Preface: we have had a Nest thermostat for a very long time. The old one was struggling to stay connected to the internet, so we purchased a new one Columbia Gas was offering, with a rebate. It was a much cheaper model.
From the start, we had problems with the system not working when the program called for heat.
The blower would come on and then go off, come on and then go off... this would repeat. Most of the time, after a few minutes, it would cycle up and make heat.
We called our local HVAC company and they came out and reviewed our entire system and said it's likely the thermostat. We changed the batteries, he cut the ends of the wires and stripped a new end on each wire (both ends) "just in case" ... etc.
Put the new batteries in and it worked great...for a couple months. Then it started doing it again, only this time it just wouldn't ever allow the cycle to go long enough to ignite.
We had the HVAC company out and they told us something was wrong with the furnace... due to it's age (it's 22 years old) it would be best to just replace it (of course they would tell us this...).
I was about to place an order for a new unit when I talked to a client who I learned works in the HVAC industry as a contractor. I told him what was going on and he said... has to be the thermostat (I forgot to mention... the HVAC guy was able to get our furnace to work by removing the R & W wires and then jumping the R & W screws with a jumper wire.)
My client suggested that we purchase a new (higher quality) thermostat before buying a whole new system. So I ventured out to HD and bought the best one they had and had it installed.
I reset the program and bingo... it fired right up and is working great...all is well with the world.
NOW TO THE ISSUE AT HAND:
While admitting the furnace appears to be working fine, there is one hiccup that has my wife freaked out that it's going to 'die again.'
When the thermostat calls for heat, because the temperature in the house falls below what I have the program set for, the blower starts up, and after a brief second or two, cuts out for a split second, and then re-engages again and then runs fine.
I describe it like this (if you remember the days of manual transmissions): I leave a stop light and go through first gear, I simultaneously let up on the gas and push the clutch in while shifting into 2nd gear. The brief second I let up on the gas, that is kind of how I'd describe what is going on with the blower ignition sequence. When the Program calls for heat, it does this.
Note: If we go in to our phone and the app and bump the temperature up manually (overriding the program), the furnace begins it's ignition sequence and does NOT experience the split second hiccup of the blower.
It almost has to be a glitch in the thermostat, right?
Note: Since installing the new Nest about 24 hours ago, the above scenario happens 100% of the time. Again, if the program calls for heat, it has the brief hiccup in the ignition process, but then runs flawlessly. If we override the program and call for heat, it doesn't do this. It just runs flawlessly.
Any thoughts would be very helpful. My wife has a chronic pain disorder that is significantly aggravated by cold and so the few days we were without heat and using electric heaters to get by really caused a flare up for her. Now she is panicking and just wants me to replace the furnace.
While I'm not a HVAC expert, it does seem logical to me that this is a NEST caused issue and getting a new system, and keeping the brand new NEST won't change anything.
Thoughts?
