Hello, I had an extension built for me by a small company; we were recommended them through a friend who had some work done by them. They completed work on the extension and it passed the 1st couple of stages of building regulation. There were a couple of really small jobs left to do but that was only notified to us just before lockdown & he hasn't returned to complete them yet. We can get those resolved very easily anyway. However, as part of the work on the extension we had our combi-boiler moved from one part of the kitchen into a new part of the kitchen. We haven't had a certificate to show that this work was carried out by a competent person. In fact, I suspect that this wasn't carried out by a competent person even though he said that it would be. My wife & I weren't at home when the work was being carried out so we are not sure. But given that he hasn't provided a certificate & now refuses to help us resolve this I believe he probably didn't. The last time we saw him we were trying to finalise how much we should pay as there were a few thousand to be paid on completion (& we were waiting for a certificate). Due to lockdown we haven't been in touch with him much & he's not responding. Because we weren't happy with some aspects of his work & made him redo some things, or reduced how much we would pay him because we had other people fix things (electrics) he seems to want to be done with us. So my question is, what do I do to get the boiler checked, safe, and certified? Summary: Small company did an extension for us, it is mostly up to standard, but he didn't supply a gas certificate, may not have done it legally, and will no longer interact with us.