in hot water

[charliebenetti]

all i need is to know is i need to disconect my hot water pipe which goes to the mixer tap in the kitchen.I can turn off the mains to do the cold water but the hot water cylinder has not valves to close it off so i am guessing if i disconect the pipe from the tap (a lot of water!!!!!!)
HELP

 

[imamartian]

all i need is to know is i need to disconect my hot water pipe which goes to the mixer tap in the kitchen.I can turn off the mains to do the cold water but the hot water cylinder has not valves to close it off so i am guessing if i disconect the pipe from the tap (a lot of water!!!!!!)
HELP

get yourself to plumbing.... they'll tell ya what to do

 

[StephenW]

There's normally a gate valve between the cold water tank (in the loft) and the hot water cylinder. You turn this off and then gently open the hot tap until the water stops flowing. If, as you imply, you don't have this gate valve then you either have to empty the the cold water tank first (switching off the mains or tying up the ball valve to stop it refilling) or put a bung inside the tank in the outlet pipe to the hot cylinder.
Whilst the water is off make sure you fit an isolator into the pipe under the sink (and any other hot taps which don't have one) to make future maintenance easier.
I don't know if it's true, but I was told that you should open the hot tap gently once you'd closed the gate valve because a sudden vacuum could cause the cylinder to collapse inwards.

 

[Hugh Jaleak]

If the cylinder is correctly installed with an open vent then there is no danger of it collapsing. Cylinder collapse can happen, usually during cold weather if vent and cold feed were to freeze, opening a hot tap could cause a slight vacuum in the cylinder. The action of this vacuum can cause the cylinder to collapse as atmospheric pressure pushes in the sides....