stove with a back boiler on a closed gas central heating system?

gomamochi1

Hi all, We have a recently refurbished gaff with a Veissman gas boiler in the attic. I understand from the plumber its a closed system. I installed myself two stoves one in the front room 8kw multi fuel stove and a 5 kw multi fuel in the kitchen/ living room.
Lovely heat out of both especially with the drop in degrees recently however I always was keen on a back boiler version but the plumber put me off saying you need an elaborate system costing 500 euros. any suggestions? cheers

cikearney

You'll need a new dual coil cylinder, with this you can heat the water with the back boiler.

Pipework from the stove to the cylinder, it'll need an f&e and a pump and safety features, €500 mightn't be a bad price after all

shane0007

You must change from sealed system to open vented. The boiler may not work if the head is not high enough to energise the pressure switch in the boiler. This is an integral safety feature of the boiler which should not be made inoperable,
Secondly, I personally would not combine solid fuel with a gas boiler. Solid fuel will always lead to a dirtier system which will contaminate the gas boiler heat exchanger as they are far more restrictive than that of an oil boilers.
As cikearney says, you will also have to change the DHW cylinder to a dual coil one, so €500 will most certainly not cover the required works to be done correctly.

Pete67

If you add a dual coil cylinder, you can keep the sealed system completely separate from the back boiler, but you will also need to add a new F&E tank for the stove and probably an additional separate heat sink radiator on a pumped circuit as well so that you can prevent the stove from boiling when the hot water cylinder is fully heated. This will get you hot water from the stove, but will not be capable of heating the existing radiators.