Old (solid fuel) back boiler

[BTP]

Hi, I've been asked to provide a quote for a customer who wants central heating. Currently the property has only a conventional coal fire with a back boiler. My plan is to install combi. So drain down the existing gravity feed direct hot water system and remove the hot water cylinder. The customer may want to retain the coal fire. My question - can I safely leave the back boiler in situ? I.e. Behind the coal fire.

 

[stani]

No

 

[Best]

I dilthered a bit on a reply because I see loads of boilers left behind open fires that have a fire occasionly in them. Never seen a problem happening if the boiler is fully drained (normally a hole with steel drill bit drilled near bottom of fire boiler to drain it). But you risk a slight chance of fumes passing through, or something catching fire.

 

[BTP]

No

Thank you Stani

 

[BTP]

I dilthered a bit on a reply because I see loads of boilers left behind open fires that have a fire occasionly in them. Never seen a problem happening if the boiler is fully drained (normally a hole with steel drill bit drilled near bottom of fire boiler to drain it). But you risk a slight chance of fumes passing through, or something catching fire.

Thanks for that, I hadn't thought of that. With the water drained and the vessel vented there can't be any risk of explosion. Do you think Co could find a way into the room?

 

[stani]

The fire and back boiler are a combined unit, when they were first fitted, there weren't really any manufacturers instructions to follow but one of the main things was, don't run the fire until you have water in the boiler.
With no water in the boiler you will quickly burn through the heat exchanger, this will allow POC to enter the hex pass up the cut pipes and find there way into whichever room you cut the pipes in.
If you empty the hex and seal the pipes any water left in will turn to steam and cause a massive rupturing of the hex.
So, really no is the answer, take fire out and put in an electric fire.

 

[BTP]

Thank you Stani and Best. You are both spot on. Your responses prompted me to do a little more digging. I found that the HSE had. issued an alert in 2008. The alert talks about the issues you both identified; in short as you both advised the unit has to come out. Thanks again for your help and guidance.

 

[stani]

BTP
Thanks for the reply and update, much appreciated