water problem

Good Evening, Would someone be able to point me in the right direction re a problem.  I have looked at lots of posts re changing the PRV on a carver cascade (on a 1998 Symphony), I suspect this is what I will need to do but before I go down that route I thought it best to check first as I am far from mechanically minded.  I have both hot and cold running water but when pump is on water leaks out of the drain plug and it is there with some force as it rushes out if you unscrew the plug.  I see there are PRV and non return valves.  The PRV is I gather the one in top left corner.  Given my problem which of the two is likely to be a fault (or both) or is it something else?  Where is the non return one?  Any assistance gratefully received.  Thank-you.

It's been a while since I took one apart, but you're right, the pressure valve is top left. The non-return valve is integral with the bottom hose spigot assembly. Mine became stuck shut and I had to remove and replace it. IIRC it was around a tenner at the time - but that was more than ten years ago now!

If water leaks at the lower drain plug, that suggests that the O ring on the plug needs replacing, or the plug itself is split (this can happen and can result in an almost invisible split across the centre - mine did it, possibly due to frost exposure before I owned it). The water system is pressurised after the pump has been on, so if you remove the plug, water will rush out with some force - that's normal, even if the pump is no longer switched on.

I doubt it's the PRV as that would tend to leak out at the top.

I agree with Mojo re the o ring. Whatever you do , do not attempt to remove the PRV just to inspect it - it will break and you will then have to drill it out without damaging thread. So try a new o ring first.

I do wish people would not use terms like PRV, it means I have to start pondering about all the things it could mean.
However - to get back to the subject matter, if it isn't the O ring, then it could be the pressure relief valve leaking and dribbling down the front of the heater until it gets to the drain plug where it drips off and appears like its the drain plug causing the leak.
This happened to me and it means that the pressure relief valve is probably cracked and needs replacing.

Frank

Hi

-mojo- wrote:If water leaks at the lower drain plug, that suggests that the O ring on the plug needs replacing, or the plug itself is split

Yes, I normally change the O ring every year, even so I have to do the plug up worryingly tightly (for a plastic thread), I’ve never broken it though -yet!

As for the suspected faulty PRV - I assume the quarter turn device (top left) is actually closed properly.

Brod

If you remove the outer cover four screws if I remember correctly you will be able to see where the leak is.

If you have to remove and replace the pressure relief valve a box spanner is the best tool to use.

David

Thanks very much for all this, the O ring didn't look too bad but I have replaced it anyway.  Will more closely examine the plug for hairline cracks and will attempt to take off the cover to double check if I can see other leaks.  I have no intention of messing about with the pressure relief valve (sorry for use of PRV!) if I can help it, I have read too many accounts of the hassle of getting the thing out.  Reassuring to know the pressure of water is normal, it was quite a force so I feared the worst.  Re the reference to the quarter turn device, excuse my ignorance, is that the small circular end of the pressure relief valve that fits a hole in the cover?  If so is it obvious whether it is open or closed?  At the moment the screwdriver slot in it is horizontal.

Thanks again.

Further to post above I got cowl off and discovered that although from outside it looked like plug was fully in and you couldn't turn it without force, in fact it was a few mm out rendering the O ring completely useless, no wonder it was leaking.  Repeated screwing and unscrewing has got it in firmly in.  Pressure relief valve appears dry.  Fingers crossed that is all it is. 
Re the quarter turn device which I now assume is the vacuum release to assist draining (?) (have never used it), it does look decidedly loose.  It juggles when touched and I suspect that if I tried to quarter turn it, it would break.  Perhaps the pressure relief valve may have to be changed after all.  I will see how I get on.

Meantime, would the unit have originally had a rubber seal between the cowl and the frame?  Seems to be crying out for one.  

Thanks again.

If it is loose, then it is in the normal 'off' position. If it is tight, then it is holding the valve off its seat - to bleed air out.
I've found that having the valve open when filling up from empty helps to reduce airlocks in the system.

No seal between the cowl and the rest of the heater - there is nothing for it to seal,

Where abouts in Shetland are you? we visited a couple of times and loved it.

Frank

Ok thanks Frank, that all makes a bit more sense now, I will leave it to dry out and try water again tomorrow, but hopefully no leak.  I hesitate to say it but taps etc. do seem to be working much better now - famous last words.

We live in Sandwick, about half way between Lerwick and Sumburgh.  Have been here 23 years now. 

I see your details say you have / had a Symphony?  Do you still have it?

Robert

sandlodge wrote:Ok thanks Frank, that all makes a bit more sense now, I will leave it to dry out and try water again tomorrow, but hopefully no leak.  I hesitate to say it but taps etc. do seem to be working much better now - famous last words.

Fingers crossed  

We live in Sandwick, about half way between Lerwick and Sumburgh.  Have been here 23 years now. 

We will have passed through when we wanted to visit  Mousa Broch. We never got there as it was very, very foggy - both times we tried, I think we must have been jinxed.

I see your details say you have / had a Symphony?  Do you still have it?

Robert

Yes! had it since 2003, will never part with it - too many memories.

Frank

We live by the pier where you get the boat across to Mousa.  Probably my favourite place in Shetland (but I am biased), hopefully going across on Saturday weather permitting.  You will have to come to Shetland and try again!

We love our Symphony although up till now have really not had much chance to use it - trying to put that right.  There is just something about them, well made and well-designed, even though mine is 20 years old I still think the simplicity of the design hasn't been bettered.

Regards

sandlodge wrote:We live by the pier where you get the boat across to Mousa.  Probably my favourite place in Shetland (but I am biased), hopefully going across on Saturday weather permitting.  You will have to come to Shetland and try again!

I've probably stood outside your house then!   We had a look at the old hand rowed ferry <?> in the boathouse near the jetty but as I said, never got across to see the broch. I have a thing about brochs - there's something mysterious about them, the one at Clickimin is very interesting - more so than it looks from a distance.

We love our Symphony although up till now have really not had much chance to use it - trying to put that right.  There is just something about them, well made and well-designed, even though mine is 20 years old I still think the simplicity of the design hasn't been bettered.

Regards

Mine's a bit older, and I agree with what you say. When I read of the problems some people on here have with their new all singing, all dancing vans, I'm glad mine is so comparatively simple.

Frank

Glad to report that all seems ok now, no leaks and both hot and cold water running.  Hope it stays that way.
Thanks for all the advice.