My gas furnace won't turn on, but I think it might be a Thermostat issue. Facts: Gas furnance with an electric ignition/pilot and a Honeywell 3200 thermostat. Before I call a maintenance man to check the furnace, I am considering just installing a new Thermostat myself. Thermostats are cheap, right? Maybe just change it and wait to call a repair man after that???? History, Three weeks ago the same thing happened. Furnace didn't turn on. It has an electric ignition (no pilot light), so I followed the instruction to reset it. Didn't work. So then I reset the thermostat schedule and I did something to make it work again. Yesterday it happened again, and this time nothing I do works. I downloaded the Honeywell manual and still found nothing I could do to get the heat on. Here's the Thermostat manual http://www.manualowl.com/m/Honeywell/CT3200/Manual/133935 The Thermostat FAQ section says this -- note this is not instructions regarding the furnace, but just the thermostat If the Heating won't come on: Check that the System switch is set to HEAT. (It is) Check the system fuse or circuit breaker and replace or reset if necessary (It works) Check for correct wiring and good connections (connections to thermostat seems fine) If display is blank or display "bAt Lo" install fresh batteries (it is fine, but maybe I should change batteries anyhow.) [*]If the temperature setting is higher than the current room temperature and the SYSTEM ON arrow is displayed. the thermostat is operating correctly.Contact a heating contractor for assistance. The last one is what makes me think I should call the contractor, per their advice. However, since the same thing happened 3 weeks ago and resetting the Thermostat seemed to fix it, I think it might be a thermostat problem, despite #5 above saying otherwise. tia
Thermostats are both relatively inexpensive AND relatively easy to install/replace. Staying within brand is easiest but even changing brands is pretty easy since wiring instructions will help you connect the correct wires. A heating contractor, on the other hand... can be expensive.
it's not possible to diagnose accurately with just that info. if you want to narrow this down yourself, all you have to do is jumper the red and white tstat wires either at the tstat or the furnace. if the furnace starts then you have a tstat issue. if not, something is wrong in the furnace.
rep for the advice. I'll have to try that next time. Coincidentally, yesterday after posting this, our furnace went out in the office, so a commercial contractor came out. I asked him if he does residential too, so I just hired him instead of trying to change the tstat myself. I think he did exactly what you described, among other diagnostics. It was the furnace, some carbon gunk had built up. And he also said the mixture was way off (almost dangerous -- too rich). So glad I called him. Dude only charged me $40. He was awesome.
