Back Boiler

[dsnd_medic]

A couple of years ago I put oil central heating in my house. I live in a single story cottage and have run all the piping up and through the loft as the hot water tank was there and the cottage floor is made from cement. However as we have a coal fire going nearly everyday in winter I thought that if I fitted a wrap around back boiler into the hearth, then it would save me a fortune in oil costs. I now have a good 2nd hand back boiler but have been told it won't be as easy as I thought to plumb it into my existing system. I have an open system, ie not pressurised, My flow and return pipes are 22mm with 15mm pipes being used to supply all the radiators. Some people say it will work fine if I just attach the back boiler to the flow and return others say I will have major problems regulating and dissapating the heat. Will I still need the circulating pump when the backboiler is being used or can I rely on purely convection to circulate the water.

Am I making a big mistake or is it a feasable idea......any comments or tips would be greatly appreciated

Thanks in advance

Andy

[John]

google Dunsley Neutraliser

[Doctor Drivel]

Best use a thermal store. Look at

for explanation.

[Rick]

Andy

If you boil the water in the back boiler you are in big trouble, you will have lots of gas to get out of the system, and it has to get throught the pipes and out of the expansion pipe at the top. Boliing the water makes a terrbile racket.

We joined our back boiler in with a dunsly baxter neutraliser. When the fire was on, we flick a switch that pumps the fire water into the neutraliser, and then the rads / hot water take the heat away. I have since junked this thing. When the fire is on, the gas boiler goes off. I made a box of tricks with some relays from maplins.

My new house, will have no gas / oil boiler, and two wood fires. I have since learnt that it can be done with gravity, but thats hard in a bungalow. I then learnt that the pumps really need a UPS system - you don't want that water boiling. if you have no UPS, a bucket of water on the fire when the leccie fails is just as good.

One idea is to use a thermal store, so you heat that with the fire, and its so big it will take all the heat you can make in 8 hours of wood burning. You then take the heat out for rads hot water etc. The oil or electric can be used as top up, as can solar etc ...... This is what I will do.

So it is feasable, but is not obviously simple.

Rick