As the nights start to draw in, the leaves start to turn and the temperature drops, people will be starting to put the heating on… And landlords are being advised that it’s a great time to get boilers serviced - and to check that carbon monoxide (CO) alarms are working in their properties.

The Government recommends ensuring that working carbon monoxide alarms are installed in all rooms with gas appliances.

Landlords should make sure the alarms are in working order at the start of each new tenancy, and ask the tenant to sign the inventory to record that the alarms have been tested. Monthly checks fall to the tenant, but should still be part of regular inspection or maintenance routines.

Landlords breaching the rules can be fined up to £5,000 where they fail to comply with a remedial notice, and local authorities are responsible for enforcing the requirements.

Carbon monoxide alarms with sealed batteries have a shelf life of around five to seven years - so it is worth checking your rental properties to see how old your alarms are and whether they need to be replaced. Alarms with replaceable batteries only last around three years.

Consumer charity Which? recommends paying around £20 for a reliable alarm from a reputable outlet, as cheaper models often fail their safety tests. You should also check for a Kitemark.

Gas appliances in your rental homes must also be serviced annually by a qualified Gas Safe Registered engineer.

Known as the silent killer, carbon monoxide is odourless, invisible and can be fatal if you are exposed to high levels.

Around 50 people a year die from CO poisoning and thousands more need hospital treatment.

It is created when fuel does not burn fully and household appliances, such as gas fires, boilers, central heating systems, water heaters, cookers and open fires - which use gas, oil, coal and wood - may be possible sources of CO gas.

Even if it doesn’t prove fatal CO poisoning can lead to lasting neurological damage.

According to the Royal Society for the Prevention of Accidents, those most at risk are the under 14s and the over 65s, with these age groups accounting for 31% and 25%of these hospital admissions.

Alex Huntley, Head of Operations at Simple Landlords Insurance, said: “After Grenfell, we know that fire and gas safety are top priorities for landlords, and this is a timely reminder about landlords’ responsibilities. Make sure your alarms are up to date and working, and that your tenants know what to look for.

“Warning signs that CO is present include things like boiler pilot light flames burning orange instead of blue, sooty stains on or near appliances, excessive condensation in the room, coal/wood fires that burn slowly or go out, and whole families suffering prolonged flu-like symptoms.”