No air blowing through ducts troubleshooting - Split system please help?
#1
04-04-16, 09:42 PM
No air blowing through ducts troubleshooting - Split system please help?
Stuck on this step of troubleshooting. So I tested the two manual limit switches L350F and this happened. I cannot get either of the two switches to trip! Not sure what I'm doing wrong but, when the furnace is going, I test both sides with meter at the same time and they read zero. When I test them after the system shuts off, each side separately reads 24.5 BUT >>>> that is only when the system shuts off :/ every other time I test they read zero. Symptoms with my system are: no air blows through ducts. Thermostat replaced, fan motor runs, burners ignite, whole system shuts down after 45 seconds after turning heat and fan on. (was previously told sensor might need cleaning or replacement... did that ... problem still happening) Fan motor sounds like it's runnning fine. All registers clean and inspected for blockage. Air return inspected and looks fine. The furnace light code is telling me there is a limit circuit open? Any ideas or suggestions on what to check next? HVAC guy said he thinks my control board is bad?!!!>??? I have a split system Goodman 10 years no probs then suddenly quit blowing air. :/ Am I crazy for thinking I'm supposed to be able to manually trip a manual limit switch while the system is running or??? Can't figur out why they won't trip. Could they BOTH be stuck?
#2
04-04-16, 09:51 PM
Group Moderator
Welcome to the forums.
Logged in, present and accounted for.
Your burner would not be running if you had a limit switch problem.
There are two fans on your furnace.... a draft inducer which runs with the burner and the blower that moves thru the house.
I could use the model number of the Goodman furnace. It can be found on the inside wall near the burner.
Logged in, present and accounted for.
Your burner would not be running if you had a limit switch problem.
Thermostat replaced, fan motor runs, burners ignite, whole system shuts down after 45 seconds after turning heat and fan on
I could use the model number of the Goodman furnace. It can be found on the inside wall near the burner.
#3
04-04-16, 10:19 PM
Burner would not run? oooohhhh... very interesting Also, good to know! I apologize, I should have included the model number in my original post. MBA 060 NH3RX 1/3 hp Consolidated Industries. Please forgive me if it seems to take me a minute. I'm only 5 ft 110 lbs and have to climb a rickety 6 ft ladder to access the furnace in my attic .... AND I'm a girl :P >>> who hates spiders lol. The reason I thought differently about the limit switches, is this video on youtube https://www.youtube.com/watch?v=HPckgHIwiTY The guy tests the same switch I have, while his system is on ... just like mine. However, he is able to trip the manual switch, but mine won't budge 
Could it be stuck open? Thus the reason the system shuts down after 45 seconds? And the reason my warning light says 'limit circuit open' ? Two fans? >>> I honestly had NO idea :X
Also, good to know! I apologize, I should have included the model number in my original post. MBA 060 NH3RX 1/3 hp Consolidated Industries. Please forgive me if it seems to take me a minute. I'm only 5 ft 110 lbs and have to climb a rickety 6 ft ladder to access the furnace in my attic .... AND I'm a girl :P >>> who hates spiders lol. The reason I thought differently about the limit switches, is this video on youtube https://www.youtube.com/watch?v=HPckgHIwiTY The guy tests the same switch I have, while his system is on ... just like mine. However, he is able to trip the manual switch, but mine won't budge 
Could it be stuck open? Thus the reason the system shuts down after 45 seconds? And the reason my warning light says 'limit circuit open' ? Two fans? >>> I honestly had NO idea :X
#5
04-04-16, 10:38 PM
Group Moderator
Ok.... so the furnace is not a Goodman. You mentioned that in your first post. The A/C condensor outside could be a Goodman.
I'm not familiar with this furnace and I'm not finding any technical info on it. I'm not seeing positive responses about the quality either. This may be a tough repair for me to help you with.
The sensor they were testing in that video was the flame rollout switch. That is not your problem. If that switch tripped it would not reset by itself.
This is what should happen based on what I'm seeing....
