Question about Honeywell Programmable Thermostat Heater
I had the same problem with my Honeywell T80001C, after a vicious thunderstorm and a one hour power outage, during the monsoons in Arizona. No display on the unit when the power came back on. I new the problem wasn't a circuit breaker or GFI as the fan still worked when moving the FAN switch from AUTO to ON.
The three booklets that came with the unit were of no use in solving this problem.
I removed the unit from its wall bracket and toggled the switch on the back from "F" to "E" several times and back to "F" as suggested by others. The switch position depends on whether you have electric or gas heating. "E" for electric, "F" for gas. Put the unit back on the wall…. nothing. I tried this several more times and thought that this switch toggling was all bunk, then I read the solution by "collinator" and thought, OK nothing to loose, took it off again toggled the switch left it in the "E" position for 10-15 minutes, toggled it again, leaving it in the "F" position. After another half hour put it back and it worked!!
Can't believe it, can't explain it, as the other guy said - be patient.
Posted on Jul 24, 2010
Hi, I had the same problem with the 8011 and lost the display after a power outage. I took it off the wall and toggled the switch on the back about 6 or 7 times, replaced it back on the wall and it worked like a champ..thanks for the info!! Heres a good site to download the owners manual for a few of Honeywell T-Stats: http://customer.honeywell.com/honeywell/ProductInfo.aspx/T8000C1002 Just go to the bottom of the screen and you'll see the download button...Helps for resetting the T-stat..
Posted on Oct 16, 2008
Just a quick clarification for those who may have this issue in the future with their Honeywell T800 Thermostat. The display was blank following a lengthy power outage....
Checked all breakers, fuses and GFI plugs in the house to no avail.
Pulled the Thermo from the wall....toggled the switch on the back from "F" to "E" several times, making sure it was back at the "F" setting....replaced it and the display came on, but was not responding to inputs from the controls.
I pulled the unit again...toggled "F" to "E" and let it sit for 30 minutes or so....put it back on and it is now working fine!! It seems patience is key with these....
Posted on Aug 02, 2009
I too returned home after a 90+ degree day, power had gone out (sometime), no AC in house and no display on the thermostat. I removed the unit as others had suggested, and flipped the E/F switch. Sorry, didn't work for me. What are the E/F settings anyway? Mine was in the F position originally. BWT, I checked/reset all the breakers, etc. Now what???
Posted on Jun 27, 2008
I have a honeywell model number RTH221B.. i noticed today i have nothing on my display , i changed batteries , nothing happened , check circit brakers , looked ok... i even tryed shutting breaker n turining it bck on , still nothing.. fan comes on , but air And heat doesnt .. can anyone help ? thanks
Posted on Aug 03, 2009
I have a T8001C that was showing all LCD segments and signs lit up when I looked at it. My guess is that it happened after repeated power outages I had a couple of days ago. It has no battery. When I saw all the people talking about flipping the F/E switch and then it started working, I decided to pull the unit off the wall...it remained lit up. I just left it sitting there until I saw all of the LCD segments gone - blank screen (actually I waited probably 30 mins while watching a tv show... lol). Then I just popped it back on the wall plate. This fixed the display and the unit was working again. Hope this helps somebody. =)
Posted on Oct 28, 2011
Tried the "toggle and wait" technique...didn't work. In the troubleshooting section of the manual, suggests to see if the on/off switch by the furnace is "on." I have my golf clubs there and must have turned the switch to off putting them away.
Posted on May 10, 2011
This worked for me too... toggled the switch a few times then waited 15 minutes...
Posted on Dec 04, 2010
I had the exact same problem with the T8001C after a power outage. So I carefully took the unit off of its base-plate mounted on the wall. The unit was held by four locking tabs: two each on the top and bottom. After I pulled the unit off, I toggle the switch in the back a couple of times and put it back in its original position. I, then, put the unit back in its base-plate while making sure that the connectors mated properly. When I put the unit back in, the display came back on and the unit started to work again.
For now, I saved $169 on flat service from one AC repair company.
Give it a try, it worked for me.
Posted on Jun 06, 2008
My display on Honeywell T8001C Thermostat came back on and working again after I pull the unit off from its base-plate carefully, toggle the switch in the back of the unit a couple of times and back to its original position and put the unit back in its place making sure that the mating connector lined up properly.
Either toggling the switch did it or re-seating the unit did the trick.
For the time being I saved $168 flat rate service call from one repair company.
Posted on Jun 06, 2008
I woke up one morning and my thermostat was blank,the thermostat is a honeywell T8011R and does not require batteries.My system will not turn on,I need some suggestions on what to do to fix this problem.
Posted on Oct 18, 2008
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Posted on Jan 02, 2017
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