Question about Honeywell Programmable Thermostat Heater
This is a long post, but I suggest you read the whole thing before doing anything.
1. Remove the face of the unit from the wall, then remove the plastic casing that covers the touch screen. It takes some force to remove it, and it will snap as you pull it off (sounds like it's breaking but it is not). Then remove the circuit board (with lcd attached) by moving the tabs on the left and right outwards at the same time (you can see where the tabs are securing the screen in the casing).
2. Near the top there are too small ribbon cables that plug into the circuit board. They are fragile, so be careful with them. On the board, you can see the connectors marked for touch screen and lcd. One for each cable. There are two small tabs on either side of the cable. Pull up slightly on the tabs at the same time and they will slide up only 1/8 of an inch or less (very small amount).
3. Carefully slide the cable out (upwards, if you were looking at the touch screen) and then slide it back in to ensure it is fully seated. Again, be careful with these cables, as they are fragile. If your touch screen does not work, then you should only have to reseat the touch screen cable. Reseat the lcd only if there is a problem with the visual display.
4. Insert the lcd screen back into the casing by pushing it straight in (there is a small hole in the lower left corner that matches with the casing). Reattach the plastic cover by snapping it back on (should go back on with some force if you line it up correctly). Finally, reattach the entire face of the unit to the wall (make sure you line this up as well, the pins have to be inserted correctly to avoid breaking them).
If everything works now, then you are back in business. If not, you probably broke your touch screen.
Posted on Dec 11, 2010
We have a thermostat that has 2 settings for the fan ( 1 ) is "ON" and ( 1 ) is auto which setting do we pout the fan on in the winter
Posted on Dec 16, 2008
The fix that TurtleDriver suggested fixed mine. I had to reseat the ribbon cable for the touch screen. The first couple of times it didn't fix it, but then I thought maybe the ribbon is worn where it is making contact, so I inserted it fully then pulled it back a touch to make it clamp on a new part of the ribbon and all is good now. First problem i have had with these and I have had two for several years. Thanks TD for the tip.
Posted on Dec 29, 2015
You are awesome.
Worked like a charm!
Posted on Jan 17, 2013
I had the same problem. I tried the same solution - removing and then putting back the wires. Works fine now. Makes one think about buying another Honeywell if they have such a well-known defect. I bet it's made in China.
Posted on Jun 23, 2012
Your screen is locked it happens with that particular tstat for some reason but you can try to take the batteries out and let it sit for a few but most likely you will have to get another one i am an hvac service technician and have seen it alot in fact it happen to m ine thats why i dont use it anymore sorry for the problem
Posted on Jan 19, 2012
Hold down the system button on the left side of the screen for a few seconds then after the screen changes hold the two buttons to the left and right of the center button on the bottom of the screen then use the left arrows to get to 670 and the right arrows to get to 0 that is how I unlock mine? Good luck!
Posted on Oct 20, 2008
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Posted on Jan 02, 2017
Whoa, that stinks..... I think that is the first problem I have seen with those t-stats... they are very dependable....
I would take out the batteries and let it die for about a day....I think it takes that long for the capacitors to fully discharge... Don't know what you will do for heat while your doing that, unless you know how to jumper the furnace... R-W on the circuit board will get you heat....
Then reinstall the batteries and the t-stat and see if it comes back....
Oh and make sure you also leave it off of the wall so it don't get power from the furnace either... you want it to completely die... then you will have to reprogram it... so I hope you still have the manual...
Posted on Nov 26, 2010
SOURCE: round honeywell thermostat
Sounds like you have a T86 thermostat...take the round front cover off to view the Mercury switch. Watch the bulb when you change the temperature to a higher setpoint. If the bulb makes contact when rotating it up, and the furnace doesn't go into a call for heat, then it could be the thermostat, wiring, or furnace problem.
Posted on Dec 15, 2013
Many thermostats have battery backup as well as the 24 volt ac. Have you replaced the batteries to see if it fixes all of your issues at once?
Posted on Nov 02, 2013
it not a touch screen, its manual old style honeywell, square box, not round, not rectanglur.
Posted on Nov 03, 2013
Testimonial: "It is a touchscreen. I have seen references to the battery being round and lithium CR2450; however, not sure if this is accurate. Does anyone know?"
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