Furnace Issue or Thermostat ?

bigdog · 12-17-2016, 07:44 AM

I have another furnace issue.... last week issue was at Mass house, bad gaskets around circulator pump causing leaks, that issue was corrected and all good now !

This week, came to NH home to check things, b/c of the sub-zero temps.
All seemed ok inside house, heat on and warm, Honeywell programmable digital thermostat was set at 55 degrees and holding.....

I bumped up the temp to 68, furnace kicked on and all seemed OK. Temp however continued to climb and couldn't seem to be controlled by thermostat.

I noticed low battery display flashing, so replaced with 2 AAA, and flashing display stopped ! The temp reverted back to climbing, I set thermostat down to 62, but display is now registering 71.

FYI, I did not replace with fresh batteries, b/c I didn't have at the time, could this still be the issue? Going to Wal-Mart today to get fresh alkaline batteries and replace to see if it makes a difference, TBD ? Could it be the thermostat itself or do you think the issue is at the furnace end ? Up until now, all have been fine !

Thoughts ?

12-17-2016, 07:44 AM	#1
bigdog Senior Member Join Date: Apr 2006 Location: Central MA-Gilford Posts: 1,452 Thanks: 347 Thanked 123 Times in 97 Posts	Furnace Issue or Thermostat ? I have another furnace issue.... last week issue was at Mass house, bad gaskets around circulator pump causing leaks, that issue was corrected and all good now ! This week, came to NH home to check things, b/c of the sub-zero temps. All seemed ok inside house, heat on and warm, Honeywell programmable digital thermostat was set at 55 degrees and holding..... I bumped up the temp to 68, furnace kicked on and all seemed OK. Temp however continued to climb and couldn't seem to be controlled by thermostat. I noticed low battery display flashing, so replaced with 2 AAA, and flashing display stopped ! The temp reverted back to climbing, I set thermostat down to 62, but display is now registering 71. FYI, I did not replace with fresh batteries, b/c I didn't have at the time, could this still be the issue? Going to Wal-Mart today to get fresh alkaline batteries and replace to see if it makes a difference, TBD ? Could it be the thermostat itself or do you think the issue is at the furnace end ? Up until now, all have been fine ! Thoughts ?