Isolating hot water

[Carlos_UK]

Hi, the mixer tap on our kitchen sink is in need of replacement, its white although a lot of the "paint" or whatever makes it white is flaking off and a few days ago we started having trouble turning the cold tap off, so thought now is the time to replace, unfortunately there is no isolation valves fitted to either hot or cold supply, the tails on the hot are soldered to the pipe and the cold is connected by a compression fitting, so to replace would mean cutting pipes, but with no isolation valves would be tricky, especially the hot side, so I've opted for replacing the valves instead as a short term solution, cold was easy as just turned off main stopcock also under the sink, and then headed for the airing cupboard to turn off the supply to the cylinder (vented) only to find that the gate valve is well and truly stuck, so opted to do it "live" as the hots obviously not high pressure, which has made the taps work perfectly again, but the question is, how can I shut off the hot water supply to replace the tap (and fit isolation valves) in the not to distant future?

I've read that you can just turn of the main stopcock, run a hot tap and wait for the header tank to empty, but have also seen this can introduce airlocks into the system?

Now I'm sure the easiest thing to do is call in a plumber to sort it out, but I do enjoy doing these sorts of jobs myself and building up my man points!

Many thanks

 

[woodytheplumber]

best way is to drain down replace gate valve for a full bore leaver handled valve in my opinion but you could always snatch a comp or pushfit iso in if you are struggling just open as many other hot draw off points and be quick I do this quite regular in many situations as many others will also but I am experienced and still get caught out from time to time so my over all advice is drain down replace gate valve with lever valve add full bore iso's to every other outlet and refill and if airlocks crop up force them out

 

[Neil K]

Turn off the mains, drain the tank in the loft. Leave all taps in open position, change the offending gate valve for a new one or better still a lever valve. Turn mains back on, refill tank, leave all taps open to clear airlocks. When taps are running for couple minutes turn them off. Let tank fill. Brand new cold feed to cylinder valve job done

 

[Rybo_1]

You seem brave by doing the hot live, how about bunging the tank connector which feeds the cylinder, open hot taps and then change the gate valve for a lever valve

 

[Carlos_UK]

Thanks for your replies guys (as always) I know I said that I didn't want to call a plumber as I'd rather do it myself, but I have British Gas Homecare 200 and it has just made me wonder if they would replace the gate valve under this agreement as its in a bit of an awkward position?

Might be worth a call!

 

[Neil K]

Is it stuck open or stuck closed? If stuck open then follow my advice and stick one after it

 

[Carlos_UK]

Is it stuck open or stuck closed? If stuck open then follow my advice and stick one after it

Its stuck open, that's a good call to stick one in elsewhere, never thought of that!

 

[goz666]

Get some WD40 on the shaft, small spanner and give it a wiggle. If it goes close it but not overtight.

 

[Carlos_UK]

Thanks, I'll give that a go! Is it not a regulation that isolation valves are fitted to taps, or is it just good practice as the only supplies that have them in this house are the toilet cisterns?

 

[helpsy]

It's good practice to fit isolation to taps but not a regulation. You do however have to fit them where there is a float valve or instantaneous water heater.