Old Furnace Keeps Tripping Circuit Breaker Can't Turn On Power
#41
07-09-15, 08:24 AM
I think this used motor I bought last year died on me. I was trying turn on just the fan from the furnace but nothing happened. I put it on auto and nothing happen. I had the heat come on ... the furnace kicked in, but the blower didn't .... could the motor be shot?
Last edited by spirittoo; 07-09-15 at 08:52 AM.
#43
07-09-15, 07:38 PM
Please tell me how to check it.
Okay ... can you tell me how to check it. Where do I put the multimeter probes on the motor? I have it on AC correct? Is there something that has to be disassemble in order to test for power? I just turn on the furnace by turning up the heat and check for power when I hear the furnace kick on? Or can I just put the fan on manual with out turning on the furnace and check for power? Thank you for reading my post.
#44
07-09-15, 09:11 PM
Group Moderator
You can take the plate back off the motor to check for power there or follow the metal clad cable to where it connects at the control box and check it there.
You can put the thermostat in FAN ON mode to check for power as long as putting the stat in FAN ON turned on the blower in the past.
You can put the thermostat in FAN ON mode to check for power as long as putting the stat in FAN ON turned on the blower in the past.
#45
07-10-15, 08:01 AM
I never used the FAN ON before so I don't know if it would work or not. Am I looking for a voltage reading ... if so what? .... amps? what is the correct output I should get? Thanks for reading my post.
#46
07-10-15, 07:38 PM
Group Moderator
#47
07-16-15, 08:24 AM
No Power To The Motor
Well sir .... I checked for voltage and I am not getting any reading when I pulled the back plate and put the probes to the screws where the wires are hooked up. I didn't know what the polarity was so I tried both ways. No power either way. I had the furnace switch on and fan switched to manual ... nothing. So does this mean there is something wrong with the switch since the motor isn't getting any power???
#48
07-16-15, 07:30 PM
Group Moderator
Back in post 9 you posted a picture of the fan/limit switch. On it is a manual on fan position.
Did you try that ? If that doesn't work you will need to trace the 120v wiring from there back to the junction box where the main power enters the furnace.
Did you try that ? If that doesn't work you will need to trace the 120v wiring from there back to the junction box where the main power enters the furnace.
#49
07-16-15, 09:11 PM
Hummm ... not sure I follow what you are saying.
Okay ... I'm trying to understand what you said. Trace the wiring back to the junction box? If that is to find out whether or not the furnace is getting power I know it is, because I can here it click on when I turn up the thermostat. It's just that the blower doesn't come on as it should. So since the blower motor isn't getting any power can it be the fan switch in post #9?
And if so how could I find a replacement with out a current part number?
And if so how could I find a replacement with out a current part number?
#50
07-21-15, 10:27 PM
Test? Replacement??
Can't anyone tell me how to test that switch? If the motor isn't getting any power and the furnace is ... wouldn't that be an indication the switch is bad? Does anyone know where I can get a replacement???
#51
07-26-15, 12:35 PM
Still need help finding replacement switch ...
I believe the switch is bad since no power is reaching the motor ... can someone tell me where to look to replace it???
#52
07-28-15, 10:18 AM
Found it ...
Well sir ... since I didn't get any response here I found another forum where the posters were able to help me. The fan is Honeywell Combination Fan And Limit Control L4064 B 2210. I was given a link to ebay where they were selling them. I had to find one that was the same length as mine which is 11.5". With the part number it was easy to find. I was able to get one for $42 to the door. I saw the prices varied between $35 - $90 some where the same product with a higher cost.
I also got some other good links that will be helpful for folks with my similar situation ...
How the Honeywell fan and limit switch works
How to test and replace a Fan & Limit Control
The guy on youtube was helpful as well, and was quick to respond to my question.
So I am posting this for my own reference since this is a old furnace and may need more work in the future. This way there is a history I can look at. Thanks to all those that posted.
I also got some other good links that will be helpful for folks with my similar situation ...
How the Honeywell fan and limit switch works
How to test and replace a Fan & Limit Control
The guy on youtube was helpful as well, and was quick to respond to my question.
So I am posting this for my own reference since this is a old furnace and may need more work in the future. This way there is a history I can look at. Thanks to all those that posted.
#53
08-05-15, 07:38 AM
Dang! Still No Blower!!!
Well sir ... I got the new fan and replaced it, but the motor still won't come on. However this time there is power reaching the motor so it looks like both parts need to be replaced unless I'm missing something????
#54
08-05-15, 07:59 AM
Group Moderator
At the motor you need to use a meter to check from the hot wire which should be black to the neutral wire which should be white.
You must use a meter since you need to be sure you have hot and neutral.
If you confirm you have 120vac on those two wires.... then your motor is bad.
You must use a meter since you need to be sure you have hot and neutral.
If you confirm you have 120vac on those two wires.... then your motor is bad.
Oh oh ...
#56
08-18-15, 12:30 PM
Well Arighty Then :)
Well sir ... the blower is 
again ... looks like it was the fan switch and the blower motor that was bad ... well at least I will have heat this winter. Thanks for all the help.
again ... looks like it was the fan switch and the blower motor that was bad ... well at least I will have heat this winter. Thanks for all the help.
