Hot Water Shut-off Valve?

[Jerry974]

Hi Everyone,

I have recently bought a house and as part of the re-decorating I am planning to replace the taps in the bathroom. However, I have no idea how to shut-off the hot water supply so I can remove the hot water tap safely.
The boiler (in the kitchen) is a Classic FF350 Gas Boiler and I believe the central heating & hot water system is a open vented one as it look like this (with the two tanks in the loft):

There are several pipes with valves coming in and out of the hot water cylinder (Hercal) see picture below but I don't know which one is for the hot water supply.

Can anyone tell me how to shut off the hot water supply?

Many thanks.

Jerry

 

[McCombi]

its the red valve that is on the pipe that comes off the top of your cylinder in the centre.

 

[giant7]

The pipe on the left that you have marked cold is the feed from the cold tank in the loft to the hot water cylinder. If you turn the red gate valve off this shut off your hot supply. However, gate valves can often seize up or pass water so you may have to turn the cold supply off to the tank and run your hot taps until the cold water tank is empty which will no longer supply water to the hot water cylinder and allow you to work on your hot taps.

 

[JohnD]

one of the cold pipes on the back wall (with a round "wheel head") will go into the bottom of the cylinder. That's the one you need to close. Most likely to be a 22mm one and probably the one with the drain cock showing. The cold pipe with the T shaped handle will (should) be the stopcock for mains cold going up to fill the cold water loft tank.

the other 22mm cold pipe probably feeds the cold bath tap. Tie some labels on the valves once you've identified them. This will be useful in future

brassedoff is not mistaken, that's the pipe the hot water come out of the cylinder. Whether you close the pipe that fills the cylinder, or the one that it comes out of it, the hot tap will stop running.

If cold water stops going into the bottom of the cylinder, hot water will stop coming out of the top

 

[McCombi]

Just a suggestion but Im not a fan of these type of gate valves, I tend to find they can pass when meant to be closed or can fail altogether after lots of use.

Maybe worthwhile fitting a lever style valve which is more reliable after frequent use.
Possibly I've just been unlucky in finding lots of faulty red handled wheel types? Im not a plumber to trade I jumped straight in to gas appliances so maybe a more experienced plumber can add to this and could also be beneficial knowledge to me too.

 

[Jerry974]

Thanks a lot for your help. I've closed the valve on the left and after a few minutes the hot water stops running out from the tap.

While we are on the subject do you know what that switch is for? When I turn it on an orange light comes on but I have no idea what it does so I keep it turned off.

 

[JohnD]

I would have said an immersion heater, but I can't see one in your cylinder. Photograph the top.

Maybe an anti-frost heater in the loft?

BTW your pump control is set to Manual, High. It should normally be pointing at the dot.

 

[Jerry974]

I can't see any immersion heater (see picture):

Thanks for the info about the pump.

 

[McCombi]

looks like the switch is there for the possibility of fitting an immersion heater to the cylinder. You may find that there is also another switch that has to be on before power will be at the switch, probably in the kitchen.

If you have a multimeter and are competent then you can prove whether the switch is live or not and whether its wired in series with another switch from the kitchen as i mentioned. (might not be in the kitchen though)

 

[Jerry974]

I'll ask a friend of mine to check if the switch is live, thanks.

 

[JohnD]

When I turn it on an orange light comes on

then it is live.

 

[McCombi]

When I turn it on an orange light comes on

then it is live.