Crystal 2 - advice appreciated

[Geist]

I have a Crystal 2 inlet feeding the usual sink, bathroom & shower, and also the Thetford cassette,

The water flow wasn't particularly good so I removed the non-return valve fitted to the Crystal inlet, and put a larger diameter Whale non-return valve in the feed pipe next to the Crystal housing.

Bingo - the flow was much improved, and the problem was solved.

But (isn't there always a 'but'?) When I removed the water pump from the external socket I noticed a trickle of water coming from the inlet pipe.

I assumed that it must be a residue from the cartridge - but it continued to trickle out for several hours, emptying the boiler and interior pipework.

As the only way it could come out was past the non-return valve, I assumed that it must be faulty and changed it for another one.

The problem continues - and it's unlikely (but not impossible, I suppose) that both brand new whale valves are duff. The valve *is* fitted the right way around

Has anyone any other suggestions? - the water is definitely leaking out of the supply inlet - the same way it went in, but in reverse, and very slowly.

All connections are tight, no leaks inside the van, no spluttering or signs of air once the system has been filled and run - just the annoying discharge of water once the pump has been removed.

Your thoughts appreciated

 

[gary]

It would seem that pressure built up in the hot water tank is being used to push water back out of the Crystal inlet, this then suggests the 'other' non-return valve in the cold water inlet to the heater is faulty.

I don't know how the Whale valve works but unless sprung loaded it will need to be mounted vertically for it to work correctly.

If all else fails, there should be a 'blanking' plug supplied with the Crystal 2 and you can also buy this separately, that's bound to fix the problem!

 

[Geist]

Gary, many thanks for your help.

The Whale NRV is a spring loaded device that is inserted into the feed pipe - a larger bore version of the NRV contained in the Crystal housing (which, as I said, I removed)

after reading various tales of woe about the Crystal housing and it's enthusiasm for cracking, I checked carefully and the water *is* coming out of the inlet pipe, not from the filter housing.

So, it can only be the NRV. I take your point about the increased pressure of the hot water - but the leaking continues for hours, presumably long after the water in the boiler has cooled down.

I didn't get the blanking plug supplied with the assembly (what else would one expect from Wandahome caravans?) but it sounds like the ideal solution. Still, things like this bug me (being a very anal sort of person and I'd like to get to the bottom of it for my own satisfaction at least.

I wish I didn't care tuppence about whether things work properly or not - then, I was indifferent and careless enough, I could get a job with Wandahome

Thanks again.

 

[lessirrocc]

Hi we have also had this problem with water leaking back out of the water inlet,it was a piece of grit had blocked the spring which is behind the Cristal inlet that is part of a one way valve .if you pull the pipe away from behind the inlet you will see the spring just push it out give it a clean and pop it back in and it should be sorted.

 

[Geist]

Hi Les,

I'll check the valve - although, not the Crystal one as I removed that in order to increase the flow rate, using a whale nrv as an in-line replacement.

I'm suspecting the Whale valve - not least because I bought two of them at .79p each from a dealer who had a large box full of them, all unpackaged

Seconds?, faulty? - hard to say, but the retail price seems to be about 4 quid - so for less than 25% of the official price perhaps you get less than 25% of the official performance

Main thing is that it's not coming from the filter assembly (or leaking in side the van, which would have been a real pain)

I'll probably have to cough up full price for a sealed packaged valve - that's what you get for being a cheapskate

 

[gary]

I was actually thinking the extra pressure was used to create a 'syphon' and once created would drain the hot water tank and anything else until the syphon was broken.

 

[Geist]

Gary wrote: "I was actually thinking the extra pressure was used to create a 'syphon' and once created would drain the hot water tank and anything else until the syphon was broken."

Surely, if the nrv was sealing the inlet hose correctly, the pressure would only serve to force the valve even more tightly cosed?

I expect that Truma have incorporated a safety valve on the boiler - but this isn't a matter of dangerous excess pressure, just of water traveling back down the 'inflow' pipe and out of the Crystal assembly when the pump is removed.

As said, this continues slowly for several hours, even after the water has cooled down. Rather than pressure, I'm inclined to think that it's just gravity at work, draining all the interior pipes, shower, boiler etc (the outlet being pretty well the lowest pint of the system.

If the nrv *was* doing it's job properly, this (presumably) just couldn't happen?

Still, looking on the bright side - no frost damage from forgetting to drain down the system