It is a legal requirement of the LANDLORD to provide a gas safety check as a must and all gas appliances should be serviced to helps keep your appliances running better for longer.
Each of YOUR properties that has gas in the property must have a gas safety check within every 12 month period by a qualified GAS SAFE engineer.
So if you're a landlord and you can not produce a up-to-date gas safety certificate then you are in breach of your tenancy agreement and more than likely invalidating your house insurance and that of your tenant.
Gas safety check provides;
a service is always a plus!