Had some hot air heaters checked for winter. Tech used a meter with a probe that goes into the chimney tube and reads the level of CO. Two were fine and one was bad. It's one I want to replace anyway since it's 12 years old and it's twin caught fire last year inside. It was caught in time and shut down and replaced.

What does this CO reading tell them? i suspect the burners are dirty and need to be cleaned as they probably have an orange flame. Or is it due to some valve inside releasing the wrong amount of gas to burn or oxygen? What would you do in this case?

A probe that detects CO can help the technician know if the exhaust gas is being properly removed from the furnace or boiler. It can also give an indication of whether or not the flame is burning at the proper rate & efficiency. High CO readings can indicate incomplete combustion, a blocked flue or an exhaust fan that is not running properly.

Allym from what you describe and have knowledge of is CO2 inside is within levels.

My gas furnaces have -- on the flame rails --- adjusters to mix air and gas. The gas is sent into the gas bar and draws air into the rail to mix with the gas. On the air inlet side of the bar you should see adjusters that allow more or less air to mix. The adjuster is opened or closed as you watch the flame on the bar. Should be BLUE flame with nice tips. The flame should be just staying on the bar.

Well thank you myob but I can't do any of that. My eyesight is not that good. So here's what happened today. Got the heater company out to give me an estimate on a new heater.

First thing the guy looks at the flue and wonders if it's any good and it has stainless steel liner. Then he says it might not be large enough. Well I have a permit sticker on there that says it is because it's been inspected.

It's 40,000 BTU and 80 percent. So he sells Carrier and they don't have that size. They have it only in an larger size. He offers me Payne or Goodman! I say no thank you and while he is writing up some paper work I go call two more companies. One has only Goodman and Coleman in that size so I say No Thank you. I learned here that Goodman is not that good and I didn't know the camp stove people made heaters. Nobody would have parts for that.

The other company, very good and in Princeton so not as close as I would like but they have a Trane in the size I need. The one I am replacing is a Trane. So their salesman will come on Thursday and I have to be at three other properties but they are only blocks apart so I can do it.

So the "green" people are getting ahead of us with furnaces. Carrier has caved into them by not having the smaller furnace and 80 percent. I don't like Carrier anyway as their oil fired furnace had a plastic Impeller in there and when it got colder and the oil got thicker it would not flow. I replaced that piece of junk. That had me out in frigid nights three times over a Thanksgiving.

I didn't know it was an oil type. When we lived in NY that's what we had. Huge tank (500 gal). my job was to pack the grease into the bearing port. Other than that not much to do.

We now have 63 Goodman HVAC systems. They are easy to work on and since there all the same== we can stock standard parts-- ignitor, flame sensor, exhaust gas fan assy.

I'm curious about the Flu? I have an 80% and use 4 inch flu's?

How big a pipe he want? He's upselling and price gouging.

Yes, I have two, four to five inch flues with stainless steel liner. They are gas hot air heaters, one for each floor and the floor space is about 650-700 square feet depending on upstairs or down.

The owner called me tonight and is going to send me an estimate for an 80 40K BTU Trane unit. The dumb guy yesterday who tried to upsell me did not even know they actually could sell me a Trane. He tried to call the owner and could not get him on the phone. So I said good bye to him. His shop is closer and he says he has a plumber working for him. But I am having trouble getting past the dumb guy who tried to upsell me. He is the installation foreman too.