Most engineers offer the annual check and the service as one visit because the travel, the access and the appliance are the same. That is a genuine saving and it is also where quotes stop being comparable, because a bundled price and a bare check look alike on a website and are not the same job.
What a boiler gas safety certificate and boiler service visit produces
Two documents: the record of the safety check that the landlord must keep and give to the tenant, and the service record the manufacturer's warranty relies on. If the invoice produces only one of them, ask which job was actually done.
Why the check alone is not enough for a warranty
Manufacturers require an annual service to their schedule. A safety check confirms the appliance is safe to use; it does not clean the heat exchanger or replace anything, so it does not meet a warranty condition.
A gas and electrical safety certificate together: the EICR and gas safety certificate pair
Landlords in England also need an electrical installation condition report every five years, and some firms offer it alongside. It is a different registration and usually a different engineer, so a combined booking is a scheduling convenience rather than one person doing both.
What the safety check does not cover
Radiators, the heating system's performance, water pressure over time and the condition of pipework beyond the appliance and its flue. The check is about safety, so a warm house is not evidence that the check would pass.
Questions people ask about gas safety check and boiler service
What does a gas safety check involve?
The engineer checks each gas appliance and flue: correct operating pressure, satisfactory combustion, the flue clearing the products of combustion, adequate ventilation and working safety devices, then records the result.
Does a gas safety check include radiators?
No. Radiators are part of the heating system rather than the gas appliance and its flue, so they are outside the statutory check.
Is a combined gas safety and boiler service cheaper?
Almost always, because it is one attendance. Ask for the price of each separately as well, so you can see what you are paying for.
Can I book a boiler service and gas safety certificate together?
Yes, and it is almost always cheaper because it is one attendance. The visit produces two documents: the safety record the landlord keeps and gives to the tenant, and the service record the manufacturer's warranty relies on.
When should I book a gas safety check?
Before the current record runs out, and for a let property in the two months before expiry so the new date still runs from the old one and the anniversary does not drift. Booking it with the service is normally cheaper than two visits.