I have a Lennox Whisperheat G20 furnace that was installed around 1992.
These units where available with either ignition or a standing pilot.
Mine has the standing pilot.
Not too many years after it was installed it needed a new heat exchanger.
At the time I had several people look at the installation and nobody could
see any reason it would have rusted.
I've now found several old posts from this forum (around the year 2000) on
google indicating that there was a problem with the standing pilot models
because the damper door was cutting off air to the pilot when the furnace
was off, causing them to rust.
Looking at the unit now (though I obviously can't see the heat exchanger)
things are looking awfully rusty, and I'm not going to use it until I can
get it looked at.
Does anyone recall this or have any information on this defect? I called
one Lennox dealer in my area today and they sort of pleaded ignorant about
it. I plan on calling others.
Thanks a million in advance for any information.