Isolating water supply to replace plumbing

[Paul17088071]

Hi all

I’m replacing my stop cock and plumbing in the downstairs toilet. I have a gravity fed boiler system.

Other than turning off the mains supply outside, and opening all the taps in the house to drain the system, do I need to shut off/drain the upstairs water tank and header tank?

Many thanks in advance

 

[Wayners]

Any water isolators in airing cupboard?
That will turn flow off from tanks

 

[Paul17088071]

Many thanks for your reply. I’ve just seen this (runs to the smaller pipe in the second picture), will this turn off the flow from both tanks or am I looking for a second one?

 

[Paul17088071]

 

[Harria70]

The tanks feed separate supplies, one for taps / toilet and one for central heating, so that valve will only do one. Look for the central heating pump, the header tank feed will drop down behind it usually.
Now would be a good time to do away with the domestic water tank and come straight off the mains...so long as the pipe work is in good condition

 

[Paul17088071]

Ah fab thanks. I’ve just found this one which is opposite the other isolating tap, and makes sense based on location of two tanks in loft. Would this be the one?

 

[CountryFan]

View attachment 370692

If you’re turning off the main anyway and draining the hot and cold feeds then just the main stopcock is fine. Be prepared for some potential air locks though.

 

[Paul17088071]

I’ll turn off the main stop cock outside and also drain the taps. I may also isolate both the tanks just to be on the safe side aswell, is there any harm is doing that apart from the air locks?

Thanks for your help, appreciate it

 

[CountryFan]

No harm, but unless you’re carrying out heating work, no need to isolate the small feed and expansion cistern

 

[Harria70]

Yeah, that's a point. Only drain what you absolutely need to. Air locks in them old systems can be a nightmare to clear.

 

[ChrisJP]

Now would be a good time to do away with the domestic water tank and come straight off the mains...

Why would you want to do that? Having a CW storage tank means you have a backup in the event of a water supply outage - which is some areas seem to be becoming more frequent.

 

[Harria70]

I like to have hygienic coldwater for the bathroom, better pressure/flow for toilet. We are pretty good where I am for supply issues, maybe once a year for a few hours at most. I wouldn't have thought there were too many vented systems around nowadays with combi's.

 

[ChrisJP]

Having a non vented combi boiler and CH system doesn't preclude you having a CW storage tank feeding a HW storage cylinder. That cylinder can also have an electric immersion heater so you have a HW backup if/when the boiler has a fault.

 

[Harria70]

Would that be using the combi as a system boiler ( S-plan ) to heat the cylinder for upstairs taps and use the combi hot water downstairs ?

 

[gas112]

Don't touch any gate valves (red handles) in airing cupboard they have a habit of breaking in the closed position