Urban Plumbers

I charge ?120-180 for this kind of work. Time depends on size and type of your central heating system. Full drain down may not be required as you may be able to turn all valves off on other radiators - provided they work and just drain the one you are replacing. Depending on type of the system I would allow between 2-3 hours for the job. It is a good practice to add inhibitors when system is partially drained. If fully drained (not likely to be needed) then inhibitors will have to be added.

It seems there are a lot of guys offering gas certificates for unrealistically low prices (?30-?40). As a gas safe registered business myself I would think that in London around ?50+Vat would be a minimum rate that makes sense for a self employed guys to do a thorough inspection provided it is done locally to the business. I try to keep my prices reasonable so if anyone is interested in gas services please get in touch. My web site is landlord gas safety inspections