"I have had heating and air companies tell me in the past that I have a crack in my heat exchanger. I cannot see the cracks but assumed that you need magnification to see them. Is there a way to tell if this is true or if they are just trying to scam?"

There are a couple of things that should have been done there. If it is a very small hairline crack, you are probably not going to see it unless you have a heat exchanger camera and you go in there with a light and find it.

Different heat exchangers from different makers are more prone to fail in certain spots than others so it is important that you have that information also. A picture can be taken with these cameras or like with our devices they have a screen that the home owner can watch while the technician performs the test. This can and should be done so that you can be confident in the work that is being done and so that you can see what is they are finding.If they do find a crack in the heat exchanger, it should be disabled immediately because of the carbon monoxide risk. We disable all of ours when we come across this because it is a safety hazard. We do this because the risk of CO coming into your house is not worth the risk of not turning it off. We turn it off, turn off the gas, put a sticker on it, that way if a company comes behind us they will know that we a have found a cracked heat exchanger.

Now I have had these phone calls before where companies will come behind us and say they can’t find any leak. So I, on this occasion, asked the technician and he said to me, “did they take the top off the unit?” and they guy said no and so our tech told him that if he took the top off he would find the area that has the crack and it has a marker around it.

So if you are going to get a second opinion make sure you have someone that is qualified and knows what they are doing. This is nothing to play with. So you want to make absolutely sure that there is no crack or any damage before you turn that gas back on.

Your friend in comfort and energy savings,

Derek Cole