430 - Water-heater Calorifier Failure

Print Page | Close Window

Water-heater Calorifier Failure

Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 430
Forum Description: 430 Hints and Tips
URL: https://www.myhanse.com/forum_posts.asp?TID=14860
Printed Date: 27 March 2026 at 03:40
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com

Topic: Water-heater Calorifier Failure

Posted By: Dogscout
Subject: Water-heater Calorifier Failure
Date Posted: 12 October 2024 at 19:37

Well today while in the marina, I turned on the electrical heating element for the water heater and took a nice shower. Afterwards I noticed that the water pump was cycling on and off every few seconds. I looked around for leaks under sinks and then found that the plastic, engine cooling expansion tank had water spraying out of the top. I shut off the electric power to the water system pump and the spraying water slowed.

It appears to me that the engine coolant loop in the Isotemp water heater has a hole and that house water pressure is flowing back into the engine.

I cut the hoses such that the coolant from the engine will now go straight return back to the engine. The hoses from the Isotemp water heater are now joined with a union. Water pump back on and the pump is normal. I expect that there is likely coolant in my hot water pipes so I'll flush that.

So; can the coolant loop in the Isotemp water heater be repaired or replaced? Is there another failure that would cause what I have seen? At this point I am planning on leaving the system as is until I reach somewhere it is easier to buy a replacement.

Any other thoughts are appreciated.

-------------
Adventure awaits

Replies:

Posted By: Jojo
Date Posted: 13 October 2024 at 14:10

My concern is if coolant can or has find a way in to the fresh water system

Then a major issue is that most coolant is harmful and you can’t be sure that it is not contaminated

Then a big clean of the pipes is required before you can use it

-------------
3 Cabin, Hanse 342, Deep draft, Tiller version.

Posted By: Wild
Date Posted: 19 October 2024 at 08:20

IMO In your case The easy way to clean the pressured watersysteem is :close one side of the enginecoil at the boiler off and connect the other directly to the wall water supply. Open at the taps on the boat at rinse for quite a while.

The watertanks will not be contaminated because of the waterpressure pomp is always running while tapping hot water.

-------------
Wild and Wet
Belgium
545e#268