is to enable you to programme a start time enabling the boat to have warmed up before getting up.  I purposely didn't say awake, as I'm sure the noise of such things will wake you up anyway.  Alternatively, you can start it remotely.  So it should start on 12.5v and there's plenty of amps in our batteries after all we carry enough, I've linked the 3 service batteries with the 4 large use items using an isolator switch, this means when sailing & I'm not anchoring or using the bow thruster I have all 7 prolonging the need to start the engine to recharge.

So I doubt it was ever in Webasto's mind that the boat had to be plugged in or the engine running before it'll fires up properly, that defeats the object.

Thanks for the response, good to know people are out there.

Time is almost immaterial, it must have been a couple of years ago, if not three, however because it never delivered any useful heat and shut down constantly, we never used it, relying on electric heaters if we opted to call in to a marina.  For those weekends when at anchor, two duvets and a wall lined with pillows did the trick.  Although I always managed to draw the short straw when making the first cup of tea !

Once I've taken the unit off again, I'll take it to my friendly supplier/fitter and we'll strip it down and see what state the burner is in.  Bearing in mind I've run paraffin through it to burn off any carbon build up.  He reckons that if there is excessive moisture in the fuel, rust spots will appear.

It does seem logical that having opened up the unit to see what's happening inside, I may as well replace both the burner and the glow plug, it's a false economy not to.

A lot of the problems seem to stem from the build, in that ducting has been trodden on, or the old liner has come away from within causing a blockage.  Like the rest of Europe we're gripped with the cold, so I can't continue to deep clean the hull & polish and the Webasto is a job I've had on my books to sort.  I'm sure once sorted the thought of having a drying room in the saloon heads and cabins kept at a constant temperature will mean that early outings will be looked forward to rather than a challenge of resilience.

You're quite right about the unit, I too took it apart when replacing the burner and found it quite basic, the electronics must be the clever bit.

I take you point regarding diesel quality, but I hadn't realised previous articles on the forum and was experimenting to gain knowledge.  After all this talk about the introduction of bio-fuels it was an avenue that may have influenced it and was fairly simple to check.

How often to you change the burner ?

I took the inline filter off as there's no way in knowing whether this has become blocked, another reason to look in to the tank to see where the pick up line actually is, third up or  at invert level of the tank as I think David has suggested.

Fortunately I've worked closely with my friendly technician, so am not expecting rocket scientist fees !

I'm currently recovering from the result of an instant weight loss programme which I couldn't get to grips with.  So I stuck my left index finger back on after it came off worse between a bench circular saw and a piece of wood !

Lack of concentration, the grain of the wood catching the blade differently or what, I should've been more careful !

L ck of c nc ntra ion, t e gra n of t e wo d ca chin g t e bla e diffe ntly or wh t, I sho ld' e been mo e careful.

It wouldn't have been the same !

Here's another question aimed at you as a 'constant' user of the Webasto system.  Can you put figures to the amount of fuel you burn, weekly, monthly or anything helpful ?

Our 470 has a 240l tank so assume everyone else is the same.  Do you top up 100l every fortnight or what ?

So 'normal' use is in the morning to take the chill off, then in the evening when you get back.  Clearly the Christmas break (and mild weather) has probably increased its use and this picture in time suggests that 40 litres every three weeks.

That suggests that the fuel rate mine burns is probably on par with yours.

I'll take it off this week, finger willing and take it to the chap for an inspection, see how the burners fares.  Then reassemble it and check the C02 setting and go from there.

My concern is that my heater failed to run & kept cutting out, it would appear from Johan's experience that the burner does need replacing every three years or so depending on use.  I thought that my fuel consumption may be high leading me   to believe I'm burning too rich, bearing in mind I built three rally cars in my youth, so have an understanding with combustion engines & processes, or fuel could be contaminated give similar results.

I'd be well happy if I could have the confidence that not only will the unit run on demand, but it would run consistently, also that the hot air would appear in the Master Cabin.

I've found build & design issues with the duct work so hopefully I'm on top of that.

I don't understand your calculation. 10kw/L Diesel would mean 0,5l / h from my understanding.

Am I wrong?

BR Thomas

Simon,

No offence taken & all input welcome, this is what makes this forum so useful.

With these devices being relatively simple & not rocket science, there can not be many reasons why it wont run properly. For me, like Sherlock Homes, it's a matter of elimination, I hope. Still I'm no good at catching fish, they can out smart me so I'm not that clever after all !

I took the fuel inspection cover off & with the red light of my night torch looked for the fuel pick up. It appeared to turn & go down at an angle, I could see the weld along the bottom joint, but not the pick up pipe.  There's still over 200lts in the tank, so once more fuel is used I'll take another look.

In the meantime I'm having a litre from the tank tested but it looked pretty good to me, if a visual inspection is any reference.

Today Sunday (5th), I'll take the burner out, I've ordered a new one. Once running again shall get the exhaust C02 tested.

For those that haven't seen the inside of a Webasto unit, here it is with the top off exposing the burner unit.  The two yellow wires feed the glow plug; you can see the thin oil feed pipe and the bar across holds it all in place as the burn takes place on the other side.

