Cold Water Stroage Tank Mystery

[mikejhughes]

Last November we had been away for a week and we came home to find half the bedroom ceiling on the floor due to water damage. On inspection - the cold water storage tank had overflowed. Luckily we are insured for this and someone came out and changed the fitting - new ball cock and valve etc - so job seemed done. Two weeks later just when I was going to start repairing the ceiling - same thing again.

I also have British Gas cover for plumbing - so called them out - They replaced everything again - lowered the ball cock action to way below the overflow pipe and off they went. The same thing has happened twice since - and both times British Gas have been called to sort.

It has been weeks since anything happened - but was away for a week again last week and the same thing has happened again - I had turned both hot water and central heating off before going away in case it was that causing a problem..

Any thoughts - I had hoped British Gas could have sorted - they seem to be scratching their heads over this?

Thanks

 

[PlumbBobBob]

could the overflow be blocked?

 

[Sean Mckinney]

Its probably a daft idea but with the ball valve etc being new and therefore presumably perfect I am wondering if there is debris (if that is possible) in the supply that could be being flushed into the ball cock's valve and preventing it sealing. I ask because at times brown water does come out of the kitchen tap here.

Alternatively could there be any animals getting into the attic and for some peculiar reason jammimg the ball cock down. The cold water tank here is covered to stop dust etc getting into the water but such would also serve to prevent strange animals getting at the ball cock. As mentioned by the previous poster is the overflow blocked?

Are you sure it is an overflow rather than a leak?

 

[mikejhughes]

Thanks - I have caught the water coming out of the overflow in last couple of weeks - so that seems to be fine.

Thanks

I will check if there is any debris - Water is very clear though.

Thanks

 

[justlead1]

Mike, Ask them to increase the size of the overflow pipe to say 32 mm . It should be fitted below the height of ball valve. This will allow time to identify reason without getting flooded. Good Luck

 

[joe brown]

it seems the cistern is filling to quick for the overflow pipe to discharge it, That seems to be the problem, Get your levels correct and possibly fit a larger overflow

 

[mikejhughes]

Thanks Guys - I'll give the larger pipe a go.

Mike

 

[Blackcatgas]

Have you got a mixer shower/one of those bath taps with a shower hose on??, it sounds like mains water is back filling the cylinder and tank up through the feed pipe on the bottom of the tank.
coil on the cylinder could be pinholed and the heating tank is higher than the cold water tank and is also back filling the tank.

 

[Bernie2]

Could be a few things. The overflow upgrade is a good idea, in I think Scotland that is what is normally done. They have 22mm as a first warning pipe then a 32mm as a main overflow pipe.

You can also get overflow problems on unsupported plastic tanks causing the ball valve to vibrate.

You can also get problems with water pressure picking up during the night.

The same if the ball valve arm is to short or the float not big enough or the ballvalve orifice and seating are the wrong size for the pressure.

You can get problems with leaking cross linkages somewhere in the system.

You can get problems as said if there is a leaking coil and the central heating header tank is higher than the main storage tank.

You can get problems off the cross connection on washing machines, dish washers and so on.

Its a case of looking at all the options if its not obvious.

 

[migoplumber]

are you sure its the cwsc ?
sounds like lots of replacement parts so far - have you proved 100% its the problem ?

 

[Blackcatgas]

Could be a few things. The overflow upgrade is a good idea, in I think Scotland that is what is normally done. They have 22mm as a first warning pipe then a 32mm as a main overflow pipe.

You can also get overflow problems on unsupported plastic tanks causing the ball valve to vibrate. Normaly acompanied by a loud groaning noise, would it cause the ballvalve to pass enough water to overcome a 22mm overflow? unlikely In this case.

You can also get problems with water pressure picking up during the night.
True, but its a new ball valve and they will take 15 ish bar?

The same if the ball valve arm is to short or the float not big enough or the ballvalve orifice and seating are the wrong size for the pressure.
Again, its a new ball valve so unlikely in this case.

You can get problems with leaking cross linkages somewhere in the system.
This is where my money is.
You can get problems as said if there is a leaking coil and the central heating header tank is higher than the main storage tank.
Would probably be filling up the tank constantly rather than ocasionaly.

You can get problems off the cross connection on washing machines, dish washers and so on.
Where my money is as above.

Its a case of looking at all the options if its not obvious.

Nice post Bernie as per all your posts, Iam not trying to contradict anything youve just said, merely trying to narrow down the possibilitys for the original poster.

 

[westflo]

Mike, Ask them to increase the size of the overflow pipe to say 32 mm . It should be fitted below the height of ball valve. This will allow time to identify reason without getting flooded. Good Luck

That is right. Getting a much bigger size of overflow pipe can fix this problem. Also, you can lower the pressure of water going to your heater and cooler.

 

[AWheating]

do you have any thermo blending/mixing valves? most blending valves are not designed to work with a pressure difference between the hot and cold of more than 1 bar. i have known this to cause domestic tank to overflow.

do you have a leak in your roof above your tank?

 

[Dotty]

Chaps, this thread's a year old!

 

[BLOD]

Had a similar problem the other day - customer was filling the kids paddling pool from a hose pipe
attached to the kitchen mixer tap.
cwsc was overflowing like niagra, but the paddling pool was nice & warm

 

[AWheating]

Chaps, this thread's a year old!

he may still have a problem? LOL