Black tank problems / replacement
Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 385/388
Forum Description: 385/388 Hints, Tips and News
URL: https://www.myhanse.com/forum_posts.asp?TID=10675
Printed Date: 27 March 2026 at 03:41
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Topic: Black tank problems / replacement
Posted By: Speedwell
Subject: Black tank problems / replacement
Date Posted: 19 March 2018 at 02:17
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I have had an ongoing problem with black tank blockage onboard my 2013 Hanse 385. I am thinking of replacing the black tank and or fitting a diverter valve straight to sea. Has anyone any advise on this? Does the tank come out of the wall space behind the shelved cover? There is a steel band holding the tank in with no apparent way of removal? Do I have to break the wall out? Thanks. ------------- Simon |
Replies:
Posted By: 415 Singapore
Date Posted: 19 March 2018 at 07:46
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Hi we had a few problems with this in our first year, but after some messy research found that the problem was barnacles growing just inside the through hull fitting, it only takes a couple of barnacles and some loo paper and the tank soon backs up. We don't flush loo paper anymore and clean the through hull fitting fairly regularly and haven't had any problems since then. I would be surprised if the problem is with your tank as there isn't anything to go wrong inside it, the only other thing that can go wrong is the air intake filter can become blocked, but that can be cleaned easily. We also fitted a Gobius external tank monitor so we can check if the levels are rising. I can assure you that my other brilliant idea which was to put a high pressure hose into the deck waste fitting doesn't work! Even with the small tank that Hanse insist on fitting there is quite enough in there to cover you head to foot!  ------------- Paul - Night Train - 415 #136 |
Posted By: Speedwell
Date Posted: 19 March 2018 at 08:49
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Hi Paul, Thanks for this. Ours seems to clear easily with a trip round the side in the tender and a plunger. I also had a similar brilliant idea using the tender pump to pressure up the tank which didn't end well either (much to the amusement of my crew! Do you clean the through hull fitting whilst in the water? What tool / method do you use? How far up the pipe are the barnacles usually? Thanks for your help on this. Best regards Simon ------------- Simon |
Posted By: 415 Singapore
Date Posted: 19 March 2018 at 09:15
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Hi, glad to hear other people have brilliant ideas too! What can possibly go wrong? By pressurising your tank, you may well have blocked the air intake, so it might be worth checking that. Yes you can reach the through hull from a low dinghy, I just use a big flat bladed screw driver that you can use the side of to gently scrape round the fitting, the barnacles don't seem to stick particularly strongly and are usually just inside the fitting so come off quite easily. I would suggest staying upstream of the outlet as if there is a blockage........ Good luck ------------- Paul - Night Train - 415 #136 |
Posted By: Persse
Date Posted: 19 March 2018 at 10:57
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Toilet paper blocks the system very easily. If at a marina finger you can reach under water with a hose going and unblock it easily enough. I banned toilet paper going into the system a log time ago and have not had a repeat blockage. ( fold up the paper and put in plastic bag for disposal ashore) Phil O
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Posted By: Snow White
Date Posted: 19 March 2018 at 12:42
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And in case of an electric toilet... What about ? ------------- Have a good Day. |
Posted By: 415 Singapore
Date Posted: 19 March 2018 at 13:32
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Hi Snow White, as they say in SE Asia, same same! No toilet paper and keep the through hull clean ------------- Paul - Night Train - 415 #136 |
Posted By: Wild
Date Posted: 20 March 2018 at 09:49
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Hè Simon, It is easy to take the tanks out. First you take all the tubes off than simply lift the tank out of the steel band. There is no other fixation of the tank. Normaly there is enough space to to take out. We do this job every year to clean the tanks. The most common problems of blocking are: 1 )the intake has a very reduced connection and the tube who is going up inside the tank get blocked. It is not easy to clean this tube from the outside because of the reduced incoming connection. I have drilled a inspection hole with a removable flange in the topside of the tank just opposite the tube and made a SS tool same dia als the inside dia of the tube to scrab the dirt out. 2) the outlet connection has the same reduced dia and get easy blocked. You can clean this from the outside. 3) check al the tubes for blocking. In the Med the temp , the salt in the water and the fact that we live 6 months in the summer on board make this job necessary. ------------- Wild and Wet Belgium 545e#268 |