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Handymannabee 04-12-2011 04:28 PM

Smoke and Vent on a New Lennox Furnace
I have a newly installed Lennox (EL195) furnace at home. A local contractor did the installation. The day the installation was done smoke filled our house and I was told it was normal. Smoke detectors sounded off that day. I was also told that it will not happen again. Days after the installation when heating would kick in we still see a bit of smoke in the house but the smoke detectors wouldn't detect it anymore. Is this normal? Is it safe?

I've read the installation manual. I could deduce that the our vent was installed on a NON-DIRECT way. That is, the exhaust outlet goes up and through our roof and the combustion air intake is terminated in our attic (not through the roof). They used PVC pipes for both exhaust and intake. I asked the installing techs about the possibility of rain water coming in through the exhaust, their answer was two 90 degree joints put together and placed at the top of the exhaust (it then look like a candy cane on my roof). The installation manual says that the furnace exhaust must me terminated straight up. Is my "candy cane exhaust" safe?

I wasn't clear on why they did not use my existing metal exhaust chimney which is now solely used by my gas water heater.

I'm days after the installation so I'm pretty sure I could still request for changes at will.

Please advise on how to make my new furnace safer. Thank you.

yuri 04-12-2011 04:51 PM

Some of them smoke a LOT when first started and may take a few cycles B4 it completely disappears. The metal in the heat exchanger is coated with oil when being drawn thru the dies and fabricating machine that makes it and has to burn off. Nothing to worry about. Your venting is safe and if pointed vertical the rain runs down the pipe and drains thru the furnace normally thru its own drain system. Nothing dangerous with what they did and may be better for keeping birds from nesting in a vertical pipe. You cannot attach those furnaces to a existing chimney as the water vapor in the exhaust will rot them out. Depending on how may feet of pipe and the # of 90 deg elbows they used the extra 2 elbows can cause nuisance pressure switch tripping problems in the winter. Let me know the furnace model # and diameter of pipe (2 or 2.5 or 3 inch) and measure how many feet of pipe and count the elbows and I can look it up for you.

Handymannabee 04-12-2011 11:34 PM

Yuri, first of all thank you so much for responding. I gathered the following for your reference:
1. My new furnace: Lennox EL195 UH070P36B-01
2. Length of exhaust vent (approximately): 13 feet
3. Diameter: 2.5 inches
4. Number of elbow joints used: 2 135-degree joints and the 2 90-degree joints at the top end of the vent
5. There is a 21-inch segment angled at 45degree in the middle of the vent just below the ceiling; sloping down toward the furnace

Hope this info helps. Thanks again.

yuri 04-13-2011 03:46 PM

You should be OK. :thumbsup: There is no 135 deg joint so I assume you are talking about a 45 deg elbow. 2 of them = 5 ft of pipe and the 2 90s =10 feet of pipe plus your 15 feet of pipe = 30 total. You can go 56 feet with 2" pipe or 105' with 2.5 inch pipe if you are under 4500 ft in altitude. Check the install manual p 17-19 for more info.:)

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