Tying in a wood burner to a central heating system?

[BrianV]

You still need electric for the pumps. I'm forever intending to fit a solar panel and battery to power the pumps if needed.

But with an electric cut if set up right at least you still have heat & hot water.

 

[Kidds]

But with an electric cut if set up right at least you still have heat & hot water.

You could probably get away with it if you are very familiar with your system but how do you manage excess heat?
Mine has one big rad on a gravity loop for safety reasons but it would scare me if the electric went off with the fire fully stoked and we had gone out. The pump needs to kick in to shift the hot water before it starts boiling.
Plus all these modern systems seem to insist on having motorised diverter valves in there somewhere.
Even back in the days of open fires and back boilers the old biddies would be running off the hot water and putting wet teabags/potato peelings on the fire when it got too hot. That is what the pump does these days, manages the heat.
With a solar panel and battery, doesn't need to be complicated or even expensive, my log burner will do heating, cooking and DHW. Son in Northumberland has had no electric yet so no heating cooking or hot water since the storm.

 

[BrianV]

You could probably get away with it if you are very familiar with your system but how do you manage excess heat?
Mine has one big rad on a gravity loop for safety reasons but it would scare me if the electric went off with the fire fully stoked and we had gone out. The pump needs to kick in to shift the hot water before it starts boiling.
Plus all these modern systems seem to insist on having motorised diverter valves in there somewhere.
Even back in the days of open fires and back boilers the old biddies would be running off the hot water and putting wet teabags/potato peelings on the fire when it got too hot. That is what the pump does these days, manages the heat.
With a solar panel and battery, doesn't need to be complicated or even expensive, my log burner will do heating, cooking and DHW. Son in Northumberland has had no electric yet so no heating cooking or hot water since the storm.

View attachment 1001194

You're right solar panels would be an idea addition, we find with an electric cut we close the wood burner right down & the water tends not to boil, if it did it is not a sealed system & if set up so you can draw off hot water for a nice hot bath that takes care of things. Obviously it only gives you one warm room but with the internal doors open it's surprising how the warmth spreads through the house.

 

[Highland Mule]

With a solar panel and battery

If it's just the one circulation pump you need, I'm not even sure I'd bother with the panel - just keep a charged 12V lead acid and a small inverter handy, plus know which wires to swap to energise your pump. Maybe get a tame sparky to give you a changeover switch in the heating cupboard ?

 

[BrianV]

If it's just the one circulation pump you need, I'm not even sure I'd bother with the panel - just keep a charged 12V lead acid and a small inverter handy, plus know which wires to swap to energise your pump. Maybe get a tame sparky to give you a changeover switch in the heating cupboard ?

Or simply put an additional circulating pump into the system constantly wired to the inverter alone.

 

[Highland Mule]

Or simply put an additional circulating pump into the system constantly wired to the inverter alone.

Would they not cause trouble for each other if in the same pipe loop? I can't imagine them being happy windmilling so would need some clever parallel plumbing to avoid problems.

 

[HatsOff]

I looked into it but found the extra cost/hassle was better to put the money to the ASHP and use log burner as a spaceheater if needed (and/or reduce electricity use)

 

[BrianV]

Would they not cause trouble for each other if in the same pipe loop? I can't imagine them being happy windmilling so would need some clever parallel plumbing to avoid problems.

You might need to find out, we put an additional pump into the system 25 years ago to boost the flow at certain times but the extra pump does not impede the flow of water at all when it's not in use.

 

[organicguy]

You still need electric for the pumps. I'm forever intending to fit a solar panel and battery to power the pumps if needed.

I thought of that as soon as I posted!
In our large farmhouse we have a 13kw log burner with back boiler, a jetmaster open fire which are linked with 15 radiators, with a pump,and two thermostatless radiators in case of a power cut. Open circuit with a header tank.
We have occasionally boiled the system when someone has turned the power off to the pump. Never been an issue because the fires are never that stoked if no one is here.
Want to put GSHP in stable conversion and mean me thought if we fed a bit of wood heat into the system we could save some electric.

 

[Mur Huwcun]

I thought of that as soon as I posted!
In our large farmhouse we have a 13kw log burner with back boiler, a jetmaster open fire which are linked with 15 radiators, with a pump,and two thermostatless radiators in case of a power cut. Open circuit with a header tank.
We have occasionally boiled the system when someone has turned the power off to the pump. Never been an issue because the fires are never that stoked if no one is here.
Want to put GSHP in stable conversion and mean me thought if we fed a bit of wood heat into the system we could save some electric.

If you can insulate the conversation properly and seal every gap you can think of the GSHP won’t need much extra help plus you cant if you claim RHI use additional heat sources.

 

[HatsOff]

I thought of that as soon as I posted!
In our large farmhouse we have a 13kw log burner with back boiler, a jetmaster open fire which are linked with 15 radiators, with a pump,and two thermostatless radiators in case of a power cut. Open circuit with a header tank.
We have occasionally boiled the system when someone has turned the power off to the pump. Never been an issue because the fires are never that stoked if no one is here.
Want to put GSHP in stable conversion and mean me thought if we fed a bit of wood heat into the system we could save some electric.

Hot water is a fraction of the energy demand of heating the house. As a log burner works great as a space heater (and won't affect rhi) it's much more straightforward to leave the two disconnected.