The thermostat calls for heat.
The draft inducer starts up. (that's the little blower on the front of the furnace)
The electronic ignition starts to spark.
The pilot lights and the spark stops.
The main burner lights.
After 30 or so seconds the main blower should come on.
If any limits were open..... the burner would not light. A limit could open after the burner was lit causing the burner to shut down. If the blower did not start the furnace would overheat causing a limit to open.
After reading this.... can you add anything or let me know what is failing ?
I'm not familiar with this furnace and I'm not finding any technical info on it. I'm not seeing positive responses about the quality either. This may be a tough repair for me to help you with.
The sensor they were testing in that video was the flame rollout switch. That is not your problem. If that switch tripped it would not reset by itself.
This is what should happen based on what I'm seeing....
The thermostat calls for heat.
The draft inducer starts up. (that's the little blower on the front of the furnace)
The electronic ignition starts to spark.
The pilot lights and the spark stops.
The main burner lights.
After 30 or so seconds the main blower should come on.
If any limits were open..... the burner would not light. A limit could open after the burner was lit causing the burner to shut down. If the blower did not start the furnace would overheat causing a limit to open.
After reading this.... can you add anything or let me know what is failing ?
#6
04-04-16, 10:51 PM
Nice to meet you Pete. You are right. Once again I must apologize for mistakenly assuming the whole system was manufactured by Goodman. That IS the AC condensor outside :P The furnace panel says Quatro? Since you mentioned there are two fans, now I'm questioning what I posted before about the fan seemingly running. I'm not sure if it IS actually the fan or the blower? This may sound like a dumb question but, how do I tell which one is which?
#7
04-04-16, 10:54 PM
Oh no! I don't mean to keep you up this late! I just realized you're in NJ! You should be in bed. We can continue this troubleshooting again tomorrow, if that works better?
#8
04-04-16, 11:12 PM
Group Moderator
Just getting ready to sign off.
The main blower that moves air thru the house sounds like the problem. You should be able to turn it on by putting the thermostat in FAN ON mode.
When you use the A/C..... the thermostat tells the blower to turn on.
When you use the heat.... the blower is controlled from a timer board. It turns on XX seconds after the burner lights and turns off XX seconds after the burner turns off.
We need to confirm if that main blower is working at all.
The main blower that moves air thru the house sounds like the problem. You should be able to turn it on by putting the thermostat in FAN ON mode.
When you use the A/C..... the thermostat tells the blower to turn on.
When you use the heat.... the blower is controlled from a timer board. It turns on XX seconds after the burner lights and turns off XX seconds after the burner turns off.
We need to confirm if that main blower is working at all.
#9
04-05-16, 12:37 PM
I must not be using the correct terminology. Let me start over. This is what the system does when I turn the thermostat to "heat" and the fan to the "on" position...
The thermostat calls for heat
I'm not sure what the draft inducer looks like but, the only motor I can see ... which sits to the left of the main burner, turns on (I was calling this the fan motor in my previous posts)
The electronic ignition sparks
The pilot lights
The main burner lights.
After approx 45 seconds the system completely shuts off giving me an error "limit circuit open"
Air is not moving through the ducts at all, which certainly leads me to believe what you call the 'main blower' is not turning on. I did not know there were two different parts ... one called a 'blower' and one called a 'fan'. I just thought there was a 'fan' which moved air through the ducts, and thus I've been referring to this part as the 'fan'. Thanks for clearing this up for me
Obviously something is causing the system to shut down, I'm assuming the limit switch is shutting everything down as a security, since the 'main blower' never comes on?
I was attempting to test the two limit switches "L350F", as I explain in my original post. Then I hit a roadblock, when I was not able to properly test the switches. The HVAC video I referred to was demonstrating how to test a 'limit switch'. I wanted to make sure they were both working properly, as that would be the next logical step in troubleshooting the system. So I thought :/ I was unable to determine if either switch works properly with a voltmeter, since I could not get them to 'trip' manually. They are supposed to be manual limit switches. Part number L350F. Here is the exact part I'm trying to test... Limit Switch Thermostat L350F for Goodman Amana Furnace 10123532 101235 32 | eBay I was getting a good reading of "00.0" while testing both of the limit switch's sides/terminals simultaneously, however, I could not get a reading on the switch while 'tripped'.
