Basic Question

[gman76]

Other than a mixer shower, do cold water header tanks usually have separate feeds for the hot water cylinder and bathroom cold tap feeds, or is it normally from the same one?

Reason I ask is, I need to change a cold tap washer & hoping I can isolate the feed from the airing cupboard (feed to HW cylinder).

Any help appreciated.

 

[newbuildinstaller]

yes. There will (should) be a gate valve in the loft for the bath cold tap. Sometimes the bath cold is directly from the mains though. You can tell as the cold will have a much higher flow rate then the hot if it is mains fed.

 

[gman76]

That is what I didn't want to hear, the bath cold is def. feed from the tank - as is the electric shower (clearly fitted by a fool).

There are two gate valves in the airing cupboard on 22/28mm pipes, one feeds the HW cylinder, the other I'm not sure of.

I'm thinking I need to turn off the rising main & drain the header down?

 

[Burnerman]

You can either plug the header tank outlets and expansion pipe or turn off the house stopcock before you drain down....opening the bath cold tank will drain down the header, leaving most of your hot water in the copper cylinder.
If the house stopcock is seized, then tie up the tank ball valve.
(I just find old gate valves either seized solid or leaky when they are turned back on, and I prefer to leave them alone. Just my opinion though!)
John

 

[Gasop]

That is what I didn't want to hear, the bath cold is def. feed from the tank - as is the electric shower (clearly fitted by a fool).

There are two gate valves in the airing cupboard on 22/28mm pipes, one feeds the HW cylinder, the other I'm not sure of.

The other one is most likely to be the cold water down service. Just turn it
off and see if the bath tap stops running.