CWST Overflowing problem

[andrewstokes87]

Hi,

I have been called to a customers property as they had an overflowing cwst in the loft, the overflow for this and the feed and expansion tank are seperate and terminate at different locations. The ball valve was constantly dripping so I presumed this was the problem and have replaced this. I have now recieved a message to return to the property tomorrow as the tank is still overflowing. I am guessing the hot water is venting into the tank but how can I prove this without actually seeing this and what could be causing this?

Thanks

 

[mikegas]

are they both the same height?

 

[andrewstokes87]

It was the cwst the heating tank is installed in a different location and the overflow pipe terminates in a different part of the property. I wouldnt like to say about the height as they are in different locations and I did not check this as I did not think that would cause a problem?

 

[jase158]

Hi,

I have been called to a customers property as they had an overflowing cwst in the loft, the overflow for this and the feed and expansion tank are seperate and terminate at different locations. The ball valve was constantly dripping so I presumed this was the problem and have replaced this. I have now recieved a message to return to the property tomorrow as the tank is still overflowing. I am guessing the hot water is venting into the tank but how can I prove this without actually seeing this and what could be causing this?

Thanks

had this before
reason for this could be...

1.cylinder thermostat
2. pinhole leak in coil
3. vent pipe not high enough above tank (debatable wether this actually causes it)

I think that is all possible reasons,

 

[mikegas]

Also mixer taps can Pass

 

[jase158]

Also mixer taps can Pass

yeah, amount of times I have connected cold to mixer tap, tested it and forgot to turn completely to cold only, gives a drip to the hot pipe which isnt connected yet. makes you wonder what happens when they go wrong.

 

[andrewstokes87]

Is there a test which I can do for the cylinder stat or the pinhole leak in the coil? Sorry if I sound so dumb but I haven't got a mass amount of experience when it comes to maintenance

 

[jase158]

http://www.ukplumbersforums.co.uk/plumbing-forum/576-header-tank-overflowing-warm-water.html

 

[SimonJohns]

Isolate the float valves
Wait to see if level in cwsc rises and if fande lowers

Is the check you can do

 

[jase158]

I cant remember if there is test for cylinder stat, but cost of these, is worth replacing before suggesting replacement of cylinder.

when is it happening, if when hot water is on only then more then likely it is the stat, if all the time, more likely a leak from cold/ central heating.