I don't know what to check next, so if you have any suggestions, I would greatly appreciate your help
The thermostat calls for heat
I'm not sure what the draft inducer looks like but, the only motor I can see ... which sits to the left of the main burner, turns on (I was calling this the fan motor in my previous posts)
The electronic ignition sparks
The pilot lights
The main burner lights.
After approx 45 seconds the system completely shuts off giving me an error "limit circuit open"
Air is not moving through the ducts at all, which certainly leads me to believe what you call the 'main blower' is not turning on. I did not know there were two different parts ... one called a 'blower' and one called a 'fan'. I just thought there was a 'fan' which moved air through the ducts, and thus I've been referring to this part as the 'fan'. Thanks for clearing this up for me
Obviously something is causing the system to shut down, I'm assuming the limit switch is shutting everything down as a security, since the 'main blower' never comes on?
I was attempting to test the two limit switches "L350F", as I explain in my original post. Then I hit a roadblock, when I was not able to properly test the switches. The HVAC video I referred to was demonstrating how to test a 'limit switch'. I wanted to make sure they were both working properly, as that would be the next logical step in troubleshooting the system. So I thought :/ I was unable to determine if either switch works properly with a voltmeter, since I could not get them to 'trip' manually. They are supposed to be manual limit switches. Part number L350F. Here is the exact part I'm trying to test... Limit Switch Thermostat L350F for Goodman Amana Furnace 10123532 101235 32 | eBay I was getting a good reading of "00.0" while testing both of the limit switch's sides/terminals simultaneously, however, I could not get a reading on the switch while 'tripped'.
I don't know what to check next, so if you have any suggestions, I would greatly appreciate your help
#10
04-05-16, 12:42 PM
Group Moderator
Ok.... stop worrying about the limit switches. They are working fine. You just told me that.
Your furnace is overheating because the main blower is not working. I mentioned this in post 8. You need to see if the blower works at all. If your thermostat has a FAN ON position..... try that. If not.... try the A/C and see if the blower runs then.
It's either a control problem or a motor problem. It could be a defective capacitor on the blower motor. Let me know if the blower runs at all.
Your furnace is overheating because the main blower is not working. I mentioned this in post 8. You need to see if the blower works at all. If your thermostat has a FAN ON position..... try that. If not.... try the A/C and see if the blower runs then.
It's either a control problem or a motor problem. It could be a defective capacitor on the blower motor. Let me know if the blower runs at all.
#11
04-05-16, 12:48 PM
A little more info... the blower is not blowing air through the ducts at all. Meaning... It does not matter how I set the thermostat. i.e. AC = not blowing air. Fan only = not blowing air. Heat + Fan = not blowing air. Auto = not blowing air. Temporary setting "hold" = not blowing air.
#12
04-05-16, 01:33 PM
lol ok ... reason I was adamant about testing those switches ...
(a) The timer control board error light "limit circuit open"
(b) I was assuming they had a part in operating the "fan" properly, since I understood the 'F' in the part number referred to the 'fan' and the 'L' to the 'limit'.
(c) I had no idea there were two parts i.e. 'fan' and 'blower' ... I just thought there was a fan period.
(d) I do not know how to locate the blower because the rest of the furnace housing does not look accessable. Thus I could only state what I was able to see?
Can you explain how I know the switches work, since I somehow keep telling you they do? I'm just confused about how I keep telling you that they are working fine. lol Then I won't bring them up again. I understand the furnace is overheating. I just don't know what to test next, since I could only test what I could see?
(a) The timer control board error light "limit circuit open"
(b) I was assuming they had a part in operating the "fan" properly, since I understood the 'F' in the part number referred to the 'fan' and the 'L' to the 'limit'.
