gravity flow back boiler

[Dhugael Iliff]

I'm hoping to have a back boiler woodburner installed, which can work to heat cylinder by gravity even when no power (still happens!). Looking at other threads, I fear that pumps MUST now be installed, so is this not now allowed?

 

[joni os]

Older heating systems with hot water by gravity circulation and pumped central heating are no longer considered efficient. However, design for back boiler off woodburner would need to circulate by gravity in event of pump failure.Position of DHW cylinder,size of flow and return pipework, heat resistant F&E tank, heat sink.are all necessary considerations.Properly designed the system should work with no power to the pump. ( or even with pump removed).

 

[Dhugael Iliff]

Thanks, that gives me hope! Most grateful!

 

[wattsie1987]

Look at thermal store cylinders providing you have sufficient mains pipework.

 

[chris watkins]

What type of cylinder are you thinking of, not un-vented I hope ?

What are you going to use to heat the hot water in the summer ?

As above, a thermal store can be a good option.

 

[Dhugael Iliff]

I currently have a small uninsulated copper tank, fed from cold tank in loft, with expansion/overflow up into cold tank. Advice from local man was I need a mains pressure hot cylinder, with pressure release valve to outside- is this what is called Unvented? (mains Cold pressure is adequate). Thanks.

 

[joni os]

Don't mix unvented cylinder and solid fuel boiler. A thermal store is a different animal which delivers hot water at mains pressure, like an unvented cylinder, but is compatible with solid fuel if correctly positioned.