Combine GAS C/H with wood boiler hot water

[notfixedit]

I have an existing gravity fed from wood stove hot water system, but no C/H. I have now installed 7 radiators and want to hook these up to a new GAS boiler. I would like to combine the H/W supplies so that when the fire is lit it will switch the supply over to the wood stove. Possibly through a thermostat on the H/W tank. Also as the Gas boiler needs a mains pressure water supply I plan to move the existing expansion tank for the wood stove from the loft to the downstairs airing cupboard (site of H/W tank and GAS boiler and use one of the existing feed pipes to supply the GAS boiler with necessary mains pressure water supply. This would save extra plumbing work and possible floor or ceiling removal to gain access. I don't see any problems but would appreciate any advice or comments. Eddy

 

[Agile]

I would say that what you need is beyond the scope of a DIY design.

The obvious advice is to get a competent engineer to at least design the system even if you are going to fit it yourself.

Tony

 

[Corgigrouch]

Why do you feel that the gas boiler would need a mains pressure water supply..?

 

[stardanny]

Why do you feel that the gas boiler would need a mains pressure water supply..?

I think the op want a gas combi boiler. He want to combine hot water from cylinder and from combi with a sort of switch. That what I am thinking what he mean.

Op, it is best to leave expansion tank in loft and use open vent gas boiler and special tank that sit under cylinder ( can't remember what it call ) so a fully pumped gas boiler and gravity wood stove can work together for radaitors.

Daniel.

 

[picasso]

Google thermal stores or dunsley neutralizers but as said its outside the scope of the diyer.

 

[Corgigrouch]

Danny, I had suspected that but didn't want to do my usual trick of jumping to conclusions...

I too would suggest that the combi SF link up is the most awkward and complicated way to go... I like to go the thermal store route usually but if the customer already has a cylinder in good nick then a Dunsley neutraliser is your friend....

This kind of job is usually beyond the abillity of all but the most dedicated and able DIYer

 

[notfixedit]

Why do you feel that the gas boiler would need a mains pressure water supply..?

I understood that combi Boilers are designed to work with a pressurized water supply. Am I wrong?