(c) I had no idea there were two parts i.e. 'fan' and 'blower' ... I just thought there was a fan period.
(d) I do not know how to locate the blower because the rest of the furnace housing does not look accessable. Thus I could only state what I was able to see?
Can you explain how I know the switches work, since I somehow keep telling you they do? I'm just confused about how I keep telling you that they are working fine. lol Then I won't bring them up again. I understand the furnace is overheating. I just don't know what to test next, since I could only test what I could see?
#14
04-05-16, 01:53 PM
I know you said this in your first reply...
"There are two fans on your furnace.... a draft inducer which runs with the burner and the blower that moves thru the house."
It was late last night and I was tired. I'm just a mom(an only parent) who is a Libra. My biggest fault is my need to exhaust all avenues of "fix it yourself" before I dole out money for something I could have fixed on my own. It's what brought me here in the first place. Try to keep in mind I have never worked on HVAC prior to this adventure. I'm sorry if it takes me a while to 'get' it lol.
"There are two fans on your furnace.... a draft inducer which runs with the burner and the blower that moves thru the house."
It was late last night and I was tired. I'm just a mom(an only parent) who is a Libra. My biggest fault is my need to exhaust all avenues of "fix it yourself" before I dole out money for something I could have fixed on my own. It's what brought me here in the first place. Try to keep in mind I have never worked on HVAC prior to this adventure. I'm sorry if it takes me a while to 'get' it lol.
#15
04-05-16, 02:20 PM
This is the part I ordered...
Honeywell ST9120U1011
I'm understanding this to be the main circuit board to the furnace. Some call it a 'timer control' some call it a 'main furnace control module'. The correct nomenclature.... basically a moot point.... because it is the only circuit board on the furnace. From what I can see, it controls pretty much everything on the furnace.
I was just wanting to make sure all other visible parts were working properly, like switches, wiring etc... while waiting for the part I ordered to be delivered. So I started to test what I could see. Simply because with my luck, I'd get the expensive part (control board) only to discover an additional $10 part should have been replaced first. Make any sense? I know it sounds like I'm going backwards, but I'm really not. I had the HVAC tech help me narrow down the issue, however, I'm one who has been misled by "pros" in the past! This is what caused me to want to verify what he was telling me by testing/troubleshoorting the other visible parts on my own.
Honeywell ST9120U1011
I'm understanding this to be the main circuit board to the furnace. Some call it a 'timer control' some call it a 'main furnace control module'. The correct nomenclature.... basically a moot point.... because it is the only circuit board on the furnace. From what I can see, it controls pretty much everything on the furnace.
I was just wanting to make sure all other visible parts were working properly, like switches, wiring etc... while waiting for the part I ordered to be delivered. So I started to test what I could see. Simply because with my luck, I'd get the expensive part (control board) only to discover an additional $10 part should have been replaced first. Make any sense? I know it sounds like I'm going backwards, but I'm really not. I had the HVAC tech help me narrow down the issue, however, I'm one who has been misled by "pros" in the past! This is what caused me to want to verify what he was telling me by testing/troubleshoorting the other visible parts on my own.
#16
04-05-16, 02:31 PM
HVAC tech wants to charge me over $400.00 part included. I already paid him $150. for the service call. If I can buy the same part for $70 brand new and replace it myself, that's what I'd prefer to do. I already removed the controller after he left on my own anyway. I wanted to open it and check to make sure it wasn't just a blown fuse. Some of these have fuses. I didn't want the tech to think I was insulting his ability by questioning everything so, I decided to hold off on the repair until I had more time to check everything on my own. You ever watch "To Catch a Contractor"? That's what I'm usually dealing with out here simply because of my gender.
Know waddamean?
Know waddamean?
#17
04-05-16, 05:36 PM
Group Moderator
I'm having a little trouble following you.
