Turning off hot water (combi-boiler) to work on taps

[NeilPalfreyman]

This is a bit of a newb question, so apologies!

I need to take a hot tap apart to either repair or replace it and need to (obviously) turn off the hot water.

Our boiler is a Worcester 35CDi so hot water is "on demand" from the boiler. I don't seem to be able to find a valve to shut off the "domestic hot water out" so how do I do this?

Is it just a case of turning the boiler off, turning the cold feed off (at the mains stopcock) then opening the tap to drain?

If so what about when I turn things back on? Do I have to do anything to prevent damage to the boiler?

 

[Burnerman]

Just turn off the mains supply at the stopcock - this will allow you to get on with your project.
Minimal water will escape!
John

 

[3DGuy]

I'd turn off boiler and water inlet to the house.

I assume there are no isolators under the tap that you can just localised shut off? If not I suggest when the water is off and the boiler to install a couple

 

[NeilPalfreyman]

I can't locate any isolators and was thinking of putting one in whilst I'm at it. Wouldn't it be better on the "domestic hot water out" of the boiler so I can use it for work on anything else "downstream"?

Thanks for the replies so far, btw.

 

[3DGuy]

Well usually you would put them on any outlets ie taps, toilets and the like. Reason being if one causes a problem you don't loose hot/cold to the rest of your house. IE our show is fed from a separate feed than out bath. If one started causing problems I could isolate one and use the other with no issues.

For our bathroom I have 2 full bore isolators to the room to shut it all off, then separate ones for the toilet, hot and cold for the sink, hot and cold for the bath and hot and cold for the shower

I wouldn't put one right after the boiler as if you wanted to isolate the house, you can just shut off the power to it and the water mains anyways. besides if you were working on a tap you'd need to shut off the cold inlet anyways as well as the boiler. So either way the results the same. Unless you have local isolators to the fittings.

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• 3DGuy
• 24 Mar 2014
• 1

Here's an example. This is accessed by means of a hidden tile. That rooms been fully tiled so we have the 2 yellow handles for room isolation (full bore). Then the Blue/Red for the Bath (full bore), then the right 2 are smaller bore for the sink, and there is one under the bottom yellow handle for the toilet. The shower is isolated from the roof as the pipes drop down from the boiler above.