Posted 14 April 2009 - 11:58 PM
I have a 2005 Sterling europa with a Truma/Crstal maxi pump - i'm almost certin it is the Mk 2 - it has no filter
the problem is out truma ultrastore water heater has begum slowly leaking hot water back into the aquaroll water tank, draining the ultrastore of hot water over a period of a few hours
I have changed the non return valve that is situated just before the drain down plug on the cold water inlet pipe, however, the draining takes place slowly and lacking sufficient pressure to activate the non return valve.
Is there another non return valve that is attached to the back of the housing/connector where the water pump connects to the inlet on the caravan?
if i remove the pump from the aquarill I can suck and blow (no don't laugh) air through the pump and aussume the pump itself does not contain any non return valve
The taps are all microswitched so don't beleive i have any pressure problem
as i said, any help here would be of great assistance
Posted 15 April 2009 - 11:52 AM
Posted 15 April 2009 - 12:18 PM
Leaving the ultrastore on should have no adverse effects, that is what they are designed to do,,,,be left on whilst on site.
Posted 15 April 2009 - 12:33 PM
are you sure , truma told us they should be turned off when not in use , evenmore so at night time just for this reason
Posted 15 April 2009 - 01:44 PM
i have already replaced the non return valve on the cold water feed to the ultrastore - this is the one immediately before the drain cock. However, i tested both this and the old valve and they do not prevent a return feed if the flow pressure is very low - you can test this by blowing gently through the valve against the flow direction. This is what is happening, i.e. hot water from the ultrastore is flowing very gently back down the cold water feed pipe, through the non return valve and back down into the aquaroll, presumably due to the expansion of the hot water
I was wondering whehter the inside connector of the pump housing, i.e. the part that connects the flexible cold water piping to the housing itself, contains some kind of non return valve.
I've also had another thought - should the pump fit into the housing so as to create an airtight fit? If air is getting into the pump pipework this may allow the syphoning of the water - just a thought
Also, anyone any idea as to whether the bottom of the pump, i.e. the bit that is submerged in the water contains a non return valve?
all the best
Posted 16 April 2009 - 08:24 PM
The pump itself does not have a NRV in it.
Posted 17 April 2009 - 12:05 AM
i reckon it must be the nrv at the back of the housing - i'm going to remove the housing and see if i can clean it out; failing that try a new housing
Posted 27 August 2009 - 08:41 AM
There are no signs of leakage within the caravan.
I've put buckets under the drain outlet and the overflow pipe outlet and these have both stayed empty and dry so I'm not losing water from there.
Just incase it was the non return valve on the crystal 2 filter housing that was letting water back into the aquaroll I've been and bought and fitted a new in line non return valve between the filter housing and the Truma ultrastore. This still hasn't solved the problem.
I've not got a clue what to do next and have completely run out of ideas.
I could take off the connections on the Truma ultrastore and replace them but cannot see the point as the new inline NRV would stop water getting back anyway even if the Ultrastore connections were sticking.
Possibly replace the pump, it's a carver maxi 3 circa 2003 I guess, while not brilliant pressure wise would replacing the pump actually make any difference becausse once the wtaer is through the new NRV and into the Utrastore it shouldn't get back again anyway - should it?
The only observation I have made is that once I've filled the Ultrastore up if I then removee the pump and put it into a dry bucket (pump still attached to caravan, then I am getting water back into the bucket. I'm assuming that this is water that is draining back from the filter housing and pump pipe though not sure, nor can I understand how water from the Truma Ultrastore would find its way back through at least 2 if not 3 NRVs which are now in line.
Sorry for the long post but I'm flummoxed. If anybody has managed to sort this problem out please let me know or tell me whether a new pump could be the answer. Don't want to shell out £40 for a new pump if I don't need to.