You have two blowers on your furnace. One is near the burner. It runs just before the burner lights. It's called a draft inducer blower. (inducer for short) It's a little round black unit. It blows the hot exhaust gases out the flue. It's the first thing to start on a call for heat. If it doesn't start- no burner.
The second blower is the one that moves the air thru the house. It will be located in a compartment between the burner and the return ductwork.
I thought I went over this pretty well..... if ANY limit switches are open, tripped or defective... the burner WILL NOT light.... period. Your furnace is lighting AND THEN tripping a limit switch because it's overheating. Once the furnace overheats there will be a temporarily open limit switch and it will result in a trouble code. After the furnace cools off..... the limit will reset and the furnace will be able to re-light.
I'm not sure what your tech did there. At this point we know the main blower is not working. It can be one of several problems.... I'll list them again in order of likelihood.
1) Defective blower motor capacitor
2) Defective blower motor
3) Defective control board.
Accessing the blower motor in the attic is not easy. What needs or was needed to be done at this point is to check for 120vac out of the control board to the blower motor. If the voltage is present.... the blower motor is bad. If there is no voltage.... the board is bad.
You have two blowers on your furnace. One is near the burner. It runs just before the burner lights. It's called a draft inducer blower. (inducer for short) It's a little round black unit. It blows the hot exhaust gases out the flue. It's the first thing to start on a call for heat. If it doesn't start- no burner.
The second blower is the one that moves the air thru the house. It will be located in a compartment between the burner and the return ductwork.
I thought I went over this pretty well..... if ANY limit switches are open, tripped or defective... the burner WILL NOT light.... period. Your furnace is lighting AND THEN tripping a limit switch because it's overheating. Once the furnace overheats there will be a temporarily open limit switch and it will result in a trouble code. After the furnace cools off..... the limit will reset and the furnace will be able to re-light.
I'm not sure what your tech did there. At this point we know the main blower is not working. It can be one of several problems.... I'll list them again in order of likelihood.
1) Defective blower motor capacitor
2) Defective blower motor
3) Defective control board.
Accessing the blower motor in the attic is not easy. What needs or was needed to be done at this point is to check for 120vac out of the control board to the blower motor. If the voltage is present.... the blower motor is bad. If there is no voltage.... the board is bad.
#18
04-06-16, 08:20 PM
Yeah, it's not the first time I've been told I'm hard to follow ... no worries 
Thanks for hanging in there with me Pete! Yes, I'm an idiot... because I think the only way I would have understood what you've been trying to tell me ALL ALONG, was only if you had said "Hey Sails, of course you're getting the error code "limit circuit open" when it fails dummy, because whatever is wrong >>> is causing the limit switch to open and shut your system down knucklehead!" Well dagnabbit then! Why in the bleep is it designed to give me a code that really doesn't point me to the actual issue?? I thought the key was supposed to help guide me to the problem!~ Not just an alert!! :/ I already KNOW there's a problem. Geeeeezzz pfff Ok, deep breath ... counting to ten, ohmmm... frustration released... Zen again....lol <just ignore that rant. So, furnace control board/brain, is NOT smarter than me. No sir, it is not!!! Although... I was secretly hoping it was
Just like you said "blower not working." I'll plug the board back in and test the 120vac out of the board as suggested (likely what the tech did as well). Thank the LORD above, perhaps I didn't just throw away $150 of my hard earned money. Maybe the tech WAS actually being honest with me. That'd be a nice change. I'll let you know the verdict Thanks for your patience Pete! It's people like you, who allow me to think it might be possible for me to finally get the furnace functioning properly again, without filing for bankruptcy. I may be able to actually get some sleep now .... You people are fabulous! 
