I am having problems with my wood burner making a humming/ buzing noise. It sounds like it is comming from behind the temperature gauge which has been reading a hotter temperature than what it really is. The needle is like buried in the gauge. The fans still kick on when they need to (under 150 deg). Also the air blowing though the exchanger is not as hot as it should be. there doesnt seem to be anyone close by that can service my burner so need some help thanks