The domestic central heating boilers have controlling devices so that their operation can be monitored, but should one or more fail or malfunction it will cause serious problems for the homeowner. There are very basic visual inspections that you can perform yourself, such as a check on your programmer/ time switches, thermostat, and radiator valves. The owner really should not attempt any DIY fault finding on their own as this is better in the hands of a professional service. Professionals like Clerkenwell Plumbers can keep your boilers and heating system serviced and fully operational. When a system ages, the thermostat for the boiler may lose its accuracy and be intermittent in its operation. A gas boiler engineer like a Clerkenwell Plumber will visually inspect your old thermostat, it may even be a good idea to let him install a new one. Thermostat:There are programmable thermostats that control the heat production in your house, turning the boiler on when you need it and reducing the heat when you don’t need it. Thermostats can cut heating bills by 10-20%. The hot water and heating is controlled by the timed /off/ constant switches fitted to your boiler. Visually check the LCD display and check that it is accurate. Heat:Something called a lock-shield valve fitted on a radiator is adjusted by removing its plastic dome shaped cover. Adjusting this valve will increase or decrease the water flowing through the radiator. If nothing happens after any adjustments to the valve settings, it may be a fault with the radiator valve so call a Gas Safe registered professional. They will drain the system, replace and refit a replacement valve. Pipework:Pipework is fitted that will take any condensation from the boiler to the outside. When the weather is really cold, this condensation will freeze resulting in a blockage and this will stop the boiler from working. There is a warning of this condensate freezing on the boiler’s display in the form of a ‘fault code’ or a warning light. You could even hear a gurgling or bubbling sound from the boiler or the even the pipework itself.