Does the blower run if thermostat fan switch is put in "on" position?
Don't have a fan switch on my thermostat
This unit did have a glitch in the circuit board that failed to turn on the blower. Unfortunately to find out means using a meter to see if the motor is getting 115v or not.
115v with no blower = bad motor
115v missing with no blower = bad circuit board.
So I can check for voltage at the terminals on the board, I'll have to check the manual's wiring diagram to see which terminals. If voltage is there, could it also be a bad capacitor (if they use a capacitor)?
A capacitor is either good or bad...yes it is possible it is capacitor..it would be attached to the blower housing with 2 wires from motor going to it. If this is a variable speed it will not have a capacitor. If you have Red, black, white, yellow or blue wires from motor it is not variable and will have a capcitor.
Basic Bryant, Carrier, Payne terminal would be labeled as Heat.
It's not a variable speed, I will check it tonight when I get home. Thanks for now.
I will leave this open for you.
Only 40 volts (???) on heat terminals (blue & Red wires). I forgot to tell you I replaced the hi limit switch initially & the furnace gives me a code 33 at first, then it changes to 13 after about 5 minutes. Are the relays replacable or is the glitch in the board itself, it couldn't be anything else right? The board is about $200 here in Canada. I'd hate to replace it for nothing. There's also mention of the fusible link possibly being bad, what are your thoughts on that? (that's that small firecracker looking thing on one of the red wires for the limit switch right? It just puzzles me that I can hear & feel the relays click when I run the component check & the relays click on the heat sequence & then the cool sequence, but no blower action. Can I use any other means of testing the motor. I tested the terminals with & without the motor wires connected & got similar voltages. Sorry to go on & on about this, but I'm just trying to wrap my head around it...
Yurn power off...remove wire from heat terminal and wire from L1 (black from door switch)use a small nail or paperclip and insert into each wire end thus joining them. Tape so no metal visible. Turn unit back on and tell me if blower runs.
You see I changed over 300 of these circuit boards on a huge failure with blower operation ...then I had to relocate those same 300 boards to the blower compartments so they ran cooler.
So I am used to failure with that board. But the test I explained will tell us.
Ah now that makes sense! I have two of these puppies in the same room, one for the upstairs & one for the downstairs, with the problem being with the basement furnace. I don't like the setup, because the basement is under-concrete ducting, yet the furnace is an up-flow with a goose-neck duct running down, so it would obviously run hotter internally than its upstairs neighbor (99000 Btu). So how would a guy relocate the controller to a cooler enviroment? I will go down right away to try what you suggested, I think we're getting there!
Yep! the blower works just fine! You obviously know your stuff! So whats my next move?
Thanks for the confirmation!
You need to replace the circuit board. The new board will not be encased in a black housing. This allows more air across the board.
Just pulled the board out & took the black cover off & one of the soldered terminals of the blower relay is black, like the solder let go. I should be able to clean & resolder it right? I used to operate a radiator repair shop, so fairly handy with solder. I'm not familiar with the clear sticky coating on the board, I assume it's to help prevent corrosion. Any thoughts on this? I was gonna order a new board on Ebay for $125, since our dealers here want $500! I guess it's worth a try & if it doesn't work, I'll order one.
It is possible to touch up the solder joint. I did it sparingly in a pinch and do not recommend a average homeowner do this....but it sounds thus far that you are capable.
You will have to carefully reseat the solder point on the back of the resistor (usually j7)
And then hope the only thing wrong is the solder joint that overheated. The coating is irrelevent.
Well it's working again, don't know for how long, the area was quite contaminated, I did mange to clen one side of the potruding spade & the schematic strip & was able to fold the spade over so I could get a "sandwich" joint, I'm crossing my fingers! Hey thanks for your help! No offence, but I hope I don't have to revisit this with you next week! Take care Billy!
Good job....at least you got it under control!
I pressed the accept answer button a little while ago, do you have a way of telling if it went through?