Turning off the mains to a combi boiler

[imamartian]

hi,
forgive me if this question is similar to others, but the ones i've read didn't completely answer my question.

I want to refit my bathroom, and i will be turning off the water at the mains stop cock. However, i have a combi boiler....

Question 1 - do i just run the hot tap to drain the system down?
Question 2 - is it safe to completely drain a combi boiler?
Question 3 - is it sufficient just to turn the mains on again to refill the boiler?


Thanks

 

[nickso]

yes but some water will remain.

yes.

yes.

 

[chrishutt]

You need to understand that there are two separate lots of water in a combi.

Firstly there is a small amount of mains water which gets heated and then supplies the hot taps. This you can turn off and drain (simply open the hot taps) from boiler without any problems.

Secondly there is a much larger amount of heating system water which you probably don't need to drain or interfere with in any way (unless you're altering the heating system - e.g. new bathroom rad). Draining and refilling that side of the system is more complicated and should not be done unless you understand what's required.

 

[imamartian]

Thanks people.

Do i need to turn the boiler off beforehand?

 

[Agile]

You have not told us the make of boiler!

NEVER turn off the mains electricity to a combi boiler if it has a pilot light!

You can remove the cold water supply and still use the boiler for heating.

Tony