I know someone good in Kew, if that's any good.
I think these are the details:
Kew Boiler & Heating Services
94 Kew Road
Kew
TW9 2PZ
020 8995 2276
I'm pretty sure this is the same one we used - we got him off yell.com and he is called Eamonn (sp?). You could try ringing up and asking for Eamonn if you want to be absolutely sure.