John was a fantastic choice, very prompt with accepting the job and getting in contact with me as well. He made the first visit to diagnose exactly what the issue was and what was causing it, very conversational and cheery throughout. Once the diagnosis was done we got the part ordered and he was around a day later to fit it, tidied up some cable management in the process.
Heating is now working perfectly and, most importantly, silently!
Not only was he pleasant to talk to and very efficient with the work, but I also reckon his price would be very difficult to beat.
I'll definitely be recommending him to friends in and around the area should they need any heating related work.