One concern I take very seriously is carbon monoxide safety. Even well maintained boilers can become a hazard if ventilation is poor or components fail. In this post I want to share my frontline experience diagnosing and preventing carbon monoxide leaks in Croydon properties, and explain why regular checks and simple upgrades can make all the difference.
What Is Carbon Monoxide and Why Is It Dangerous
Carbon monoxide is an invisible, odourless, and tasteless gas produced by incomplete combustion. Even small leaks can cause symptoms like headaches or dizziness. High levels can be fatal in minutes. As boilers age or flues become blocked, residents may unknowingly be exposed, putting families at risk.
How CO Emissions Occur in Boilers
CO is formed when there is an imbalance in gas to air mix. Faulty burner jets, blocked flues, fan issues or degraded seals can all cause CO presence in flue gases and potentially allow leaks into indoor air.
Symptoms and Long Term Effects
Short term exposure leads to headache nausea breathlessness and confusion. Chronic exposure might present as constant tiredness or chest pain. It mimics flu or tiredness which is why many miss the link to their boiler. In Croydon I have seen £30 readers relaying symptoms until a detector unmasked the real cause.
Why Croydon Boiler Installations Need Extra Vigilance
Croydon’s diverse housing stock—from modern apartments to old terrace houses—brings unique challenges. Sloping roofs shared flue terminals and packed loft spaces can trap gas. I’ll explain what I look out for on site.
Close Proximity Flues and Shared Chimneys
In older terraces shared chimneys may not have been lined properly when boilers were upgraded. I regularly find unsealed flue connections or gaps behind boiler backs where CO can escape into heated rooms.
Blocked Flue Outlets in Backyards
Garden clutter or bird nesting can block flue outlets easily. Even small nests reduce airflow and push CO back down the terminal pipe leading to internal leaks.
Ventilation Issues in Converted Lofts
Loft conversions often seal in pipework and boilers requiring updated ventilation. I’ve opened 1930s lofts where old pipes met compact boilers with no adequate air supply—dangerous by today’s standards.
Spotting Carbon Monoxide Issues On Service Visits
Here are the key safety checks I perform during routine Croydon boiler service visits:
Flue Gas Test Every Visit
I use a flue gas analyser to measure CO levels at terminal and at burner ports. If readings exceed 50 ppm it triggers immediate investigation even if no fault code is showing.
Visual Inspection of Flue and Ventilation
I trace the flue externally and look for blockages nails rusted clamps or seal gaps. I also ensure there is clear comb construction and air bricks are unobstructed.
Boiler Internal Inspection
Opening the boiler cover I inspect burner housing seals and ventilation slots. Loose screws or gaps can sneakily leak flue gas into the combining casing and then into the room.
CO Alarm Placement Check
I verify that there is a working CO alarm within three metres of the boiler and another near sleeping areas. Many Croydon homes have none at all—this is the easiest life saving step owners can take.
Real Cases I Have Seen in Croydon Thanks to CO Testing
These real life visits show why CO vigilance is crucial:
South Croydon Loft Conversion with ‘Mystery Fatigue’
Homeowners reported feeling tired and nauseous eventually installing a CO alarm which went off when boiler ran. I traced the flue leak to a cracked seal and unsealed top plate in the loft. Fixing the seal and improving loft ventilation solved both the CO and the discomfort.
Old Chimney Shared in Thornton Heath Terrace
A semi detached house had an old chimney meeting a boiler flue on one side only partially lined. CO readings were high. I added new flexible liner and sealed around it to restore full safety.
Bird Nest Blockage in Back Garden Flue
A back garden boiler had very low flow rates I removed a bird nest at the flue outlet. CO readings dropped immediately post fix and heating returned to full output.
How to Reduce CO Risk in Your Croydon Home
If you live in Croydon I recommend you action these key steps:
Install a Certified CO Alarm
Get a ceiling mounted optical CO alarm near your boiler. These cost under £25 and can save lives.
Annual CO Safety Checks
Ask your boiler engineer to perform flue gas tests at every service or repair. Never assume a clean boiler cannot emit CO.
Keep Flue Terminals Clear
Clear leaves branches or rubbish around flue outlets at least monthly. In winter especially when leaves fall over garden feeders.
Ensure Proper Ventilation
Loft conversions conservatory or sealed rooms must have compliance air bricks. Confirm numbers and minimum sizes per regulations.
Upgrade Faulty Boilers
Boilers past their tenth birthday that fail CO tests frequently should be considered for replacement. Modern condensing boilers offer sealed combustion and improved safety margins.
Emergency Response to Suspected CO Leaks
If you suspect CO follow this advice—fast action may save lives:
Turn Off the Boiler Immediately
Isolate the gas at the stop tap or meter and do not restart until an engineer inspects.
Ventilate Windows and Doors
Open windows and doors to disperse gas. Do not use any electrical switch or naked flame in affected rooms.
Evacuate Until Engineer Arrives
Leave the property and wait in fresh air. Call 999 only if someone is unconscious or unwell. Otherwise call Gas Emergency on 0800 111 999 and book a Gas Safe engineer.
Legal Requirements for CO Safety in Croydon Rental Properties
Asbestos old days rules continue to shape our housing stock but modern tenants have legal rights:
Landlord CO Alarm Obligations
In rental properties you must install CO alarms in every room with fuel burning appliances. I have helped many Croydon landlords bring older homes up to standard prior to new tenancy commencement.
Documentation for Safety Certificates
CO alarm checks must be recorded on Gas Safety Certificate each year. I include alarm test results in my annual service report.
Why You Should Trust a Local Croydon Engineer
Having lived in the borough since childhood I know its building types and quirks better than anyone.
Familiar with Local Construction Practices
I know which Croydon loft conversions were done without proper vents and which terrace chimneys share flues.
Rapid Same Day Call Outs
I’m usually 20 minutes from central Croydon. In case of urgent CO calls I can attend same day.
Parts to Fix Seals and Install Alarms
I carry flue seal kits CO alarm units and alarm test tools in my van so I don’t have to return later.
Link to Croydon Boiler Repair and Servicing
If you’re concerned about carbon monoxide risk or simply want a full boiler safety check visit our Croydon boiler repair and servicing page for expert local support.
Stay Safe and Carbon Monoxide Aware
Carbon monoxide is silent but deadly. As a Croydon boiler engineer I have saved families from gas leaks and made homes safe. Regular service visits, CO testing, proper ventilation and alarm installation are key to prevention. Don’t wait for symptoms or faults to appear seek a thorough inspection today, stay safe, secure and warm.