Carbon monoxide leakage is the biggest problem with an unchecked fireplace, said director of Flue Line Solutions and former cocktail bar owner Mike Byrne, dubbing it a “silent killer” due to its lack of smell, taste, and colour.
He said: “Over a long period of time, carbon monoxide can build up in the blood, and the body can't naturally disperse that. So that would be immediate danger to people.”
The situation in a pub with open air conditioning units and an open fireplace could be a greater hazard. Byrne gives an example from a few years back to highlight this.
He said: “It was a pub, and it was in the Midlands. And they had a patron who had been going there for years and years and years, and he had his favourite spot. And that was at a bar by the fireplace.”
The problems came when a new extraction unit was installed: “What they didn't think about is how that extraction unit could affect how well the appliance and the chimney would work,” Byrne said.
He continued: “And basically what happened is, the extraction unit was pulling a lot of the advantageous air throughout the pump, and causing the chimney to lose its ability to be able to naturally draw the combustion gases.
“So unfortunately, for this old boy, the carbon monoxide fumes would go past him and go through to the kitchen and then get extracted that way.
“And if you can imagine over a long period of time, this built up to a point where one day they thought the old the old boy was sleeping and unfortunately he passed away from poisonous combustion gases.”
When asked the best ways to check a fireplace is working correctly, Byrne said: “The simplest way is to have your chimney swept and smoke tested an appliance service every six to 12 months.”
He added: “The person on site, if they're competent, they should also be looking into the other factors, […] such as has a new air conditioning unit being installed.
“It's extraction fans, that kind of thing, you know, anything that will affect airflow within the site could affect how well their appliance is going to work.
“[…] Another simple step would be to put a carbon monoxide alarm or detector close to the appliance and chimney.”
Byrne said: “If you're a new owner to a pub, or if you're a new manager or general manager, just have a look see if the appliance has been checked: is there any documentation recently or at least within the last 12 months to say so?
“If you don't, then don't use the appliance, and go get an engineer out to have a look at it.
“[…] Anything to do with gas, use a gas safe engineer who is competent in fireplaces and stoves, and that kind of thing.”
Byrne said that servicing a fireplace, which costs £95 to £150, is “completely” worth it.