I would highly recommend Nathan from Therma-Dynamics.
He phoned a day ahead to confirm when he would be arriving to carry out the work on my heating system.
He arrived as planned and did a very thorough and professional job. He took his time and made sure that the repair was successful before leaving.
He explained what he was doing in terms that I could understand (well, just about) and was clearly very knowledgeable. Even though he was working in the bitter cold, he remained cheerful, friendly and smiley!!
Thank you, Nathan!! I will definitely be coming back again!!