Cold water tank in the attic overflowing

[GGg]

Hi All,

Looking for some advice. The tank in the attic has been trickling out of the overflow for a few weeks now.

I have an open vented system with a hot water pump (Stuart Turner monsoon twin 3) fitted.

Have already changed the valve and float in the attic. Set it very low but water is above the float. Tested it fine know it shuts off the feed that way.

Also changed the thermostat on hot water cylinder, so tank isn’t getting too hot and venting over.

I do have a shower fitted with mains cold and tank fed hot. (Plumber at the time said it would be fine because hot water is pumped) as well as 3 other mixers in the house with same hot/cold set up.

Looking online could it be the hot water is being overpowered by the cold, with mains then backfilling down the hot water pipe and filling the attic? I can see this can be resolved with a non return valve? And instead of fitting 4 non return valves can I fit one 22mm NRV on the flow from the pump? (Not the feed as this stops any ability to vent)

Thanks and sorry for the long winded post.

 

[ShaunCorbs]

Positive head or neg head pump ?

 

[GGg]

Positive Head.

 

[Burger]

Hi All,

Looking for some advice. The tank in the attic has been trickling out of the overflow for a few weeks now.

I have an open vented system with a hot water pump (Stuart Turner monsoon twin 3) fitted.

Have already changed the valve and float in the attic. Set it very low but water is above the float. Tested it fine know it shuts off the feed that way.

Also changed the thermostat on hot water cylinder, so tank isn’t getting too hot and venting over.

I do have a shower fitted with mains cold and tank fed hot. (Plumber at the time said it would be fine because hot water is pumped) as well as 3 other mixers in the house with same hot/cold set up.

Looking online could it be the hot water is being overpowered by the cold, with mains then backfilling down the hot water pipe and filling the attic? I can see this can be resolved with a non return valve? And instead of fitting 4 non return valves can I fit one 22mm NRV on the flow from the pump? (Not the feed as this stops any ability to vent)

Thanks and sorry for the long winded post.

It can be yes, a customer had a tap fitted and another plumber had changed the float valve twice. Turned out it was backfilling the cwsc (cold tank) and overflowing. I advised he fit check valves or change the tap.

 

[Burger]

It can be yes, a customer had a tap fitted and another plumber had changed the float valve twice. Turned out it was backfilling the cwsc (cold tank) and overflowing. I advised he fit check valves or change the tap.

If you want to check this then try and put your hand in the tank and feel where the cold feeds the cylinder

 

[GGg]

Ok thanks for the responses. Will try the feed later, if it is this, will one check valve suffice (on the outlet on the pump) or will I need one installed at each mixer?

 

[Riley]

Split coil in cylinder or faulty mixer

 

[Riley]

Ok thanks for the responses. Will try the feed later, if it is this, will one check valve suffice (on the outlet on the pump) or will I need one installed at each mixer?

does the pump do all hot in the house

 

[GGg]

does the pump do all hot in the house

Yes feeds the whole house.

 

[Riley]

Then just at the pump should suffice

 

[GGg]

Split coil in cylinder or faulty mixer

Mixers are brand new, how would I test a split coil? Wouldn’t the heating tank be draining?

 

[Riley]

Is your smaller f&e tank above or below the larger cold water tank

 

[GGg]

Is your smaller f&e tank above or below the larger cold water tank

Below I think? The plumber bloke tested the “levels” in the tanks and they were fine?

 

[Riley]

If the level of the f&e is above the cwsc then if the coil is split the two will try and level out.

 

[GGg]

If the level of the f&e is above the cwsc then if the coil is split the two will try and level out.

Ok thanks. Any easy way for me to check the coil?

 

[Riley]

That’s what I just said?? If the f&e is higher than the cwsc then if the coil is split then the water levels in the two tanks will try and level out

 

[Riley]

The test is, is the f&e water level higher than that in the cwsc

 

[GGg]

Sorry. Get you now. Will check.

 

[GGg]

So. Sat in the attic whilst the mixer taps where tested. Felt the feed at the bottom of the cw tank and it was sucking the water out quite powerfully, nothing being pressed back up?

The valve has now settled and the water is the correct level.

But in a day or so it will be overflowing again. I’m completely baffled. Picture of the F&E tank just in case I’m missing something obvious.

 

[Riley]

Where’s the f&e tank? Or is that the f&e tank?? I think you’re missing my point where is it in comparison to the cwsc

 

[GGg]

That’s the F&E tank. Which is married to the CWSC.
I checked the levels in both of them and the F&E doesn’t look higher.

 

[Riley]

Can we get a pic showing both tanks side on? “married to”?? I think you’ve missed the point. It may not be the case

 

[GGg]

Any good?

 

[GGg]

Think it’s the coil. Can see water going onto the CWSC when the hot water is turned on to heat up. (Nothing to do with mixer) tried to show a video but it won’t upload. Is that what would happen? The feed pipe down to the bottom of the tank is also getting warm.

 

[Riley]

Can’t really see the levels there. I’m guessing the water level in the f&e is lower though