I have a natural gas boiler that was manufactured about 12 years ago, but never installed or used until November 2009. Our gas plumber told us he bought 8 Lochinvar boilers in bulk many years ago and has slowly been using them over the years. I know the usual sounds like gas igniting, pipes knocking and small ticking sounds of water heating, but this is one loud bang upon start up. We also feel we are getting some sort of emission in the basement even though the carbon monoxide meter reads zero and the gas man's sniffer picks up nothing. Every time a guest goes down into the basement, they tell me there is a gas smell. It doesn't smell like unburned gas to me, but there is something there. We are selling this house and it is vacant. I just want the contractor who installed this to switch it all over to oil at no cost to me because it is scaring off my buyers.
Personally I don't like Lochinvar boilers. They have a copper tube heat exchanger which is susceptible to surging and possibly an occasional bang. If the installer installed a bypass between the supply and return pipe this would alleviate the problem. As far as the ticking sound is concerned that will probably remain as this is caused by the fins on the exchanger moving during expansion. Also it is not unusual to get an odor which could be mistaken for gas coming of a new device after it is fired for a few days or maybe a week, this is a coating on the exchanger that is burning off and will not last. Also make sure the operating limit is set no higher than 170 on that Lochinvar. Don't be afraid of calling a second contractor if there is anything wrong it will be found. Also you could try Lochinvar if the problem is that bad they will send you towards a local rep to check it out.
have you asked the contractor to sort it out. Expecting some one to do something like a conversion to oil is a bit unresonable just because you are selling the property. Get him back to fix it. If he won't their must be some kind of licencing authority policing the gas work and I don't think he would like them sniffing around.
