Carbon Monoxide Investigation

What a carbon monoxide investigation covers

This service is designed to identify whether carbon monoxide is being produced or entering living or working areas, and why. Your engineer will focus on safety first, then provide clear, actionable findings.

• Targeted checks of the appliance(s) linked to the concern (boiler, fire, cooker or other gas appliance)
• Inspection of flues, terminals and signs of spillage or poor draw
• Testing for combustion issues and potential carbon monoxide risk
• Assessment of ventilation and air supply to the appliance
• Checks for faults, incorrect set-up, blockages or deterioration
• Advice on immediate safety steps and the most effective repair options
• Written summary of findings and recommended remedial work where appropriate

When this service is most relevant

Book a carbon monoxide investigation if you have any concerns about fumes or combustion safety, especially if:

• A carbon monoxide alarm has sounded or you suspect it is triggering incorrectly
• Anyone has headaches, dizziness or nausea that improves when leaving the property
• You notice sooting, staining, yellow flames or unusual smells near an appliance
• There is excessive condensation, poor ventilation or a recently altered flue area
• Tenants have raised concerns and you need an independent, safety-led assessment

If you believe there is an immediate danger, stop using the appliance, ventilate the area and seek urgent assistance.

How the investigation is carried out

The visit starts with a short set of questions about the symptoms, alarms and which appliances are in use. The engineer then inspects the appliance and its flue route, checks ventilation, and carries out relevant tests using approved equipment.

If an appliance is found to be unsafe, it may need to be turned off and labelled to prevent use until repaired. You will be talked through the results in plain English, along with the safest next steps.

What happens after the investigation

You will receive a clear explanation of what was found and what action is required. If remedial work is needed, you can proceed with targeted repairs rather than guesswork.

Where appropriate, you can also request any relevant Gas Safe documentation linked to the work carried out or the safety status of the appliance.