Hello,
We had purchased a new Reznor heater for our garage a couple of years ago. We noticed that every once in a while when the burners would ignite, you would hear a big wooshing sound and flames would shoot out of the bottom of the heater. The company we purchased it from checked the gas pressure multiple times, changed the gas valve and even the heat exchanger after it finally cracked. By this time, the heater was out of warranty and they washed their hands of it so I was left with a new, unusable heater. I phoned Reznor and the gentleman I talked to said it sounded like a draft problem.

We then decided to upgrade to a high efficiency furnace in the house and I installed my Carrier furnace that was new in 1997 when we built the house and is not high efficiency in the garage. After one year, the flue is full of soot. I'm told that this is probably a symptom of bad draft also. The flue goes straight up to a drip tee and from there, straight up through the single story roof.

Should I add a draft inducer to the flue? Is it possible to convert the furnace with a draft inducer to draft out the side of the house or is there another possible cause of my problems?

Thank you for any help you can provide.

the flue is full of soot

Please call a REAL professional to check out this condition. Special tools and knowledge are needed to properly set up a burner no matter what the efficiency.

The problem with your garage heater was delayed ignition and that should have been fixed easily by a knowledgeable company.

A draft inducer should not be considered until a professional ON SITE survey is done to determine for sure if the unit truly needs one or just adjustments. NOTE: furnaces as shipped from the factory need to be adjusted after they are installed. That is why the instillation instructions have a start up and check out list that is used along with standard HVAC protocall.

I finally found someone that knew what he was doing. The problem was that my garage was too tight and I had no make-up air, causing the garage to acually create a negative pressure situation and a down draft in the flue.

Thank you for your help.

How stupid is studid could stupid could be. It amazes me how many idiots we have out there installing CO producing products. That goes for contractors and homeowners. If they bothered to read the install manuel please.