btw, quite alot of views on this thread in just 2 days
Thanks for hanging in there with me Pete! Yes, I'm an idiot... because I think the only way I would have understood what you've been trying to tell me ALL ALONG, was only if you had said "Hey Sails, of course you're getting the error code "limit circuit open" when it fails dummy, because whatever is wrong >>> is causing the limit switch to open and shut your system down knucklehead!" Well dagnabbit then! Why in the bleep is it designed to give me a code that really doesn't point me to the actual issue?? I thought the key was supposed to help guide me to the problem!~ Not just an alert!! :/ I already KNOW there's a problem. Geeeeezzz pfff Ok, deep breath ... counting to ten, ohmmm... frustration released... Zen again....lol <just ignore that rant. So, furnace control board/brain, is NOT smarter than me. No sir, it is not!!! Although... I was secretly hoping it was
Just like you said "blower not working." I'll plug the board back in and test the 120vac out of the board as suggested (likely what the tech did as well). Thank the LORD above, perhaps I didn't just throw away $150 of my hard earned money. Maybe the tech WAS actually being honest with me. That'd be a nice change. I'll let you know the verdict
Thanks for your patience Pete! It's people like you, who allow me to think it might be possible for me to finally get the furnace functioning properly again, without filing for bankruptcy. I may be able to actually get some sleep now .... You people are fabulous! 
btw, quite alot of views on this thread in just 2 days
#19
04-06-16, 08:50 PM
Group Moderator
No problem.
Based on the board you said your furnace uses I marked the control board where you'll find the blower wiring. I used red to show HEAT and blue to show COOL. Those may not be the colors you'll find there. The location on the board is labeled. The neutral will appear on one of the gray terminals. Measure from neutral to COOL and neutral to HEAT.
When you do the testing..... put the thermostat in FAN ON mode. I believe you should find power on the cool terminal.
Careful as there is a 120VAC there.
Based on the board you said your furnace uses I marked the control board where you'll find the blower wiring. I used red to show HEAT and blue to show COOL. Those may not be the colors you'll find there. The location on the board is labeled. The neutral will appear on one of the gray terminals. Measure from neutral to COOL and neutral to HEAT.
When you do the testing..... put the thermostat in FAN ON mode. I believe you should find power on the cool terminal.
Careful as there is a 120VAC there.
#20
04-06-16, 10:07 PM
Awwwww
Thanks for including the image! That was so thoughtful of you. It will be a tremendous help to me I'll try to get back up there in the next few days to test. If a week or so passes and you never hear back, send for help please I most probably fried myself somehow, and I don't want my little dogs to starve to death wondering what happened to mom. ouch
Thanks for including the image! That was so thoughtful of you. It will be a tremendous help to me
I'll try to get back up there in the next few days to test. If a week or so passes and you never hear back, send for help please I most probably fried myself somehow, and I don't want my little dogs to starve to death wondering what happened to mom. ouch
#21
04-15-16, 08:52 PM
ok so I'm back & I didn't even fry myself ... yay 
! I finally was able to locate the access door for the blower compartment. After further testing, I discovered the blower motor was bad. I removed blower assy. Removed old motor from housing and took it to HVAC parts supply shop. Got the new motor home and mounted it inside housing. Hit a road block 
There are 2" long screws on the bottom of the motor, which are too long to allow the blower wheel to turn freely because they are butting up against it, when the motor is mounted. Am I supposed to snap them off shorter or is it possible I may have picked up the wrong replacement motor? Everything seems to match up as far as wiring, voltage, speed, hp etc. The only difference I can see is the new motor says "continuous air over" and the old says "4SPD duty air over" Just wondering if the screws are purposely long to help protect motor shaft during transport perhaps and therefore commonly snapped off before mounting? The old motor's screws are 1.5" shorter.
I'd hate to snap them and then find out later this is actually not the correct motor.
