Another hot water in the cold water storage tank question...

Joined
30 Dec 2019
Messages
39
Reaction score
0
Country
United Kingdom
Hi all. I am fully aware that this question has been asked multiple times and I have trawled through a lot of threads on this.

I am trying to diagnose an issue and was just hoping someone could confirm if I am on the right lines here.

The set up:
2x large storage tanks at same level in loft. One for cold water bathroom taps, one to feed hot water cylinders at ground floor.
1x small tank (F&E for CH) @ higher level than other two
3 flats being fed by this system (share of freehold/self managed block)

The issue:
Every so often the overflow pipe from the CWS tank (which feeds the HW cylinder) will run (with varying flow rates) for several days at a time. It may stop occasionally (I guess when someone is showering etc). Then the problem will go away for a while (months even) before restarting.

The last time this happened, I isolated the mains feed into the building and it stopped the overflow almost immediately (opening stopcock made it start overflowing again). I went up into the loft and to my horror the water was pretty hot to touch. The vent pipe (presumably from HW cylinders) end was slightly submerged in the water (which it seems is wrong); however, if the water was only as high as the ballcock valve dictated it wouldn't have been submerged. I got my neighbour to drain the tank to correct level and watched. No water was coming out of vent pipe so it must be from the outlets at the bottom of the tank. AN hour later the overflow was going again.

My thinking on potential issues:
- Dodgy mixer tap (probably kitchen) where mains fed, pushing hot water back into tank
- Failed thermostat causing overheating of water in cylinders
- Punctured coil in HW cylinder - I feel like this is unlikely as the ballcock in the F&E tank wasn't running whilst the overflow was happening

Any other ideas and things to look at? cheers
 
Sponsored Links
A mixer tap of some kind backfeeding mains to hot would account for what you have described.
 
A mixer tap of some kind backfeeding mains to hot would account for what you have described.

If that was the case, pipe connected to top of cylinder ( hot water supply pipe to your taps) will be cold
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top