combi boiler -one without the other ?

[JPC]

hi guys

1) can i run a combi for hot water if c/h side is drained down ?

2) can i run the combi for c/h if mains water has been turned off...thx

and a quick explanation would help me understand..thx

 

[croydoncorgi]

) can i run a combi for hot water if c/h side is drained down ?

No - because virtually all combis have an anti-dry-firing check that must sense sufficient water pressure in the primary circuit before the boiler will fire

can i run the combi for c/h if mains water has been turned off

Yes, but only if the boiler is pressurised to begin with. (If the mains is off, there'll be nothing to pressurise the boiler with.) But why would you want to?

 

[JPC]

so i can run the combi for c/h still if for example i turn mains off to fit a bath ?

on other point, drain down c/h but still use hot water..ur saying it cant be done.

i thought so but wanted to dbl check.
i'm doing up a flat and have took some rads off. i then thought i could drain down to move some rad pipework and that made me think about the above question.

thx

(just tought, below the filling loop could i splice in and connect flow and return and then fill that very small loop via the filling loop, could i then use hot water (central heating off, but c/h side would be pressurised)

 

[EliteHeat]

just tought, below the filling loop could i splice in and connect flow and return and then fill that very small loop via the filling loop, could i then use hot water (central heating off, but c/h side would be pressurised)

You could do that - the boiler doesn't know that it hasn't got any radiators, don't make it too tiny though, the boiler has to dump heat when you turn off a hot tap.

 

[Agile]

Most boilers will work on DHW if its pressurised to start with and the heating isolating valves are then closed.

Only suitable for a shorter time though.

Tony

 

[JPC]

thx all