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Batteries are in correctly. I was curious and double-checked that earlier this afternoon. I don't think the display will illuminate if they're in wrong, but no matter, they're in ok.
No bent pins. They all look straight, true, and show no other signs of trouble such as corrosion or being loose/wobbly on the circuit board.
FYI - I can hear the trigger mechanism click when the temperature reaches the desired set point, but nothing happens. (The furnace does not come on.)
I've tried to test the unit the same way in "Cool" mode following these steps: 1) Switch the Thermostat to the "Off" position and then wait a few seconds. 2) Switch it to "Cool". 3) Bump the current "Temp Setting" to current room temp and then a degree more (if the trigger has not already clicked). But in "Cool" mode, the thermostat will not trigger (click) no matter what the programmed temp setting is changed to, on, near. above, or below the room temp
I don't understand why in "Heat" mode, every time the temp setting is changed (bumped a degree at a time), as soon as it reaches the current room temp the unit triggers (clicks) immediately. In "Cool" mode it won't trigger that typical little click at all.
I have turned "off" and back "on" all circuit breakers connecting all components. Nothing seems to make any difference.
Thanks for your input thus far.
It's a gas (heating oil) furnace.
Let me jump those terminals now.
Ok. With the unit's body section removed from the wall plate/bracket, I see the wire hold-down screws. Slots read a follows from R to L:
"W" / "Y" / "G" / "B" / "O" / "RC" / "RH" / "C"
"RC" & "RW" are jumpered already, as are a few others.
I'll go ahead and jumper "W" to the "R" wires, but if I need to screw down the jumper and remount the thermostat body to the wall plate, I'll need a few short minutes more.
FYI - I did see a little tiny arc upon initial touching of the jumped contacts, so I know that there is power energizing one terminal to another.
Any other suggestions? I'll be around for awhile.
So as to be very specific,.....with the wiring harness exposed I jumped the "RC" + "RH" terminals (already jumped with a small black wire) to the "W" terminal. There was a small energy spark upon contact, but nothing came on.
I screwed the jumper in place and remounted the thermostat body to the wall plate. Bumped the temp override seting up and heard the unit trigger, but nothing came on. Still no air blowing yet.
I'm going to remove the jumper now, unless I hear otherwise from you.
ok. I've been in that blower/furnace unit a number of times, never having seen a diagnostic light of any sort. Just looked again now. I can't find diagnostic light. The unit is at least 13 years old.
It's an Addison furnace and a Ducane burner mounted inside it. If you want the model # XXXXX let me know.
When you say "Try to fire the furnace" do you mean do more than just have the thermostat settings in proper order for the furnace to come on? (That is to say making sure that the thermostat unit has triggered (clicked) "On" and everything else is already in place, prepared for a normal cycle to happen? When I stand next to the furnace under those normal "start-up" conditions, I hear and see nothing.
Or, do I need to go to the furnace and somehow initiate a start-up? That would be something I have no experience doing, nor see any manual way to do that. There are a lot of labels, warnings, and such (decals) inside the unit, but no instructions for re-lighting a pilot light or any kind of manual start-up.
FYI - I have been beside the unit many times in the past (it's located in the garage) and heard it initialize, and it sounds like a gas grill igniter kicking on the initial flame.
I already had the cover off where the back of the burner is exposed, and took the lower cover off to expose the squirrel cage. In the latter area, there are some wires draped from a terminal block to a switch type looking thing mounted in the interior of that area, but no fuse, auto type or otherwise.
Do you have a voltmeter to check for voltage on terminals. Russ
In the process of wiggling some of those wires around a little bit, the furnace ingited kicked on and the blower began to run too. It ran for about a minute, and quit. I just went through those same wires to check the connections, and cleaned up a couple of male-to-female push-on connectors that looked like they might have been a little corroded. I had the wall switch that controls the air handler "Off" for safety's sake. (Figured that if there were loose connections in there, I didn't want to cause intermitttant connectivity, so I switched the unit off.) Upon finishing, I flipped the switch "On" and nothing came on. Now I'm really at a loss!
FYI - The connections I refer to are integral to a small board of phenolic material that mounts over an opening into the burner chamber that has two insulated wires about 4inches long connected to a two-piece electrical component of some sort that's about dime-size in diameter and each half about 1/8" making it about the size of four dimes stacked up. One side black plastic, the other unfinished aluminum.
It's all back together and switched "On", but nothing's running.
Is the plot getting thicker? I am at a loss!
I might have a volt meter around. What range are we talking about?
Back of burner has a reset button and label (decal) stating to "Homeowner- Only reset once" and some other comment of sorts but I'm late for work running out the door. There are no wired there. Only a red button under a rubbery soft plastic piece of tape looking arrangement (like the soft "on-off" button on some flashlights, but thinner material).
I'll get back to you after 4:30 this afternoon with the rest of that decal's language and will neet to know voltage range we're talking about, too. I may have a meter, may have to go get one.