Including self-containment
 #95627  by raerog
 Fri Jun 26, 2015 4:31 pm
I have one of the above in my bus, it's a great unit, does the job well. However, quite often when the pump is running with no taps open the pressure relief valve does it's job. Other times the pump will turn off as it should when it gets up to operating pressure. my boiler is around 12 years old and in the manual supplied with it there is NO mention of a PRESSURE REDUCING VALVE! However in the manual I have found online for a model 6 years younger there is one in the circuit. I have contacted 2 "service agents" and have got 2 different answers as to what is causing the problem. 1 has told me it's probably a split tank! This I find hard to believe, surely if the tank were split there would be water everywhere. We last used the bus last Sunday and today when I was in it there was still pressure in the water system. This is from the accumulator attached to the pump. This is enough to tell me that the system per se does not leak and there are no fractures, splits or otherwise anywhere.
Has anybody got any advise, solutions etc.? Personally I think my 1st course of action will be to fit a PRESSURE REDUCING VALVE into the circuit and see what happens :?
 #95629  by idex
 Fri Jun 26, 2015 5:07 pm
I think I'd be having a look at the pressure cut-out switch. I can't remember what is fitted to the Truma but if it is adjustable try screwing it down a bit. Either that or check the pressure relief valve operation. A pressure gauge on the water system should quickly give you the answer.

Good luck!
 #95630  by Teardrop
 Fri Jun 26, 2015 5:36 pm
What pressure is your water pump rated at?

 #95642  by vansvilla
 Fri Jun 26, 2015 8:38 pm
Or it could be just doing it's job, relieving excess press as the water expands when being heated.

How much water is coming out?

If not too much then I would turn the heat source and pump off, run any accumulated pressure off then pull the valve out and Check the rubber washer and seat. They can sometimes get a bit of grit on the seat.
 #97795  by raerog
 Wed Aug 05, 2015 10:48 pm
:TU Well. It's taken a while but I've finally fitted a pressure reduction valve into the system and it has done the job perfectly! No more unexpected loud noises of the relief valve blowing. Thanks for all the helpful advise! ;)
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