All gas appliances should be serviced at least once a year. This is to ensure the safe and smooth running of your gas boiler or water heater for the next twelve months. It is vital that all the safety controls are tested to ensure they are functioning correctly, and the flue examined to ensure you are not at risk from potential dangerous gas appliances. The internal components, such as burners and pilots should be cleaned to ensure they are burning cleanly and correctly, along with checking gas pressures and water flow rates. With condensing boilers, there are checks that should be carried out annually as per manufacturers recommendations, such as cleaning out the condense sump and flue analysis checks.