Is there a right and wrong way to turn off Hot Water supply to taps??

TighterThanTwoCoatsOfPain

Phew, long thread title!! Hope there are some plumbers in the house..

Next DIY task of mine is to do a direct replacement of the utility room sink. Having done some investigation it seems that whilst there is no way to isolate the cold tap close to the sink itself (i plan to put in those little screw isolating parts!), it is connected direct to the mains and not the cold tank in the roof so can turn that off easily..

Question is really with regards to the hot system. All hot water to the hot taps is supplied by immersion heater. Having put on my deerstalker etc, it seems the pressure to the hot water taps is provided by a head of cold water from the roof tank filling the immersion heater from the bottom, pushing the hot water out the top of the tank?? Sounds plausible to me!

I tested last night that if I isolate the mains stop !!!!, and also the cold water (from the roof tank) supply to the immersion heater, after i ran the hot tap for a few seconds it stopped.

My questions are:

1) is this a safe (the correct / only) way to do what i want without draining the entire system. (dont want to risk collapsing the cylinder or anything :eek:
2) If so, is there a correct way to restore pressure to the system to avoid air locks? ie Immersion valve first, then Mains supply - or vice versa. It coughed and spluttered last night, but all seemed well after running taps for a few minutes
3) Anything else i should be aware of?

beefy2

There should be a 22-28mm gate valve (red) that should shut the cold supply to the tank off.

Or you can buy some rubber plugs/bungs from (Plumb-Centre) that fit inside the storage tank outlets in the loft,to save having to drain the whole thing down.

TighterThanTwoCoatsOfPain

cheers for quick reply......yup, thats the one i found which appear to do the job on the face of it...but not had much experiance of plumbing systems...

no danger of collapsing the tank or anything daft if i drain between the hot water between tank and the tap?

should i shut of that valve or the mains first? any paticular order to turn back on or doesnt it matter?

beefy2

Turn the mains off first (Just in case) then the gate valve,drain down do what you have to.

Keep the hot taps open and slowly open the gate valve to get rid of any air locks

You should be ok with it:beer:

TighterThanTwoCoatsOfPain

nice one... thanks. Thats the order that seemed logical, but always good to have it backed up without prompting!

Keep those fingers crossed for me!! :beer: