warm water in cws tank and pumping out the overflow

[Expertboy]

Hi,

I have a fully pumped system with a 3 port valve and a cylinder stat and a gas central heating system, and the normal mains feed to all cold water outlets.

now the problem. I have a very full cws tank, and water coming out of the overflow pipe to outside, also the water in the cws tank is warm, which would indicate to me that the open vent from the cylinder is pumping into the cws tank.

i'm sure it's a very simple diagnosis as to what has failed for a man in the know, but unfortunately my knowledge of plumbing fault finding left me years ago.

Any help appreciated.

 

[kevplumb]

Any help appreciated.

its broke

 

[bathstyle]

Could be mains water entering your system somewhere.

Do you have a shower valve that has mains fed cold, tank fed hot?

Washing machine that has both a hot and cold fill??

Has the immersion heater been left on?

 

[Nige F]

Turn all the boiler/immersion OFF IF that "warm" water gets hot the whole 50 gallons could come down through the ceiling...This has happened and seriously injured people. Over to the gas boiler guys, but they need more info. on boiler type etc.

 

[cmother1]

What's the temp. of the water coming out of the hot taps?

Do you have an ancient immersion that's been switched on by accident maybe?

 

[Expertboy]

Ok heating and hot water turned off (thanks for that), ive also drained some 'warm' water out of the cws tank.

the boiler is a Glowworm Ultimate 60f and as previously stated its on a fully pumped system with a 3 port valve and a cylinder stat. We have no immersion heater fitted, and its deffinately warm water in the cws tank.

The plumbing has been working well and all this started this morning, i changed the ball valve thinking this was the problem but obviously not.

Anything else i can check?

 

[kevplumb]

vented system

 

[Expertboy]

What's the temp. of the water coming out of the hot taps?

Do you have an ancient immersion that's been switched on by accident maybe?

quite cool actually 39.5 degrees celcius. I believe the cylinder stat is set to around 60-65 degrees celcius

 

[Expertboy]

vented system

yes.

 

[kevplumb]

is the heating header tank higher then the cold feed tank

the "it's broke crack was a joke BTW"

 

[Expertboy]

is the heating header tank higher then the cold feed tank

Yes FE Tank is in the loft, CWS Tank is in the airing cupboard.

 

[Expertboy]

I completely forgot, we do have a pump (the proper type not a heating one) on the hot water feed that supplies the house, this is because there was an extension fitted and the hot water pressure was quite low to the extension so the plumber fitted a pump that triggers when you turn the taps on, this has been fine and been working for about 3 years.

 

[doitall]

So your back to an mixer or shower valve letting by and back feeding into the hot.
Check mixer tap/valve with mains cold, including the washing machine.

 

[Expertboy]

I have narrowed this down and i'm confident it only feeds into the cws tank when the hot water is on, does this mean it's the cylinder? or possibly the cylinder stat?

 

[bathstyle]

Could be mains water entering your system somewhere.

Do you have a shower valve that has mains fed cold, tank fed hot?

Washing machine that has both a hot and cold fill???

So your back to an mixer or shower valve letting by and back feeding into the hot.
Check mixer tap/valve with mains cold, including the washing machine.

Check these please.