pressurised central heating system versus unpressurised

[xt40]

ive an existing pressurised oil ch system with a mix of rads and ufh to which i want to add a wood burner. for safety reasons this is not such a simple operation and afaik the 2 choices i have are
1 change to a twin coil cylinder and use the wood burner to heat the water and bathroom rad on a seperate circuit - expensive and awkward.
2 plug in to existing circuit and add a second tank in the attic to depressurize the ch system - easy and cheap.
is anyone aware of any disadvanteges of or issues with an unpressurised system

 

[davidoco]

Re: pressurised ch versus unpressurised

2 plug in to existing circuit and add a second tank in the attic to depressurize the ch system - easy and cheap.

You're still going to need the rad in the bathroom (or other location) as a heat leak in the event that all rads/uf are satisfied and hot water temp has been reached in cylinder.

Also when you have only your wood burner going you have the problem of the water running through the gas/oil burner creating a heat leak in itself - but this could be overcome with injector valves and motorised valves - this is something that was done in the past but it is unlikely you will find a plumber to do it nowadays that we are so litigious.

To be on the safe side have a look at something relatively cheap and cheerful such as the Dunsley [broken link removed]