There is a particular week every September when the heating goes back on across Ireland for the first time in months. Boilers that have sat idle since May fire up, stoves get their first load of the year, and chimneys that have quietly housed a jackdaw’s nest since spring are asked to do their job again. It is also one of the riskiest weeks of the year for carbon monoxide.
On average, six people in Ireland die every year from unintentional carbon monoxide poisoning. That figure does not begin to capture the much larger group who spend a whole winter with headaches, tiredness and a fuzzy head that nobody ever thinks to connect to the boiler.
TL;DR
- Carbon monoxide (CO) kills about six people a year in Ireland and is produced by any fuel that burns: gas, oil, coal, turf and wood
- The risk rises with age for practical reasons: more hours spent at home, older heating systems, and heart or lung conditions that leave less margin
- CO symptoms (headache, dizziness, weakness, confusion) are routinely written off as a virus, a new tablet or “just getting older”
- Insulation and draught-proofing can increase CO risk if ventilation is reduced around an open-flued appliance, which is why blocked wall vents and capped chimneys matter
- Buy an audible alarm marked EN 50291 with an end-of-life indicator, have appliances serviced annually by a Registered Gas Installer, and if the alarm sounds, get out and ring 1800 20 50 50
Where it comes from
Carbon monoxide is produced whenever a fuel burns without enough oxygen to burn cleanly: gas, oil, coal, turf, wood and petrol can all produce it. The gas is colourless, odourless and tasteless, which is the entire problem. It binds to haemoglobin far more readily than oxygen does, so your blood quietly carries less oxygen around while the experience, from the inside, feels like ordinary tiredness.
In an Irish home the usual sources are familiar ones: a boiler that has not been serviced in years, a blocked or cracked flue, an unswept chimney, a stove fitted without adequate ventilation, or a gas cooker pressed into service to take the chill off a kitchen.
Why the risk is different after 60
You are home more. Retirement, part-time hours or reduced mobility all mean more of the day spent inside whatever the house is doing. Exposure depends on concentration and time, and the time side of that equation goes up.
Heart and lung conditions leave less margin. CO reduces how much oxygen your blood delivers, and if your coronary arteries are already narrowed there is less room to absorb that. A small early study of ten patients with ischaemic heart disease, published in the Annals of Internal Medicine, found that low-level CO exposure shortened the time it took for angina to come on during exercise, at concentrations well below the level that would set off an alarm.
The symptoms get filed under ageing. Headache, dizziness, weakness, nausea and confusion in a 40-year-old prompt questions. In someone of 75 they tend to get put down to age, a virus or a new tablet. CO poisoning is well documented as being mistaken for migraine, stroke, viral illness and food poisoning.
The retrofit paradox
Here is the part that rarely makes it into the grant brochure. Ireland’s national push to upgrade home energy efficiency is genuinely good news, because cold homes do real damage to health. But sealing a house changes how air moves through it, and where there is an open-flued appliance, that matters enormously.
An open-flued appliance (an older gas or oil boiler, an open fire, many stoves) draws the air it needs for combustion from the room itself. Take that air away by draught-proofing, capping a chimney or covering over wall vents, and the appliance can starve, burn incompletely and spill CO back into the room.
The standards understand this perfectly well: SEAI’s technical guidance requires permanent ventilation in any room with a fixed open-flued appliance where wall insulation is being installed, and grant-scheme contractors must follow NSAI’s S.R. 54, the Irish code of practice for energy-efficient retrofit. The gap is in what happens afterwards: a vent stuffed with a cloth because the room feels draughty, a chimney capped during a redecoration, a new stove fitted without the vent that should have gone in beside it. If you have had work done in recent years, walk around and count your vents. That annoying whistle of cold air is doing a job.
The pattern that gives it away
Any single symptom is too vague to act on. The pattern is not:
- Symptoms ease when you are out of the house and come back when you return
- More than one person in the household feels the same way
- The pet is off form too, particularly birds and small animals
- It started when the heating went on, or after work was done on the house
- Sooty or yellow-brown staining around an appliance, a lazy yellow flame where it should be crisp and blue, or unusual condensation on the windows
The alarm
Research commissioned by Gas Networks Ireland found that three in four Irish households now own a CO alarm. That still leaves a great many homes with none, and plenty more with one that expired years ago without anybody noticing.
The NSAI recommends a four-step check before you buy. The alarm should be audible rather than one of the passive colour-change patches, which cannot wake a sleeping person. It should be marked EN 50291, carry a CE mark, and have an end-of-life indicator, which is not the same thing as a fault indicator.
Fit one in any room with a fuel-burning appliance and one where you sleep. Press the test button monthly. Most alarms have a working life of seven to ten years, so check the date on yours. And a CO alarm is not a smoke alarm: you need both.
Who is actually allowed to touch your boiler
Domestic gas work in Ireland must be done by a Registered Gas Installer. The Energy (Miscellaneous Provisions) Act 2006 makes it an offence for anyone else to carry out gas work, and an RGI is legally required to issue a Declaration of Conformance for the job. You can check somebody’s registration at rgi.ie rather than taking a business card on trust. For oil-fired systems, look for OFTEC certification instead, and chimneys serving solid fuel should be swept at least once a year.
If the alarm sounds
Do not go hunting for the source. In order:
- Open doors and windows
- Turn the appliance off, if you can do that safely
- Get everyone out into fresh air
- From outside, ring Gas Networks Ireland’s 24-hour emergency line on 1800 20 50 50, which works no matter who supplies your gas. If anyone is unwell, drowsy or unconscious, ring 999 or 112
- Do not use the appliance again until an RGI, or an OFTEC-registered technician for oil, has checked it
For non-urgent questions, there is a carbon monoxide information line on 1800 89 89 89.
Two things worth doing this month
First, if you go to your GP or an emergency department with headaches, dizziness and nausea and you have any suspicion about the heating, say the words out loud. It changes what gets tested and how quickly, and CO clears from the blood within hours of breathing fresh air, so a delayed test can look reassuring even when the exposure was real.
Second, if you are 66 or over, ask your gas supplier to add you to the Special Services Register. It brings protection from disconnection between 1 October and 31 March, priority reconnection, and advance notice of planned interruptions. Gas Networks Ireland runs an age-friendly customer line on 1800 628 427.
At Críonna Health we keep arriving at the same conclusion: a great deal of what protects health in later life is not medical at all. A serviced boiler, an unblocked vent and an alarm with a date you have actually checked will do more for your winter than most things you could buy in a pharmacy. It is a far easier afternoon’s work to find in September than in January.
This article is for general information and is not a substitute for advice from your GP or a qualified heating professional.
📷 Photo by Annie Spratt on Unsplash
