M Q wrote:
wrote:
Speedy Jim wrote:
...
Yep, they spec that so that condensation is unlikely
to occur in the main (pri) heat exchanger, which could
cause early failure.
It can become a warranty issue (if you care).
Jim
it becoming a warranty issue - how can they _prove_ I ever allowed
the temp to drop below 55F?
Of course, unless you bought the extended warranty, the heat exchanger
is likely to corrode through after your warranty expires.
I would also think that any concer over the return air temp being below
55 is likely predicated on it being under that temp for very long
periods do to some unusual furnace application not seen in residential
environments. It seems difficult to believe occassional operation
like that for say a vacation home, where it will only run below 55 for
short periods, followed by heating fully to normal temps, is going to
cause problems.