Electronic side off looking down

into the unit

Burner 'cup' looking

carbonised too rich ?

Above is the burner unit looking at the business side, the glow plug fed by the yellow wires and the mesh which is almost entirely covered in carbon.  My thoughts are, that if I saw an exhaust pipe in this state then it would be burning too richly i.e. too much fuel, so not burning efficiently.  It was mentioned previously that the pump doesn't speed up, well it does, you can here the ticking increase during start up and then settle down to a consistent 'heart' rate, the rate depending on what you've set the thermostat to.

However the C02 emission determines how the burn process is going on inside and can only be adjusted with a lap top, I think and I may have this wrong to low and it's burning too rich (my issue I think) and to high and its too lean, not enough fuel.  The lap top adjustment must adjust the only thing left that enables the burn process to occur in any situation and that is the supply of air.  Cut the air off and it'll go out, supply the correct amount with the correct amount of fuel and it'll burn nicely, ask any firefighter.

My unit is an Airtop 5000 ST from around 2007 period, which looks slightly different from yours.

The electronic side of this basic unit has, like modern cars a socket in which a lap top/PC can be plugged in to and I'm sure like any diagnostic check on ECU's of modern vehicles, but not so complicated, it'll state what the air/fuel mix ratio has been set to.  With the exhaust fumes analysed and a C02 level known, the ration can be reset and thus the burn efficiency changed.

It may be a tad cosy in the stern locker as I will want to see for myself what's occurring !

Below is a pic of the unit undergoing a gentle clean so as not to damage the gauze.  For those that are unaware as to how these work, the diesel is pumped through the gauze to atomise it, the ignition being provided by the glow plug (the third necessity of the triangle of fire).

Glow plug attached to yellow wires

fits in the slot at the top

I reassembled the unit and put it back on board.  It fired up ok and ran, so I switched it back to the boats tanks, clearly air had got in the system during the switch, so the unit stopped but fired back up, so I left it running.  However I checked it around 18 hours later and it had stopped again, two lights flashing.  This afternoon (Wednesday 15th) I fired it up again and left it running, just need my man to check the C02 levels and plug his lap top in !

Johan,

I turned the thermostat and the unit set about it's wind up functions, however two flashing was the result.  I'll grab my friendly man by the scruff of the neck and get the system running so he can stick his gas analyser up the exhaust and his lap top to the system, then hopefully some answers can come from it.

This is where ideas developed of installing variable speed fan under the saloon, as we were getting nothing from the vent in the master bedroom.  Conversations and thoughts lead me to believe that as the hot air wasn't being removed/drawn quick enough it was overheating and turning itself off.  A ducting expert tells me that the increased square area between a 60mm & a 90mm duct increases the volume which can pass through significantly.

I've been meaning to add these insulation socks and increase the size of the duct to the master cabin in the hope that some heat would find its way forward, but always run out of time.  This year I had the socks and length of duct ready, so when it was too cold to clean & polish the hull, I set to and found issues within the Webasto system.

I just can't find a solution yet to consistency with the unit.

Yesterday the system wound down when I arrived to check it, pleased that it had still been running the 14hrs or so.  I vented the cabins to get fresh air in there and allow the temperature to drop and got on with other jobs.  When the sun dropped the thermostat, with it's shining green arrow, still hadn't fired up the unit, so I increased it (clockwise) and off went the rapid flicker as expected during the start process.  Yet it couldn't fire up again and two flashing lit up the darkened saloon, I went home !

I'll make a point of grabbing my friendly dealer next week and armed with his lap top and exhaust analyser get something out of him.

I see your unit is the Airtop 5000D model is that correct - where ours is the 5000ST, different burners apparently.

See what the day brings

The running of paraffin in this model and probably others will leave an oily layer on the inside of the burner and affect the flame, causing it to extinguish.  European legislation required the outside temperature not to exceed 130C and so this unit had a revised temperature sensor fitted, which caused the brain of the unit to try to lower the burn temperature by reducing fuel.  Unfortunately, the air fan is connected directly to the burn fan, so as the burn fan slowed, the air fan also slowed, the sensor realising that the temperature wasn't reducing slowed the fuel rate further, until it gets to a point where combustion can no longer exist, two flashing lights!  It was unable to get itself out of the downward spiral.

Also, the chips inside these things keep a running record of whats gone on before and thanks to the specialist, I was able to see the history of all the faults that had occurred during its life.  It also had a break down of how long it ran at 100% and down to flame out in four stages.  Ideally, these units want to run at 50%, enabling the carbon to be burnt off, the cause of the problems.  My units profile was back to front.

Newer units are able to control the air fan separately from the burn fan, so run the burn leaner raising the temperature preventing carbon build up, it also enables them to run on a wider range of quality fuels.

I thank the specialist in Swanick, Uk for giving me the time to explain.  Would the fitting of an in line fan help?  Well, yes it probably would have as it would've prevented overheat, but the fan would have suffered from the heat itself and required eventual replacement.

