Back Boilers.....adding to systems

[RW]

Hi all,

We have a solid fuel fire with a door on the front in our cottage which does not do anything more than throw out lovely heat and roast Chestnuts in the winter when we fancy lighting it. At the rear is a back boiler not doing anything at all. Not plumbed in to anything. The unit has a "draught" adjuster to enable the burn to be regulated quite finely. It all came from a cottage of a similar size as ours and ran DHW and Heating.

Now, as a good friend is an aboriculturalist and can supply more logs than you want to shake a stick at, we *could* use the heat generated to supplement the existing gas combi-boiler heating system.

At the mo' 6 rooms, approx 11ft square by 7ft 6 tall. Expect the bathroom which is only 8ft square.

Could I actually add supplementary rad's in positions (Such as under the windows) to improve the heat situation as at the rate fuel prices are rising I would rather burn free logs and distribute the ash over the garden. ?

Or would it be adaptable to add it into the existing circuit ?

Clean air act etc etc notwithstanding ;-)

[robgraham]

You have asked about two options, neither of which I fear are possible, but no doubt there will be someone along to say I'm wrong.

You have to be aware from the beginning that any hot water feed from a solid fuel source should be a gravity feed so that in the event of a power failure, the heat source can continue to dump heat into a reservoir, be that a tank or radiator in an upper room.

And there you will see the answer really to your two options - you need a DHW tank (either a normal DHW tank or thermal bank/store) which you won't have because you got rid of it in favour of a combi. And then you ask about supplying radiators within the room - that could be done with a seperate circuit from your CH system as it will have to have the gravity dump somewhere upstairs.

Rob

[RW]

You have asked about two options, neither of which I fear are possible, but no doubt there will be someone along to say I'm wrong.

You have to be aware from the beginning that any hot water feed from a solid fuel source should be a gravity feed so that in the event of a power failure, the heat source can continue to dump heat into a reservoir, be that a tank or radiator in an upper room.

And there you will see the answer really to your two options - you need a DHW tank (either a normal DHW tank or thermal bank/store) which you won't have because you got rid of it in favour of a combi.

No I didn't. The existing combi set up was here before we moced in.

And then you ask about supplying radiators within the room - that could be done with a seperate circuit from your CH system as it will have to have the gravity dump somewhere upstairs.

The roof is an option for the required tanks.

[Owain]

Dunsley Neutraliser

[RW]

But according to them "Please Note: The Neutralizer will not work on a sealed central heating system."

Am I correct in stating that a combi is a sealed system ?

[robgraham]

Yes I've got one of those with a normal DHW tank and an oil boiler. The wood burner has a differential thermostat on it that switches off the oil burner when the stove is hot. Rob

[Owain]

Not necessarily, although it may very well be.

Possibly it could be converted to an open vented system?

Owain

[Andy Dingley]

It doesn't have to be. There has to be a gravity circuit to act as a heat dump (small radiator upstairs with the valves always open) but there's no reason why the main heat circuit (i.e. a coil in a thermal store) can't be pumped instead. Obviously you lose heating after power failure, but this is sufficient to cope with the real need: that of dumping residual heat.