HELP! Tank keeps filling up!

[delboy19]

Hi

My immersion hot water tank keeps filling up with water after the stop cock has closed off the refill supply!

After suspecting it was a washer needing replaced in the valve body, I disconnected the refill supply and left to get a new washer. When I returned, the tank had refilled and was flowing into the overflow pipe. The only location that the water could have been coming from was the pipe which is internal in the tank (see pic 2).

Would there be a backfill of cold water from somewhere else apart from refill? This would make sense why the water this morning at 7 was warm instead of hot after having been on from 4-5 (it is usually piping hot).

I live in a Maisonnette flat with the tank in the spare bedroom upstairs. The outlet for the overflow is above the front door (floor level with upstairs). The cold water tank is on the roof of the flats (above bedroom).

I previously had problems with the hot water pressure in the upstairs not being strong enough so there is a pump installed in the bathroom.

I have 2 mixer taps, one downstairs in the kitchen and one in the bath.

Below is a couple of pics of my tank.

In the first pic you can see the overflow (top right pipe). The bottom pipe is connected to the overflow pipe running down past it. I suspect the middle pipe is my feed to the hot water taps?

Any help or advice is greatly appreciated!

Thanks!

Untitled

• delboy19
• 1 Jun 2010
• 1

Untitled

• delboy19
• 1 Jun 2010
• 1

 

[seco services]

more likely one of the mixer taps is passing cold mains to the hot and backfilling the cylinder.

 

[TicklyT]

It is certainly not unknown for water to flow from cold to hot supplies via mixer taps or shower mixers, hence the usual requirement for check valves on the mixer supplies.

 

[delboy19]

Thanks for the replies!

A couple of questions then.

How can I fix this?

Is it straightforward?

Thanks again.

 

[seco services]

change the mixer or fit check valves to the supply.
trouble with check valves they can restrict the flow from the hot.

 

[delboy19]

Are check valves simple to fit? I presume I would need to fit one to both mixer taps and the shower?

As I've already got a pump for the hot water upstairs, would the flow be restricted with that in use?

Thanks

 

[seco services]

what shower have you got ?

 

[delboy19]

It's not an electric one and we don't have gas CH. It's just fed from the water tank via the pump. A mixer type?

 

[seco services]

so the shower hot is pumped and the cold is gravity ?

 

[delboy19]

Yes.

 

[seco services]

the kitchen cold should be mains fed i would suspect that mixer first.

 

[delboy19]

Thanks Seco

I'll try that tomorrow then. I take it I can get the valve from B&Q? Will it be simple enough to fit?

 

[seco services]

isolate water, cut the pipe, fit valve, turn on the water.

 

[delboy19]

Thanks

 

[delboy19]

I've realised that I failed to ask an obvious question! What pipe do I fit the valve to? The cold pipe downstairs next to the kitchen sink?

Thanks!

p.s. in relation to an earlier reply re reducing hot water flow, the hot water flow downstairs is pretty poor.