Dramatic changes in personality, mood swings and depression could all be a sign you need to get your gas boiler serviced. 

Carbon monoxide is known as the silent killer,  but low level poisoning can lead to symptoms that aren't always as obvious as dizzy spells and nausea -  and mental health and behavioural issues may also be signals. 

"Depression, agitation, confusion and irrational behaviour can all be indicative that there is a low level leak," says boiler safety expert Ranjen Gohri, from Boiler Breakdown company 24/7 Home Rescue. ​

He's now urging anyone whose personality or mood has changed to consider a CO leak as a possible cause and have their boiler urgently checked.

"Emotions going awry and unusual behaviour often put down to something else entirely, could be indicators of a CO leak so always get your boiler checked out,"  Ranjen urges.

"More common signs are headache, tiredness, dizzy spells, shortness of breath and nausea. But they may not always present themselves," he adds.  Known as the silent killer, carbon monoxide is a colourless, odourless, toxic flammable gas which is formed by the incomplete combustion of carbon. 

High levels of exposure can cause death rapidly, but low levels can gradually take their toll without the victim suspecting CO emissions are to blame.  It affects white matter and a part of the central brain called the basal ganglia which is associated with a variety of movements, habit learning, cognition and emotions.

Disrupting this part of the brain can induce the unusual behaviour. This can range from random out of character acts to different emotional waves. "Carbon monoxide poisoning could cause a person to behave in a way they've never behaved before," explains Ranjen.

"They might make an extravagant purchase or behave out of sorts.  "These sort of acts are normally blamed on stress, over-working, clinical depression - but it could be down to a carbon monoxide leak." Symptoms intensify the longer you continue to inhale CO, warns Ranjen. "Long-term exposure to low levels means temperament can get worse. A person may snap for no reason. 

"They may also find themselves struggling to make decisions and find it hard to concentrate. "Over time, physical symptoms will develop, this is when it can get fatal." Ranjen stresses that buying carbon monoxide detectors is the wisest move you'll ever make.

"In a nutshell, they're worth their weight in gold. They save lives."  Around 50 Brits die from carbon monoxide poisoning each year. A further 4,000 make medical visits, according to the Department of Health.

Ranjen's concerns are backed up by brain injury charity Headway who say low-level CO poisoning from faulty boilers may not be recognised: 




Meanwhile Ranjen stresses it is vital boilers are fitted by a Gas Safe registered engineer and serviced regularly.   “There are some telltale signs that your boiler might pose a carbon monoxide problem," he explains.   “Your pilot light might be blowing out frequently, or changing colour from blue to yellow.

“If you’ve got black stains near your boiler, or on the ceiling above it, that’s also a sign that CO might be escaping from your flue.

“Meanwhile if you’ve got heavy condensation on your windows, that’s another sign that gases aren’t be properly vented out of your home - and could be filling rooms  with CO.

“And if you’ve got any doubts in your mind whatsoever, seek immediate help. Badly fitted and poorly maintained boilers - as well as ovens and other gas appliances - can kill within minutes. Don’t run the risk.”

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