Lennox Pulse


Old 01-27-13, 09:06 AM
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Lennox Pulse

I have a Lennox Pulse G1-4Q3-80-CS that was installed in 1986. In the last two months, the air intake tube has started to build up frost to the point of plugging it up. As a result the furnace tries to start, but shuts itself off. I have to clean the intake daily to ensure it doesn't get plugged up. It seems as though there is warm air escaping from the intake. What might the problem be and is it worth repairing or should I consider replacing the furnace? It has been very efficient, costing under $600 per year in natural gas for a 2,300 square foot home.
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Old 01-27-13, 01:01 PM
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Just in the last two months ?
Sounds like something must have changed.

Was there a pvc fitting on it that may have fallen off ?
Maybe like the fitting on the left.....a 90 degree.
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Old 01-27-13, 03:05 PM
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Th 90degree fitting is still there. The only thing that has changed is that in October, I replaced my electronic air filter, which wasn't zapping anymore, with a disposable filter.
Old 01-27-13, 03:38 PM
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I don't know much about pulse units but know that they should be pressure tested every few years.

The heat exchanger could be leaking. (not related to the combustion air problem)
Old 01-27-13, 05:29 PM
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The heat exchanger needs to be pressure tested before spending ANY money on a repair for that furnace. Pulse parts are very hard to find today. They no longer make a furnace like it. I'm sure you would not mind a MUCH quieter furnace either.

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