combi used as a system boiler

[dancinplumba]

You don't need to have a hot run but it makes sense for occasional use. We have our timer set to have hot water in the evening. If I need to sort my mucky mits during the day there is no cylinder draw off and theoretically better economy.

Surely it less to draw off cylinder than for boiler to fire on full gas from cold to heat a bit of water to wash hands ?

 

[Nostrum]

Depends where the boiler is, and where the cylinder is, could save drawing off cold water before the hot comes through?

 

[mountainman]

never done this but as long as i run the hot outlet to at least 1 tap i cant see any reason why i cant use a combi as a system boiler?

I've done it many times as in some countries system boilers aren't imported.
Realistically if you look inside a modern system boiler it is identical to a combi without a diverter valve and plate hx.

 

[buckley plumb]

done it a few times in large houses having combi feed to one sink but no need to .

 

[Alpha man]

I have done it a couple time. I have always put the kitchen sink and/or utility room sink on the combi side of things and stored water for bathrooms etc.

Same here!

 

[rab250]

I have also done it. An alpha cd50 connected to an oso twin coil run on an s plan heating the offices also. Has a hw draw off for the cleaners to fill their mop buckets . Works brilliantly

 

[lame plumber]

if you dont use the hw side then wont the diverter seize up long term and cause issues. if the combi is already in situ, leave the close runs as is and just wack in an s plan on the heating/cyl side. If its an intergas, even easier to do, and youll have water whilst your working on it