Will I replace it with a brand new unit and all the kit that comes with it, or will we put up with doubling the duvet & putting additional pillows against the walls.  Well jury's out on this one for the time being, but at least I have my answers.

The Airtop 5000ST like all the units only has the one fan motor, but the air fan, the one with blades on the outside is directly connected to the burn fan on the inside which is a flat disk. I was tempted at first to fit an in line fan as the duct passes beneath the chart table under the floor on the 470.  When I started to replace the ducting I found two issues, the first was that the inner liner had come away (see earlier photo's) and the second appeared to have what appeared to be a single footprint so likely to have been trodden on during boat build, under the saloon.  So I had hoped that this was the reason air or more importantly air with heat, didn't reach the master cabin, alas no.

When the sensor on the outside of the heater realises it's approaching the magic 120C, it reduces the fuel input and the burn fan speed.  Unfortunately, the fans being connected via the one shaft means that the air fan slows and cannot remove the hot air quick enough to stop the sensor repeating itself, which it continues to do so until the unit cuts out, two flashing.

The in line fan could assist in drawing this hot air away from the unit, keeping it running, but the experts think that this fan will eventually suffer from the heat and cause the bearing to cease.

We've not had the heater since we've owned the boat 6years, so double duvets and pillows next to the walls have sufficed in the past, it's going to make the tea you notice it.  I had decided this year I would get to the bottom of it and I have, will I buy a replacement - not sure only once, early one season, can I say it would've been very nice to have had one, but then it was -8C in the cockpit.

 

Guys - for what is worth, my Webasto Heater 5000 on my 400 gave me similar issues, would not start up first time, and would run inconsistently and shut down. The problem was traced to a faulty fuel pump. If you listen carefully at start up the pump should make a 'clicking noise'  - this will slow down once the heater has fired up . Listen for the clicking , if your not getting it all the time , the pump is on its way out .

Also there should be an in line fuel filter between the tank and the pump for this to run correctly - the factory did not install this - hence my fuel pump failure .

now my heater works perfectly.

 

 

 

On the later 470's they came with two heaters one serving the master cabin only and the other the rear cabins & saloon.  The length of duct from out the back of the unit to the master cabin is too long for the ST, how long do you think your longest duct run is?

I've installed the 90mm duct all the way to the Master Cabin now and it is all covered in the thermal sock, the only section under the saloon heads, that I can't get to hasn't but I'm happy if the heads get a bit warmer as this doubles as the wet room for coats & salopettes.  Although talking to the specialist guy he's suggested a method of removing this section too, so I'll look at it and decide whether to replace or not.

The constantly open outlet that was in the saloon is now the larger one in the Master Cabin, so I can shut the saloon off at night and send, in theory, warm air on to the front in the morning.

However, despite finishing the insulated ducting off shortly, do I buy a new unit to replace my unworkable one, or, as I've been without it working for 6 years, just leave it for any subsequent owner to fit at a later date.

Before I think about whether to sort this out once and for all, or just sort out the ducting properly and any new potential owners, should we God forbid, come to sell our pride & joy, can install a new unit for themselves. I'm going to test my original plan & fit an in line variable speed fan under the chart table & see if my theory works. I have also moved the heat sensor that causes most of the ST issues away from the main body.

It's all reconnected, the fans electrics have been wired in temporarily for now & I'll soon fire it up and see how long it or even if it works !

I did run the Webasto with the electric fan I fitted, but alas despite removing the heat sensor from the Airtop to hang off the side, the same issue ensued, flame out failure and four flashes of the warning light. NK will be back on the hard from December and I'll complete what I started with regards to the ducting. The purchase and fitting of a new Webasto can wait.

Clearly anyone who has a single Airtop ST5000 to serve their 470 should be having similar issues.

bad to here that the Season was less sailing...

I am one of the Owners who have a single Webasto installed. I have no issue like you and my WEebasto is running without any Problem. I still believe that you don't have a 90mm Hose from the beginning to the end. I guess there is a Reduction in the Diameter in shorter distance to the Heater which brings the Problems to you....

Only my Opinion....

Well some good news on the heater front.

I've managed to strike a deal with the supplier I extensively spoke with in Swanick up the Hamble and bought myself a new Evo 55.  I'm currently carefully taking the wiring if the old system out before running the new.  Idea here is that I can run the old one in the garage to see if it is the fact that the long ducting and overheating that shut it down.  If it runs without issues then a friend of mine will fit it to his 28' yacht.

I'm sleeving as much of the heater duct as I can get at with the insulation sock and running 90mm right to the Master Cabin.  This has meant that I had to enlarge the hole between the Master Cabin heads and the saloon, which, I did last year but got fed up.

So fingers crossed I'll get more than just hope out of the heater vent in the Master Cabin!

good to hear that you find a Way to upgrade your Heater! I installed a 90mm insulated Hose forward to the Master Cabin! It's not easy, even when you going under the Head (already no Space) but the only Way! Good Luck...

BR Björn

good to hear!! After you have finished the Job, you'll feel like a King!!😉👍

BR