Well, it's in the 50's here in Dillon Montana...brrrr. I haven't run my furnace at all, I have my Granger's heater keeping the living room toasty, and a small automatic electric heater in the bedroom cycling on and off.
Those of you at the 'Stick house' mostly have gas heat... I know there are others, electric, heat pumps and other types, wood, so on.
My post is to help understand the most common reasons for a 'no heat' service call. Motors failing, you will easily know when this happens; you have the blower motor, if the heat comes on, no fan after a while, easy diagnose. Just switch on the thermostat 'on' switch, no blow: bad motor. (Around $200.00 plus labor)
Combustion blower motor: when a call for heat, this noisy fan starts up and runs, if you don't hear it come on, it's probably bad.
(around $200 plus labor)
1/2 that if you do it.
The most common problem is a dirty flame rod, (picture below) extremely rare that it needs nothing more than a cleaning with a scotch-bright (Green dish scrubber) Most service guys replace the rod with a $60.00 new one. You can clean it in place.
In a dirty environment, the pressure switches fail. $60 or so.
Another common part that fails is the Igniter, $60-80
Slide show below on Igniter replacment, then movies showing repair.
https://picasaweb.google.com/Jimsue1...eat=directlink
First movie showing defective Igniter
https://picasaweb.google.com/lh/phot...eat=directlink
Second movie showing defective part, removed:
https://picasaweb.google.com/lh/phot...eat=directlink
Third movie showing new part working:
https://picasaweb.google.com/lh/phot...eat=directlink
Flame rod:
Hope this may help you out.