Back boiler & oil boiler to twin copper cylinder

[sheen]

Hi,
A friend of mine wants to to join a back boiler and an oil boiler to a twin coil copper cylinder and wants both of them to work a central heating system. Can anyone give me any ideas how best to do this.
Thanks

[got_nailed]

Let me get this right you have 2 boilers and they want to use one or the other at different times.

If there both closed systems you just need to put in 2 check valves and use 2 pumps. This would be coming off the hot side of the boilers. The return would go to witch ever one was sucking the water. This would work the same on a open loop system.

You could use Water to Water Plate Heat Exchanger. But that would also be fun to describe. But it would not be too hard to draw out. The heat exchanger IMOP is not the way to go.

[sheen]

Thanks for the info. i will pass it on to him in a couple of days, and if he needs to know more, I will add another thread.
Sheen