While most people understand what a boiler, tap and cold-water tank do (There's an explanation of different types of boiler here) some other parts of a plumbing and heating system may be less well-understood so we're building a list of useful terms. Please let us know if there is anything you think should be added?
Magnaclean Filter. A filtering device containing a very strong magnet and cleanable filter installed in your heating pipework which catches any passing pieces of rust coming from the interior of your radiators, protects your boiler and reduces the need for Power Flushing.
Power flushing - Removing the sludge from your heating system. See our page Power flushing!
Thermostatic Radiator Valves (TRV’s) enable you to control the individual temperature of each room in your home, and can be adjusted to the comfort levels you want. The higher the number selected on the TRV, the hotter the radiator and warmer the room. Please note a TRV should not be fitted on a radiator in the same room as a room thermostat.