To remove or not to remove

[Ian Stirling]

Back boilers are not designed to work at fire temps, and once you heat the front up to 600C (or whatever) with a nice toasty fire, normally the back would be at 100C, but drained it would be quite hot indeed, and possibly a fire risk, depending on design. Even best case, it's probably not going to last long.

You could incorporate the output of the back boiler into a hot-water cylinder, with two coils, one of which is a high rate coil. Input to the combi would go through the high rate coil.

There is probably a proper term for this system.

(I have no knowledge of if most combis can accept high input temperature, this may be a poor suggestion)

Alternatively you could stick a radiator in the loft, fed from the back boiler.

Removal may be the simpler option.

[Ian Stirling]

Back boilers are not designed to work at fire temps, and once you heat the front up to 600C (or whatever) with a nice toasty fire, normally the back would be at 100C, but drained it would be quite hot indeed, and possibly a fire risk, depending on design. Even best case, it's probably not going to last long.

You could incorporate the output of the back boiler into a hot-water cylinder, with two coils, one of which is a high rate coil. Input to the combi would go through the high rate coil.

There is probably a proper term for this system.

(I have no knowledge of if most combis can accept high input temperature, this may be a poor suggestion)

Alternatively you could stick a radiator in the loft, fed from the back boiler.

Removal may be the simpler option.

[Shona Honeyman]

Opinions please

I am having an old traditional central heating system replaced with a combi-condensing system.

My difficulty is that I keep getting conflicting advice from would be installers regarding a Parkray coal fire back-boiler.

Obviously, there is no way of incorporating the back-boiler within the new system, but can it be simply drained and left to vent hot air into the loft, or will it burn through and be a fire risk? How difficult (costly) is full removal likely to be?

David

[N. Thornton]

makes no sense to dump heat into the loft, dump it in a rad downstairs. Pump on a thermostat would only run when water warm. What else can you do with an erratic temp hot supply? Preheat the feed to the hot water tank. Both worthwhile uses, both will cut fuel bill.

Another poss option is to cut open the backboiler and fit vents so the fire back produces hot air that comes into the room. Have played with such a setup, worked very well indeed.

Regards, NT

[jacob]

Shouldn't be difficult to remove - just break it out with big hammer, cold chisels etc. Rebuild with rubble in spaces and fire bricks at front, but you need to know about fireback/throat detail design. cheers

Jacob