Radiator Bleed Valves

Hi Mark, Good to hear you're having a go at it yourself. First of all may I recommend you undertake the task when the radiator is cold and the central heating is off to protect against burning yourself from hot water. 1) make sure BOTH radiator valves are fully closed. (The valves are located in the bottom corners of the radiator) This may well require you to remove the blanking cap from the return valve on one side before you can access the brass valve head. To close this valve you will need a key or a pair of pliers or an adjustable spanner, turn the valve clockwise until it turns no more. Apply the same to both radiator valves at both ensd of the radiator. The other end may be a manual winder(no need to removed the plastic handle) or a thermostatic valve, if it is the latter wind it closed clockwise to 0 or a little * frost symbol. Once you are absolutely happy you have shut off both valves. Place some towels under the rad and with a cloth in one hand CAREFULLY and slowly undo the valve. You will know straight away if there is water under force leaking go back and check above. With rag to hand you can mop up any residual as the black water doesn't blend well with white wool carpets ;) Replace the faulty valve ensure it is fully shut, proceed the reverse of above to open both valves then proceed to bleed the radiator with caution. Fire up the heating, monitor by touching the radiator from the bottom up that the heat rises to the top of the radiator over time, sit back and enjoy a job well done.

Turn off central heating system. Combi boilers are sealed systems therefore will be under pressure 1bar and above. You could drain the pressure to zero then turn off lock shields at both ends of the radiator then go and do what you intend to do to replace bleeder valves. Before doing so make sure to have waterproof covering to protect flooring. The other things to consider is the radiator valves may not be completely locked off properly due to age and hard water thus preventing leaks onto flooring. There is also gravity fed central heating systems which has a header tank which is normally located in the loft. There should be a gate valve or isolation valve if none of them turn off mains water supply to the tank lock both lock shields off at either end of the radiator then change the air bleeder valve as described above. If you decide to replace all them you may as well drain the whole system to replace TRV,s or Lock shields if you do, dont forget to put heating inhibitor back into your central heating system. 1. It stops rust inside out on central heating systems and radiators it can void boiler warrantee if not put back into the central systems. 2.Prevent heating system creating hydrogen which in-turn dumps water through Pressure Release Valve (PRV) and creates loss of pressure on central heating system then boiler wont work as no pressure which can happen. If you are happy with the information provided please tick thank you.