Old motor manufacturer = A.O.Smith - Model# F48F93B22
Old motor part# 4101101 or # 407460
New motor manufacturer = MARS - Model# 10585
New motor part# Y7L623C512S
I wish I could figure out how to post images on here, so I can show exactly what I'm describing
! I finally was able to locate the access door for the blower compartment. After further testing, I discovered the blower motor was bad. I removed blower assy. Removed old motor from housing and took it to HVAC parts supply shop. Got the new motor home and mounted it inside housing. Hit a road block 
There are 2" long screws on the bottom of the motor, which are too long to allow the blower wheel to turn freely because they are butting up against it, when the motor is mounted. Am I supposed to snap them off shorter or is it possible I may have picked up the wrong replacement motor? Everything seems to match up as far as wiring, voltage, speed, hp etc. The only difference I can see is the new motor says "continuous air over" and the old says "4SPD duty air over" Just wondering if the screws are purposely long to help protect motor shaft during transport perhaps and therefore commonly snapped off before mounting? The old motor's screws are 1.5" shorter.
I'd hate to snap them and then find out later this is actually not the correct motor.
Old motor manufacturer = A.O.Smith - Model# F48F93B22
Old motor part# 4101101 or # 407460
New motor manufacturer = MARS - Model# 10585
New motor part# Y7L623C512S
I wish I could figure out how to post images on here, so I can show exactly what I'm describing
#22
04-15-16, 09:16 PM
Group Moderator
It's so hard to match motors. I don't have the books here but from what I can see it looks like the motors are interchangeable but in the pictures.... it looks like the AO Smith motor comes with longer bolts. It is very possible that you will have to cut them as this is a universal replacement motor.
Did the new motor come with its matching capacitor ?
Here is a link for posting pictures. If you use a phone you will have to resize the pictures smaller to be able to post here. It's explained here... http://www.doityourself.com/forum/el...-pictures.html
Did the new motor come with its matching capacitor ?
Here is a link for posting pictures. If you use a phone you will have to resize the pictures smaller to be able to post here. It's explained here... http://www.doityourself.com/forum/el...-pictures.html
#23
04-15-16, 09:32 PM
Hey Pete Thanks!
Yeah they just seem a tiny bit different, but nothing that looks like a problem except the screws being in the way. There's just not a lot of free space in between where the motor is seated and the wheel. I went ahead and bought a new capacitor, when I picked up the motor... since the new motor calls for 5 MFD 370 VAC and the old was 7.5 MFD 370 VAC
Here's a link to a photo of what the NEW motor's screws look like....
Replacement Motor matching AO SMITH Number F48F93B22
And a link to what my OLD motor's screws looks like....
http://www.amazon.com/gp/product/B00...d_bhz_bw_c_x_1
I guess I'll go ahead and cut them shorter tomorrow and hope for the best? Hopefully I won't screw this up :/
Yeah they just seem a tiny bit different, but nothing that looks like a problem except the screws being in the way. There's just not a lot of free space in between where the motor is seated and the wheel. I went ahead and bought a new capacitor, when I picked up the motor... since the new motor calls for 5 MFD 370 VAC and the old was 7.5 MFD 370 VAC
Here's a link to a photo of what the NEW motor's screws look like....
Replacement Motor matching AO SMITH Number F48F93B22
And a link to what my OLD motor's screws looks like....
http://www.amazon.com/gp/product/B00...d_bhz_bw_c_x_1
I guess I'll go ahead and cut them shorter tomorrow and hope for the best? Hopefully I won't screw this up :/
#24
04-16-16, 05:31 PM
Sorry about my links in my last reply
Let me try uploading a few photos 
Below = Two photos of new motor
Below = Two photos of old motor
See how crazy long the screws on the new motor are?
I do plan to cut them in a minute, but I thought I'd try my luck at uploading photos and ask what the hay these metal rings that came in the box are supposed to be for??? They seem to be about the same size as the collar/bushing that's around the bottom of the motor shaft? Spacers or something?
Let me try uploading a few photos 
Below = Two photos of new motor
Below = Two photos of old motor
See how crazy long the screws on the new motor are?
I do plan to cut them in a minute, but I thought I'd try my luck at uploading photos and ask what the hay these metal rings that came in the box are supposed to be for??? They seem to be about the same size as the collar/bushing that's around the bottom of the motor shaft? Spacers or something?
