DIY Doctor UK DIY Forums

I moved into a detached bungalow last June, and last Sept I had a gas fire fitted in the lounge. Soon after this I started hearing a loud popping/banging sound in the middle of the night, loud enough to wake me. I called the fitter who did come back. He checked the fire and said it was ok and the noise was nothing serious. However the noise continued, so I called him again, but it didn't make any noise when he was here. He asked me to record the noise when it started again so he could hear it. The noise then stopped altogether and I didn't hear a thing all Summer,but last week when the temperature dropped the noise started again. The cold seems to have triggered it and it starts in the middle of the night or the early hours when it's coldest. It stops when the temperature rises later in the morning. The nose is so loud it makes you jump and sleep is disturbed. It seems to come from the wall where the fire is fitted.My bedroom is next to this, and the noise is just as loud on the same wall in the bedroom. I will record the noise and call him back, but what can he do about it? Is there any advice as to what he could do? I can't think what else would make the noise. There is a water tank in the loft, which could be affecting the joists it's resting on, but the sound I'm hearing seems to come more from the wall itself by the fire. Has anyone come across this problem before? Thanks.