[telecom69]

Ive just had a Combi/condensing boiler fitted after years of being on the old system of a storage tank etc, my question is how do I change the washer on a hot tap with this new system ? the only shut of of any kind is the stop tap into the hose ....whereas with the old system I could shut off the hot water via a valve under the header tank ....thats now all gone...

[JohnWill]

You're liable to burn your fingers in the attempt.

Obviously, you'll have to drain the system to change the washer. You'll also have to make sure the boiler doesn't fire up while it's dry, so you should turn that off.

[blues_harp28]

Hi as has been said..switch off the boiler..should be a 3 amp fuse switch near the boiler.
Under the Combi boiler there is the Gas inlet and the water inlet.
There should be a cover you can remove to gain access.
They will be labelled Gas..Water.
Using a screwdriver turn off the water supply..it's a valve included in the 22mm copper pipe.
Turn on the Hot tap to discharged any water in the pipes and change the washer.
MOST important...once you turn the water back on..you will need to recharge the water system.
You will see under the boiler a looped hose with two taps.
On the front of the boiler is a gauge showing the water pressure.
It needs to be set at between 1 and 2 bars pressure.
As you have in effect drained the system..it will show none or very little pressure.
Slowly turn on the taps x2 to the looped hose and watch the water pressure rise and stop it at between 1-2 bars.
When it reaches that pressure turn off both taps.
That will now refill the boiler and you can then turn the boiler on.
Sounds harder than it is..let me know if you have any questions.

Edit.
Before turning on the electricity supply to the boiler.
Run hot and cold taps to the kitchen sink to clear any air between the boiler and sink.

[JohnWill]

Much more complete post than mine. You must have one of these.

[telecom69]

Many thanks to both of you for the replies but first prize has to go to blues_harp28 for such a well presented way to do the job,it really was so easy to understand (never dreamed of looking for in-line service valves ) understand about the flexible loop hose etc and pressurising thanks again,wonderful stuff

[JohnWill]

Have to agree, he really laid it out well.