450: Water heater over pressure valve

[Darksyde]

Hi ,

i had a problem yesterday that my overpressure valve from my water heater drained water and did not stop.
i switched off the water pressure pump.

after that i played with the valve. everything seems to be good.

when we went to bed i switched of the water heater.
at 6 o clock in the morning the over pressure valve opened again.

any ideas ?


Marcus

[Pizzazz]

These valves need to be replaced every 8-10 years. It is $40. Just replace.

[Ulstue]

If the Waterpressure pump did not stop and if you have this Jabsco Combi
https://nauticashop.ch/de/jabsco/par...behaelter-12-v

- it has a "Relay" at the side, that could be defekt. This relay is not neccesary, you can pull it out and connect the wires direct to the pressure switch.

[Ulstue]

Did you solve the problem?

[Darksyde]

Not yet.

it happens not regularly. Maybe the Watermaker is doing a overpressure to the
Watertanks and the pump cannot handle this.

Just trying to find the reason why this happens

can anybody who has a DUO 100 tell we how it is connected to the water tanks

Maybe the Problem is the ventilation of the tanks

M

[gstent]

Hi Marcus - I have just developed the same problem - intermittent release of water from the pressure relief valve - did you resolve?
Cheers George

[Darksyde]

I found the problem

It is not the valve


It is def. the Relay of the water Pump as Ulstue said

Just bridge it or replace the relay

you can test it.....

if your hear that the water pump is not stopping knock with a screwdriver or something
on the black relay at the pump

The pump will immediately stop

Best

Marcus

[gstent]

Thanks Marcus - I will have to explore a bit more deeply when these short discharges occur - my water pump does switch off. I was thinking the valve was the problem. Cheers.

[sailorchic34]

Odds are what is happening is the water in the water heater is expanding and there is no where for the expanded (heated) water to go. So the relief pops.

The fix for this is to install an expansion tank/accumulator in the cold water line to the water heater.

If you have a variable speed water pump add a check valve in the cold water line ahead of the expansion tank and water heater. If you have a on/off water pump leave the check valve out..

The $30 2 gallon expansion tanks at the big box stores work better then the $90 marine accumulator.

[tuskie]

While you are playing with the water heater plumbing, check that an isolation valve is fitted.

Our L400 had no way of turning off (isolating) the fresh water feed to the water heater. If the water heater decides to leak, the only way to stop the flow is to turn off the boat's whole fresh water system. A cheap valve fitted to the fresh water intake of the water heater is an easy fix. Just a thought.