Emergency crews were called to a property near Wargrave Road, Newton-le-Willows, shortly before 8.30pm last Thursday (February 14).
On arrival, paramedics became concerned about the presence of carbon monoxide and called for backup from the fire brigade.
The occupier, an elderly man, was taken to Whiston Hospital for treatment, however the hospital was not placed on standby prior to his arrival – suggesting his condition was not serious.
Firefighters donned breathing apparatus and entered the property with ToxiRAE monitoring equipment, to detect the levels of carbon monoxide.
They used a fan to ventilate the property before checking the carbon monoxide levels at neighbouring properties.
Watch manager Mike Costello, from St Helens Fire Station, said: “This was a solid fuel, free-standing boiler with a suspected defective flue causing very high levels of carbon monoxide in the property.
“Our equipment showed a level of 380 CO parts per million, which is a very high reading. At between 400 to 600 carbon monoxide parts per million you could lose consciousness and vomit.
“Fortunately, in this circumstance, because it was a solid fuel fire, the occupiers could smell something unusual, as there were a range of gases being let off when the fuel was burnt. CO is odourless but in this case the smell of other gases alerted the occupiers.”
Mr Costello added: “There was no CO detector in the premises. We advise people get all gas and fuel burning appliances checked by a registered engineer each year and advise people fit CO detectors. This incident shows that it is not just gas appliances that can result in the release of carbon monoxide in your home.”
A police spokesman confirmed that officers were called to the scene but had ruled out any foul play.
Carbon monoxide is known as the “silent killer”. You can’t see it, taste it or smell it and it can kill quickly without warning.
Is there a silent killer in your home? Go online at: www.silentkiller.co.uk to find out how safe your home is.