Running a Combi boiler without radiators - What do I need?

[dhutch]

How feasable is it to link the flow and return together and run the boiler without the radiators attached?

I have some work to do on the CH loop, adding a radiator, replumbing the tails on another and the like. As im only at the house weekdays I will be doing the work in the evenings after work so it may take several nights during which I need to be able to use the hotwater.

Obviously like most combis a loss of system presure shuts the boiler down, but if I add a pair of isolation valves just down stream, with a link between just boiler side, can anyone see anything wrong? As I would only be running the boiler in 'water only' mode I see no reason why they link shouldnt be 15mm, with an isolator for when the system is recommissioned?

Thoughts

Boiler is a Main 30HE fwiw.


Daniel

 

[dcawkwell]

No it will be fine.
Connect flow and returns pipes with a length of pipe.
Just so the boiler can circulate around on overrun.

 

[Netdragon]

consult the manual most boilers need a set amount for heat to be removed from the low water content heat exchanges most boilers have now days, ie a very small radiator under it.

This is primary to stop the heat exchanger getting too hot and suffer problems.

As long as the required heat loss is achieved there is no problem

 

[dhutch]

No it will be fine. Connect flow and returns pipes with a length of pipe. Just so the boiler can circulate around on overrun.

Most boilers need a set amount for heat to be removed from the low water content heat exchanges most boilers have now days, ie a very small radiator under it.

Right ok, so there is likely to be a requirment for flow, and or some heat rejection, I cant just cap them both off to hold the water in and presurise it.

Ive never noticed the flow/rtn getting warm when used in hotwater mode only but will look and a manual tonight and see if I can feel and heat in them. It wouldnt be much more work to put the isolation valve and link peice 6ft from the boiler, which would obviously increase the size of the loop, but easier not to given im not expecting run it like this for more than a fortnight.


Daniel

 

[RoughWaters]

You certainly cant just cap them off. Put a temporary rad in.