combi used as a system boiler

[Billy Bob Bob]

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?

 

[villa_tom]

Never seen it done.

But you can definitely do it on an intergas boiler.

 

[Billy Bob Bob]

my thoughts are tom if you can zone a combi,which i have many times its no different fitting a y plan system and using it as a system set up as long as you use one outlet for dhw from the boiler

 

[erpkid]

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?

It is the set up we have here. I have a WB which was a quick fix years ago but now have is S planned. Still combi hot to kitchen sink and downstairs loo.

 

[Masood]

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?

Why would you need to run any hot at all? I've never done it, but have heard of it being done and always assumed that was how people did it.

 

[Billy Bob Bob]

Why would you need to run any hot at all? I've never done it, but have heard of it being done and always assumed that was how people did it.

good point

 

[vern]

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?

Course you can Mark done a few as combi was higher output and cheaper than system etc

 

[galaxy_plumbing]

what about electric control on pcb. probably you would need to close some jumpers not to switch to dhw. just assumption 🙂

 

[erpkid]

Why would you need to run any hot at all? I've never done it, but have heard of it being done and always assumed that was how people did it.

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.

 

[Masood]

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.

Good point, well made! Might as well use it if it's there...

 

[neily01]

I have always thought it was a good idea as it can be cheaper for a combi over a system just have to be careful on electrics as some combis 24v switching on heating so zone valves are the way forward!

 

[Billy Bob Bob]

Course you can Mark done a few as combi was higher output and cheaper than system etc

my thoughts as well a megaflow 32 system is 100 quid less than a potterton titanium 40 combi,megaflow 2 year warranty titanium 7 years so 5 years for a hundred quid more

 

[mfgs]

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.

 

[vern]

my thoughts as well a megaflow 32 system is 100 quid less than a potterton titanium 40 combi,megaflow 2 year warranty titanium 7 years so 5 years for a hundred quid more

Just done one the same as I system 5 year warranty and combi 7 year got a good deal on the combi and the old boy always wanted an hot outside tap lol, got me the job! And him what he wanted and a 7 year warranty to boot!

 

[anz]

my thoughts as well a megaflow 32 system is 100 quid less than a potterton titanium 40 combi,megaflow 2 year warranty titanium 7 years so 5 years for a hundred quid more

Warranty will be void unless you have at least one outlet running off the 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🙂