Wood burner with back boiler and Oil fired central heating

[Daviddonk]

Hi i currently have a large wood burner fitted with a back boiler that heats the hot water and a single rad on the landing via gravity flow and return. I also have oil fired central heating throughout the house. The hot water tank is double coiled one for oil boiler and the 2nd for wood burner.
Is it A: possible to connect the two systems together so that when the wood burner is going the oil boiler is off, and as wood burner cools down oil takes over.

or B: better to add a couple rads to wood burner and a pump and let them run independantly.

Which would be cheaper to do and what would you recommend?

Cheers
Dave

 

[dontknowitall]

From what I understand you already have A!!

Just in case you don't know (and plenty of people don't) your hot water cylinder is a large copper tank. Cold water is fed at the bottom and hot water comes out of the top. The two "tappings" in the side are Flow (top) and Return (bottom). If your tank has four of these tappings then the top pair will be the connected to your oil boiler (flow and return) and the bottom pair will be connected to the back boiler of your wood burner. Finally, you've probably got a larger tapping in the top which is the immersion heater (very similar to a kettle element) so if you run out of wood and the boiler stops working, then you can use electricity to heat your hot water.

The radiator connected to the wood burner is a safety issue and releases heat to the atmosphere in case things go wrong. If you attach more radiators you'll never have good heat from any of them. If you want more radiators you a) need to make sure the boiler is larger enough and b) ensure they're connected to the boiler heating circuit.

 

[justlead1]

Hi. Although this arrangement can be installed it can cause problems when controls, stat's etc break down. I have been called out to a couple of time. Finding that the wood burner boiler acts as a rad when the oil unit was working. Spending hours trying to work out how the control are wired and react with what. Then finding a safe and Eco solution to the problem. (The installers on the missing list)
Personally proposal "B" is the way i would go. Good Luck

 

[Daviddonk]

Yeah i was thinking option B was the better one. Would any one know an approx cost we live in a 2 bedroomed house and was thinking of a rad in the kitchen and bathroom. These are the only roooms that feel the cold with just the wood burner going. I havent used the oil boiler since new year. My tank is empty and not paying 60ppl to fill it up.