Changing a kitchen tap - combi boiler system

mgns

Hi, I need to change the kitchen taps but haven't done any plumbing diy since we changed from a gravity to a sealed system. I would like some advice on the safest way of turning off the water - draining the water pipes - turning the water back on, so not to damage our newly installed Vaillant combi boiler.

There is only a mains stopcock and no isolating valves on the taps. Do I need to switch the boiler off or is turning the hot water temp to zero enough?

Thanks for your help.
mgns

muckybutt

If it were me then id freeze the pipes and put isolating valves on both, always freeze on or just before a bend, that way it wont blow out ! do one then the other, dont do them both at the same time.
No worries then of draining down and refilling

phill99

You don't need t drain tyhe system down on a combi. Turn the boiler off at the mains. Turn off the main stopcock. Do the work (install isolating valves while you are doing it). When its done, turn the stopcock back on and then turn the mains back on.

martinthebandit

phill99 wrote: »

You don't need t drain tyhe system down on a combi. Turn the boiler off at the mains. Turn off the main stopcock. Do the work (install isolating valves while you are doing it). When its done, turn the stopcock back on and then turn the mains back on.

is the right answer, simple enough job to do

keystone

muckybutt wrote: »

If it were me then id freeze the pipes and put isolating valves on both, always freeze on or just before a bend, that way it wont blow out ! do one then the other, dont do them both at the same time.
No worries then of draining down and refilling

!!!!!! - freezing pipes at mains pressure is just such a bad idea and poor advice IMHO.

As stated just turn water off at the stop tap and follow Phils advice. Simples.

Cheers

muckybutt

keystone wrote: »

!!!!!! - freezing pipes at mains pressure is just such a bad idea and poor advice IMHO.

As stated just turn water off at the stop tap and follow Phils advice. Simples.

Cheers

Thats your opinion !, ive done it loads of times for repair work and never had one blow yet.

mgns

Thanks to all for the advice.

I guess this is the plan:

1) Switch off Combi boiler via front panel.
2) Turn off mains water via internal stopcock.
3) Turn on kitchen taps to drain any water left in them.
4) Change taps.
5) Turn mains stopcock back on.
6) Run water through taps to check things are ok and clear any trapped air.
7) Switch boiler back on.

cheers
mgns

martinthebandit

mgns wrote: »

Thanks to all for the advice.

I guess this is the plan:

1) Switch off Combi boiler via front panel.
2) Turn off mains water via internal stopcock.
3) Turn on kitchen taps to drain any water left in them.
4) Change taps.
5) Turn mains stopcock back on.
6) Run water through taps to check things are ok and clear any trapped air.
7) Switch boiler back on.

cheers
mgns

thats a good plan

http://www.ultimatehandyman.co.uk/diy_plumbing_replacing_basin_taps.htm

may be worth a read