With the rising cost of Oil and the environmental impact of burning fossil Heating Oil (Kerosene 28) and the fact that we had several acres of woodland we thought that we could reduce our carbon foot print and save money (Heating Oil  was costing us about £1600 a year).

  We bought a wood burner that could provide central heating and hot water - we calculated that we would need a boiler capable of providing about 21KW or 85,000 BTU. We wanted the wood burner to run along side the Oil fired boiler so in the mornings the Oil boiler would start automatically and the house would be warm for us to get up and dressed!  And when we are up we could light the wood burner and feed it with wood until about 10 O'clock at night.

 We have found so far that the wood burner needs fuel at least every half an hour until the radiators or hot water have reached the required temperature, then the wood burner thermostat (yep our wood burner does have a thermostat) can be turned down and the wood lasts about an hour before it needs feeding.

   A normal wood burner is not "Controlled" heat source, that means it can't have a timer or programmer to switch it on & off.

  So you have to manually light it and feed it with wood. There are Wood boilers which run on wood pellets  and theses often have timer/programmer controls but these are very expensive and need a whole outbuilding to themselves - and further more they cant be low carbon because their fuel still has to be made and transported.

   To connect the wood boiler into the existing system requires a good plumber who understands solid fuel appliances and a good electrician, I was lucky and found both. The plumber who installed the pipe work and Dunnsley Neutralizer was Nikk of Climate Solutions Southwest they also install solar heating. And the electrial connections which, were a lot more complicated than I first thought!  were installed by Mark of Exe Electrical  - Diagrams are on the Dunnsley Heat website.

 The problem with linking boilers together is that one boiler when is lit it will  supply the second boiler with hot water when it is not in operation, therefore wasting a lot of heat/energy.

 The Dunnsley web site contains a lot of useful info on wood burners and linking to radiators and pipe work diagrams and the electrical drawings.

Update: to date we have had to replace the Sunvic valve twice because on several occasions in sticks in radiator supply position, requiring a gentle tap on the case to release it, so it will supply hot water to the hot water cylinder. You can hear the spring opening the valve, which this them closes a contact that starts the boiler.