Wood burning back boiler to central heating

[K-Man]

Hi,
What I would like to do is connect a wood burning stove with a back boiler into my oil fired central heating system. The central heating system is closed loop running at 1.5 bar. Is this possible ?

 

[Breesey]

How would you control the system?
Presumably this would be supplying heat to the primaries constantly and uncontrolably. Don't think this allowed now ref Part J

 

[Onetap]

Hi,
What I would like to do is connect a wood burning stove with a back boiler into my oil fired central heating system. The central heating system is closed loop running at 1.5 bar. Is this possible ?

Could be done.

The solid fuel stove should be open-vented with a heat-dump radiator under UK regulations, should be installed by a Hetas bloke/blokette; like CORGi for solid fuel.

http://www.hetas.co.uk

You'd need a heat exchanger to isolate the two systems because they're at different pressures. The usual method is to have the solid fuel open-vented and heating the water in a thermal store. The sealed system is connected to a heat-exchanger coil in the thermal store.

You could do something similar with a plate heat exchanger. Both primary & secondary flow through the PHX need to be pumped, due to it's high hydraulic resistance.

 

[Breesey]

Are you saying you could connect the stove and the heating to one hot cylinder that has two heat exchangers in it?
How do you satisfy regs regarding the control of the stored water temp? Is this just done by closing the primary flow to the cyclinder with a stat controlled two port and diverting through the heat sink rad?

 

[Onetap]

Are you saying you could connect the stove and the heating to one hot cylinder that has two heat exchangers in it?
How do you satisfy regs regarding the control of the stored water temp? Is this just done by closing the primary flow to the cyclinder with a stat controlled two port and diverting through the heat sink rad?

No, I'm not.

The thermal store is an open-vented cylinder full of boiler water from the solid fuel boiler. Do a search for thermal stores on this and other forums.
The heat is transferred to the sealed system heating system by circulating that water through the heat exchanger coil immersed in the thermal store water, or through a PHX.

A domestic hot water storage cylinder is completely different beast. The stored DHWS temperature is usually controlled by a 2-port spring-return zone valve. Unvented DHWS connected to a solid fuel system is not usually recommended, although it can be done legally.

 

[Breesey]

Ok got ya! Thanks.

Is temp of the store regulated only by the (presumably) appropriately sized rad heat sink?

 

[Balenza]

Hi,
What I would like to do is connect a wood burning stove with a back boiler into my oil fired central heating system. The central heating system is closed loop running at 1.5 bar. Is this possible ?

Go for a stove which offers preheated secondary air - this provides better effiiency and cleaner burning than for standard wood stoves.
"Clearview" are one such stove and advise against adding a boiler to a stove as it will cool the firebox and impair clean combustion.

My brother in law has a standard one fitted in his lounge but with no back boiler.
He usually leaves the door open from the lounge to the main hall way of his bungalow and he finds the heat from the stove will migrate around the house anyway.

 

[K-Man]

Hi,

Thanks very much for your help. The question was for a guy I work with, so i'll pass on all the information.

Thanks Again

PS Sorry i've took a while replying but I tend to come on here at work, and I was off until tonight