#25
04-16-16, 09:05 PM
I crimped connectors on all the wires, cut the screws, mounted the motor onto the bracket and the bracket onto the blower housing, balanced the wheel and motor so that the wheel spins perfectly (this took me some time), hoisted the unit 12ft off the ground up into my attic (it's heavy), installed the new capacitor, installed the entire assembly back into the furnace housing, threaded the wiring through the access panel, connected all of the wiring to the control board and THEN ... right before I was about to climb back down and turn on the breakers to start it up and see if it worked, I first double checked my notes and suddenly realized I completely overlooked the fact that this new motor DOES NOT have a 'white neutral' wire!!!!!
Am I completely screwed? Do I have to start over?
I'm afraid to even turn it on now
#26
04-16-16, 09:08 PM
Group Moderator
You posted a pic of the Mars motor. I need another pic of the wiring diagram..... the right side of the label. I can't find the wiring online.... unless you have it on a sheet.
Last edited by PJmax; 04-16-16 at 09:24 PM.
#27
04-16-16, 09:35 PM
Hey Pete! Thank goodness you're here tonight! You're an absolute savior! Ok, I will upload photos of both wiring diagrams for both motors. I was wondering if it's possible to use the yellow wire as a substitute for the white? If not yellow, perhaps blue? Both yellow and blue wires on the new motor are just parked on 'unused' terminals on the control board.
Thank you so much for your help again!! I'd hate to have to start over from the drawing board, if there's any way I can avoid it.
Above = old motor
Below = new motor
Thank you so much for your help again!! I'd hate to have to start over from the drawing board, if there's any way I can avoid it.
Above = old motor
Below = new motor
#28
04-16-16, 09:37 PM
Group Moderator
Thanks for the picture. I'm embarrassed to not be able to find the wiring diagram online.
Anyway...... the yellow is the neutral and is used as the white wire.
By the way.... you're doing a great job.
Anyway...... the yellow is the neutral and is used as the white wire.
By the way.... you're doing a great job.
#29
04-16-16, 09:51 PM
Are you telling me you don't have all of this crazy bleeping wiring information right off the top of your head?!?!? LOL! I'm just thankful I took a photo before I started mounting the thing because I really did a number on the label getting it secured correctly into the bracket! Well, I think you may want to wait until I do a test run before you compliment my work... heehee To be honest, I'll be shocked if it EVER runs again after everything I've done to it 
Thanks again and thanks for the kudos ... I'll keep you posted. If you don't hear from me tonight, that means something went wrong and I had to stop, have a beer, and wait to begin again tomorrow because I'm about worn out
Thanks again and thanks for the kudos ... I'll keep you posted. If you don't hear from me tonight, that means something went wrong and I had to stop, have a beer, and wait to begin again tomorrow because I'm about worn out
#30
04-16-16, 10:10 PM
Group Moderator
#31
04-16-16, 10:40 PM
I can't even imagine how well you must be in your 'actual' field Pete, if you just kinda do this on the side!! Well, Mr. Expert DIY'er, I'm very happy to report GOOD NEWS!
I now have air blowing through my ducts again!!! I just turned the thermostat to fan only and voila ... there's my air! I didn't button everything completely up in the attic yet though. I'm gonna wait 'til tomorrow to do a complete run through the whole system.... because after all that, I'm pretty exhausted.
I really cannot thank you enough for all your help and patience I'm sure I'll be back soon with more questions, maybe even tomorrow lol. I hope you'll still be here giving out expert advice
I now have air blowing through my ducts again!!! I just turned the thermostat to fan only and voila ... there's my air! I didn't button everything completely up in the attic yet though. I'm gonna wait 'til tomorrow to do a complete run through the whole system.... because after all that, I'm pretty exhausted.
I really cannot thank you enough for all your help and patience
I'm sure I'll be back soon with more questions, maybe even tomorrow lol. I hope you'll still be here giving out expert advice
#32
04-16-16, 11:03 PM
Group Moderator
