THE Heating Helpline has warned that too many people still needlessly die every year from preventable gas-related carbon monoxide poisoning — a silent and lethal killer.

50 people each year are killed by its fumes and hundreds more made seriously ill.

Poisoning occurs when gas fired appliances such as boilers, cookers and fires are not operating correctly.

Homes with old appliances or appliances that have been infrequently serviced are most at risk, with research indicating that nearly a quarter of homes have one or more defective gas appliance.

Bob Towse, technical and safety consultant to the Heating Helpline, commented: “It is essential that gas appliances are maintained in good condition and subject to annual maintenance and safety checks by a qualified Gas Safe registered engineer.

“If your boiler is more than 10 years old or has been infrequently serviced in the past, you really should contact a registered engineer to have your heating system inspected.

Even though you cannot see or smell carbon monoxide there are vital signs to look out for such as: - Sooting and staining on or around your gas boiler or other gas appliance.

- Excessive condensation in the room where an appliance is installed and - A lazy, yellow-orange gas flame instead of blue.

Symptoms of CO poisoning include headaches, dizziness, tiredness and nausea and can be mistaken for flu, a virus and even food poisoning.