Can a stove with a boiler be used to supplement a gas boiler?

I'm planning to get a gas combi boiler to provide hot water and heating for a 3 bedroom semi-d. I love the look of an open fire and was thinking of getting a solid fuel stove. I know some of these come with back boilers. I was wondering if I could use this instead of the gas combi when it was lit - I wouldn't want to use it all the time. Any idea how much this would cost?

Thanks,
g

you can't have a solid fuel appliance on a pressurised system as soild fuel has no safety features to shut it down if it over heats. It is also better to have a hot water cylinder connected to stoves to work as a heat dump and since you have a combi you probably don't have one.

Thanks for the reply. I haven't got any boiler as of yet - I'm trying to plan what would be best so I'm not set on any particular kind yet.

Hi
There is a way but it means linking the two systems (pressurised/open vent) without letting the water mix i.e. a heat exchanger. The heat exchanger absorbs the pressure differences. What you have to do is have a good heat sink in the open vented (stove) incase the power goes off (this can have a mororised valve that switches if the power goes off). A stat in the open vented turns on the pressurised system pump to take the heat. It is a bit of a balancing act.

I have never come across that, how would you stop the extra heat impacting on the combi, if the combi stat stops calling for heat?

Hi Gary
It has been a while since Ive been on. Does this answer your question? If the stat stops calling for heat, the pump on that system (combi) is turned off i.e no circulation and it wont be pulling heat from the exchanger and from the stove system. However the stove system is free to circulate (open vented). The one issue with this is the possible build up of crud in the exchanger so filters are needed.

Gary,

May I ask, have you just started your gid?

It would work in theory, have you ever seen one in practice? I never have. I would suspect the heat exchanger would have to be pretty big to heat the radiator system indirectly.

bottom line is that's it's not practical to tie a casual fireplace into a day to day heating system, the cost doesnt justify. just enjoy the fireplace when you light it and dont worry about having all that heat going up the chimmeny wheder the fire is lit or not.

dmv said:

bottom line is that's it's not practical to tie a casual fireplace into a day to day heating system, the cost doesnt justify. just enjoy the fireplace when you light it and dont worry about having all that heat going up the chimmeny wheder the fire is lit or not.

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The OP is referrering to a stove.

ya most causal stoves work the same way though, ie not tied into any system

If there is a secondary heat source on the same circuit as a domestic gas boiler and the gas boiler is the primary heat source, you are going to possibly have problems with overheating due to the fact the primary heat exchanger is so small, when the gas boiler goes off on the stat it just cuts the gas not always the pump, the boiler will have to dump the heat either by the fan running on or normally the pump running on, by adding a funky heat source you are "possibly" reducing the ability of the boiler to dissipate the heat, which would be very important if the safety overheat went and the pump ran on pulling in heat from the secondary source, this would be brown undergarment time. By fitting a secondary heat source you are moving away from what all manufacturers i know of would allow you to do with their boiler and you would be outside of IS813 as the gas boiler would not be fitted as per manufactures instruction. Gary.

DGOBS said:

Gary,

May I ask, have you just started your gid?

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Tony, Tony, Tony what makes you think that, could it be there's a over confident, over fed, over annoying moaner at the back of your class, don't know anything about it but i bet he's thinking a 3 o'clock finish woud be great, Gary.

Haha.....was thinking that when you retold the story of 'the corgi incident'

Unfortuneatley I won't be giving that class again, as I was only standing in for the usual instructor (you will like him, as he has lots of hands on experience) I am only there on Fri/Sat

Drop me an email, and I'll get a copy of that usb to you also that I promised

tony@oilburnerservices.com

talk soon mate

(ps, didn't think you were a moaner, very dead class!, at least someone was talking!)

Thats Mad, I forget its a small Island when you work in certain industries.

Gary is right when he says the boiler warrenty would be void if it was not fitted per manufactures instructions.
You wouldn't want the hot water from the second heat exchanger being pumped through the primary exchanger. So a second pump external to boiler would have to be fitted on a reverse loop with non return valves and the like.

its possible from an experiment side of things as long as the right controls where used but I can't see why anyone would bother to be honest.