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BIOMASS => Solids: eg. Wood/Woodchips/Pellets/Sawdust => Topic started by: mr_magicfingers on June 11, 2020, 01:08:56 PM



Title: adding central heating to the boiler stove question
Post by: mr_magicfingers on June 11, 2020, 01:08:56 PM
Hi all, several years ago, during our renovations of the cottage, we put in 6kw of solar, an immersun (since replaced with Eddi) and a couple of Woodburning stoves, one dry to heat most of the downstairs and a Dunsley Yorkshire boiler stove which heats one room and the thermal store during the winter. This system has been a great success. The 300l thermal store gives us mains pressure hot and cold water, the PV & Eddi give us free hot water for probably 9 months of the year and the Yorkshire boiler and thermosyphon gives us hot water for the rest of the time costing only my time and the fuel for the chainsaw.

When we spec'd the thermal store, we had an additional central coil built into it which is piped to three radiators upstairs with a pump, the idea being to get a bit of extra warmth in the morning in the winters, from the heat stored in the thermal store overnight. In the end, we've hardly used that option.

However, we're now doing the final renovations upstairs and opening two bedrooms into one open office/craft space as my wife's now working from home for the next few years and needs a better office space. The only other heating upstairs is a single storage heater on the landing and so I'm wondering about options for the radiators we currently have. The two options involving the woodburner I see are to keep it as is, running the wood stove that heats the thermal store and continue running the rads off the store. The other option is that the Dunsley stove has two sets of connections on it, only one is currently in use, and I could fairly easily add pipes onto the unused connections and run them directly via the pump to the radiators instead of through the thermal store.

I think the latter would be more efficient but uncertain if there's any issues having two different systems connected to one stove. The simple thermosyphon from the boiler to the thermal store in the room above is efficient and has run without a hitch for 6 years and I'm wondering if adding an additional pumped system to the stove would cause any issues.

The photo in the manual shows a system like this, I'm just really wondering if it's worth adding the extra piping and taking the rads off the thermal store and putting them directly onto the woodburner itself.



Has anyone done anything like this with their wood fired heating system before?


Title: Re: adding central heating to the boiler stove question
Post by: daveluck_uk on June 11, 2020, 01:45:33 PM
hello Magic, will be watching this post with interest....I have a similiar set up now and have often thought aboyt heating the rads direct rather than through the store.

one point to consider...If you go direct with the radiators it means that the fire will need to be on to supply the heat. So you couldnt fire up the central heating pump first thing in the morning to take the chill off the rooms unless you had the boiler stove working. This has been the stumbling block for why I havent changed my system over. You could I suppose use some zone valves and put them on a timer so you could still use the store but it starts to get too complicated for me!



Title: Re: adding central heating to the boiler stove question
Post by: mr_magicfingers on June 11, 2020, 04:23:05 PM
Good to know someone else has a similar system. Having hardly used the rads through the store over the past few years, I'm less worried about disconnecting them from the system, the office/workroom would only really be used during the day/evening so having to throw logs on the fire is less onerous than it might otherwise be. Being in Devon, we don't get the deep cold that you get further north, just an awful lot of rain :)

One thing about the rads is that they're one of the safety devices for the system, if the store overheats, then the pump will kick in and circulate some water to drop the store temperature. There's other safeties as well so removing that wouldn't be a safety issue as there's always the drench on the store for emergencies.

I thought about combining the systems but then, as you mention, you're into zoning valves etc and I really like the simplicity of this system as it currently stands. Even during power cuts I can have heating, hot water and even cook on the stoves as I often do with stews and soups when the stoves are running during the winter.


Title: Re: adding central heating to the boiler stove question
Post by: Mostie on June 11, 2020, 04:40:16 PM
Mine is almost to that drawing, except the returns are crossed over


Title: Re: adding central heating to the boiler stove question
Post by: mr smith on July 13, 2020, 05:35:38 PM
I run a house with a dry system and a house with a stove supplying 9 rads and a water tank. The house with the dry system works better inmo but works with air vents to heat the upstairs rooms so there is a lack of privacy.

So If you can I would just get better circulation trough the house and keep running a dry stove.


Title: Re: adding central heating to the boiler stove question
Post by: renewablejohn on July 14, 2020, 08:40:48 AM
Our Dunsley Yorkshire works like this with the hot water tank on gravity feed and the 7 radiators on a pump. Pump only used in colder weather or when we over cook the hot water tank. Will soon be modified with UFH going in to replace 4 of the radiators.


Title: Re: adding central heating to the boiler stove question
Post by: mr_magicfingers on July 15, 2020, 01:32:21 PM
I run a house with a dry system and a house with a stove supplying 9 rads and a water tank. The house with the dry system works better inmo but works with air vents to heat the upstairs rooms so there is a lack of privacy.

So If you can I would just get better circulation trough the house and keep running a dry stove.

Not so easy to do with a 250 year old cottage that has 3' thick stone walls.


Title: Re: adding central heating to the boiler stove question
Post by: mr_magicfingers on July 15, 2020, 01:33:00 PM
Our Dunsley Yorkshire works like this with the hot water tank on gravity feed and the 7 radiators on a pump. Pump only used in colder weather or when we over cook the hot water tank. Will soon be modified with UFH going in to replace 4 of the radiators.

Thanks John, that's great to know. Looks like the easiest and cheapest way to get what we need.


Title: Re: adding central heating to the boiler stove question
Post by: mr smith on July 25, 2020, 02:56:39 PM
I run a house with a dry system and a house with a stove supplying 9 rads and a water tank. The house with the dry system works better inmo but works with air vents to heat the upstairs rooms so there is a lack of privacy.

So If you can I would just get better circulation trough the house and keep running a dry stove.

Not so easy to do with a 250 year old cottage that has 3' thick stone walls.

Not easy but possible as we have 3' granite walls. We just vented through floorboards to let heat flood upstairs. The odd room that could not be reached has a top up electric radiator only needed when low 10's outside.