My furnace is cycling too often..

[charlezcold]

Hi everyone... this forum is great!
My wife and I just bought an 18 year old house, with dual ac/heat units for upstairs downstairs. The downstairs unit works perfectly. The upstairs unit is a different matter. You can hear the gas start to heat up; then the fan comes on, and it blows warm air - for about 20 seconds. Then it shuts off. In about a minute or so, it repeats this process. About every third cycle, it makes this popping sound, sort of like when you turn off your gas grill, (a mild "whoof").
I have replaced the old standard thermostats upstairs and down. Again, this is perfect downstairs. But upstairs, it has had no positive effects. Any ideas?

[16x80]

charlezcold

Welcome to the Home Repair Forums


Your problem is very likely due to bad air flow. Weather it be undersized duct work or a dirty or clogged coil/filter, also you could have a bad control/limit. More information would be helpful.

16x80

[Denmark116]

I would also check to see if your motor or "squirrel cage" is dirty or plugged.... If so, take a wet/dry vac and set it to blow (not suck) and blow out the unit. If there is still alot of garbage in there, pull out the "squirrel cage" (I.E. the fan) and give it a good cleaning.... (scrape the crap off of the blades with a screwdriver and suck them out with the wet/dry vac)...

Additionally, chek your filters and make sure to change them every month or so during heating season (especially if you have dogs or cats).

Hope this helps...