Mixer tap making cold pipe warm

[Hic777]

You can easily test which of your outlets are mains fed by closing your main stopcock and seeing which no longer run cold water.

It does beg the question as to why the Cwsc was left in place.

I don't have a shower in, it is currently capped off but I can remove that when turn stopcock off and see.
Regarding the CWSC still there, the pressure in the kitchen and outside tap which are both mains seems good so maybe lazy plumbing or they weren't sure if piping could cope with increase in pressure? We've only had the house a few months so all done by previous owners.

 

[dal5band]

Cutting through the jargon, what you seem to have is a combi boiler which means the hot water is at mains pressure ( no hot tank). Your cold supples to some taps are at low pressure from the cold tank, very low in fact because its a bungalow so the tank is not very high. With one high pressure and one low pressure supply you cannot have basin mixer taps or shower mixers. No shower pumps either. Get a plumber who knows what he is doing! Usually, with a combi boiler installation, all the cold supplies are upgraded to mains and no tanks are left.

 

[Hic777]

Cutting through the jargon, what you seem to have is a combi boiler which means the hot water is at mains pressure ( no hot tank). Your cold supples to some taps are at low pressure from the cold tank, very low in fact because its a bungalow so the tank is not very high. With one high pressure and one low pressure supply you cannot have basin mixer taps or shower mixers. No shower pumps either. Get a plumber who knows what he is doing! Usually, with a combi boiler installation, all the cold supplies are upgraded to mains and no tanks are left.

Thanks. If the decision is made to take the storage tank out then a plumber will be recruited. I won't know until I go back and see if the previous shower was connected to the tank or comes off the mains.

 

[Hic777]

Just thought I'd let you know how I got on. Put a non return valve on the cold feed which has solved that problem. Pressure is low but it was anyway due to being tank fed.

Also had a look and the shower feed does come off the mains (teed off before the feed goes into CWSC) so now I know I can get a decent thermostatic shower.