Can anyone tell me a bit about this old back boiler? Can I safely use the fireplace?

[Mike Barnard]

This fireplace hasn't seen coal since 20 years ago. We would like to put a fire in again, but wonder if there could be a problem with the old back boiler which is still in place.

Logically, the only way gases could get out (apart from a leaking flue which is a seperate question and check to be carried out) would be if there was a leak inside the boiler and gasses got into the copper. As it won't have any water in it, could the pipework be damaged by heat?

Any pointer to websited with more info would be gratefully recieved. Yes, I have googled.

Thanks for any info you may be able to pass.

Mike.

[Dave Plowman (News)]

I'd think you could melt the copper with a roaring fire if there's no water in it.

[js.b1]

Can not quite see what I am looking at, but...

Is it still plumbed in to an immersion tank, with water in it?

- If there is water in it and the whole lot freezes (cold air descends) you can actually defrost the front half with a fire, but not the rest and the boiling water can result in an explosion. It is rare, but has happened - bungalows seem to be more vulnerable perhaps re smaller chimney run when left empty.

- If there is no water in it, the fumes from the fire can be drawn somewhere else - creating secondary fire or carbon monoxide poisoning. This is particularly dangerous with open flue gas fires which can create quite a bit of CO which can wander elsewhere, but other materials burnt in a fireplace are not exempt from this fatal scenario.

Check the chimney itself is intact and fit for usage.

- If there is a second upstairs chimney are the feathers ok (bricks separating them), otherwise you can get gases & heat migrating.

- Likewise is the chimney fit for high temperatures created by burning coal and that ubiquitous bit of wood that gets thrown on there, because just about all the coal burners used to get wood in them if coal had not been delivered. Failures in internal structure can result in joists being set on fire.

An empty back boiler should be filled with sand completely, ideally removed. Do not leave open pipework because products of combustion can go somewhere else. Think the HSE has something to say on this.

[Peter Parry]

The usual solution was to remove the pipework,fill the cast iron back boiler with dry sand and plug the holes with fire cement. You then drilled several holes from the fire side through the upper part of the cast iron into the water jacket.

The boiler _must not_ be sealed otherwise there is a risk of explosion through expansion of the air in it.

essential reading as well as instructions on what to do.

what can happen if you don't.

[The Natural Philosopher]

I installed a log burner that had pipes for water. I simply left them disconnected. Didn't bother to sand fill. It is OK as I don't think the heat exchanger was cast - its pure steel. Even if they do crack its unlikely to put fumes in the room anyway. Chimney+fire will result in negative pressure inside.

The sand is best practice - spreads the heat most evenly - but IME its not essential.

Not sealing the pipes is the mandatory element .. bound to get a bit of condensation inside and without the expansion capability, BOOM.

[Mike Barnard]

Good morning all.

Thanks for that, especially the H&S link about remaing water building up steam. We've decided to pull the lot out. Now I need links on how to rebuild a proper fireplace! :)

[The Natural Philosopher]

That is not hard..but the chimney and flue are.

The key is that the aperture of the fire should be no more than 5-7 times the cross section of the flue, and its NOT a good idea to have a flat topped fire box with a hole in it - you need a smoke chamber above the lintel for an open fire.

If that hearth was designed for a stove, you may need a smoke hood if you are going open hearth

If you go for a stove, then you should probably line the flue.

If the fire has been out of action for years, please do a smoke test and look in the loft for signs of busted mortar joints: round here with old flues and timber frames,, after electrical this is the most common place for fires to start. Consider a loft mounted smoke alarm as well.

[A.Lee]

I did just the same when we moved here. Ours was a large copper cylinder set into the fireplace. Jemmy it out, (and weigh it in), then you fill in the holes with firebricks/bits of fire bricks with lime cement. You then put you fireback into position, it may need lifting up etc, then fill the back, again with a mix of firebrick, or, plain lime cement/mortar.I think there may have been some refractory insulation in there too. Let that go off, then fill all gaps with mortar. There may be bits I've missed as it was 15 years ago when I did mine. I got a book from the library that showed exactly how it was done (surely there is a step by step website now?), and it has lasted well, the fireback has started to wear out a little at the bottom, otherwise, the chimney sweep says it is all good.

Alan.

[hugh]

In message , Mike Barnard writes

Very wise decision.

[js.b1]