GE 1hp ECM blower motor module

[MacMcMacmac]

Trying to fix a non operational GE furnace blower motor for a friend. I found a faulty thermistor in the ecm motor control board and I am going to swap it out. $10 component VS $1000-$2500 motor replacement. The furnace is a Carrier Weathermaker Infinity. It is 22 years old. Repairmen are mostly trying to sell my friend a new furnace for $4k installed. Probably the smart choice but she is someone of very limited means. Anyone ever do this themselves? The motor has been superseded. The newer motor has identical characteristics. I was wondering if I could remote mount the controller module for it and run a three wire pigtail to the motor if it doesn't physically fit on the end of the motor. Googling the thermistor part number gets me several hits for the exact same problem and solution. It would be a huge load off my friend's mind if I can make this work. Motor phases all ohm out to 4.7ohms, so the motor windings seem good. infinite resistance to case ground. Is the failed thermistor a cause or a symptom?

 

[dogdog]

Might be a thermal fuse if it is on the motor winding... you sure it's a thermistor ?

The differences is

Thermal fuse opens when heated to a certain temp and resets ("closes") when it is cool down to normal (most are auto reset, not all). and this is found in most cheaper motors as protection...and they do fail after some cycle of opening and close... so... you as long as you know the right temp range , you can get other brands. if you wanted to test, you can just place a ohm meter between the two end of the thermal fuse if it reads 0 its good reads open then bad. This was a $3 or under $5 item for my coffee grinder.

Thermistor changes resistances with temperature..... usually found on circuit broads as a mean of control and temp detection...

Oh right then there is that insurances thing.... so... just want to mention that.

 

[brewchief]

I've heard of guys fixing the module like that, if you have the time and ability to do it yourself it shouldn't be a problem.

A 22 year old carrier has a pretty decent chance of a failed secondary heat exchanger and/or cracks in the primary heat exchanger, we replace a lot of those vintage carrier and Bryant furnaces and more have bad heat exchangers then good.

Sent from my SM-T510 using Tapatalk

 

[danski0224]

Probably crappy ductwork and/or purple 3M filters causing the motor to over amp...

Should be a couple of terminals to install a regular PSC blower motor if funds really are an issue. I'm assuming that the cell phones and cable TV has been given up to make ends meet...

 

[Bert_]

Probably crappy ductwork and/or purple 3M filters causing the motor to over amp...

Should be a couple of terminals to install a regular PSC blower motor if funds really are an issue. I'm assuming that the cell phones and cable TV has been given up to make ends meet...

Motor will not over amp because of restrictive ductwork or a plugged filter.

Blocking airflow LOWERS the amps and load on the blower.

 

[Innovate1]

Motor will not over amp because of restrictive ductwork or a plugged filter.

Blocking airflow LOWERS the amps and load on the blower.

No, it doesn't. The power will go up for most ECM motors if the airflow is restricted. I deal with these motors. They detect airflow indirectly from speed and load and ramp up speed if the output is blocked to keep nearly constant airflow and the power goes UP. There is a limit for power output so they may not technically "over amp" (however you define that) but the load does go up.

What you are saying is correct for a constant speed motor like an induction motor for an air blower or centrifugal pump. Blocking the outlet restricting flow causes the power to drop. Blower units with those type motors sometimes come with warnings not to run them with no ductwork attached because it will overload the motor.

 

[Showkey]

So crappy ductwork took 22 years for cause a motor problem to show up ????

I have a similar furnace Bryant 23 years old.........have an eBay ECM blower motor sitting right next to the unit.

4-5 years ago I was experience a “rough start” discussed here at length......Two or three Comments were centered around the heat exchanger and how bad they were. Turned out it was rust in the burner tube cross over slots. Point is these units appear to be pretty not sure the exchanger plays any part other when it fails the unit would be replaced because of age.

Also mine has zone controlled dampers to heat or cool main living vs bedrooms areas to different temperatures. So the ECM blower in my case does not seem to care over the Last 23 years if the both main trunks are open or one or the other main trunks are completely blocked off by the dampers.

 

[danski0224]

So crappy ductwork took 22 years for cause a motor problem to show up ????

Why not?

Back problems (typically) don't show up after just one incident.

Might have been a power surge too.

Could be that the motor has had enough of a 3M filter left in for 180 days because it should last more than 90, right?

Who knows.

But if the TESP is over 0.5" WC (or whatever the fan is rated at), odds are that it IS drawing more power than it would if the same airflow could be delivered at 0.5" WC. Even in your system.

 

[bonneyman]

Is this what part you're referring to? I've heard of alot of repairs with this kit that solves the issue.

http://www.zebrahvac.com/VZREP.php

 

[MacMcMacmac]

Is this what part you're referring to? I've heard of alot of repairs with this kit that solves the issue.

http://www.zebrahvac.com/VZREP.php

I replaced just the thermistor and now the furnace is running normally again. It was a $5.40 component, so I bought 2 in case I have to do it again. Apparently, these parts get replaced often enough that the local electronics store keeps a 30A and a 20A version in stock. 30A for the furnace guys, 20A for the pool guys, he said.

The furnace is now operating normally, but the rightmost flame seems to be impinging on the end of the heat exchanger a bit instead of burning smartly down through the tube, so I told her to get her HVAC guy back in to look at it, since I'm not touching anything on the gas side. Flame seems a bit too energetic, like the gas flow or pressure is too high on that nozzle.

 

[MacMcMacmac]

So crappy ductwork took 22 years for cause a motor problem to show up ????

I have a similar furnace Bryant 23 years old.........have an eBay ECM blower motor sitting right next to the unit.

4-5 years ago I was experience a “rough start” discussed here at length......Two or three Comments were centered around the heat exchanger and how bad they were. Turned out it was rust in the burner tube cross over slots. Point is these units appear to be pretty not sure the exchanger plays any part other when it fails the unit would be replaced because of age.

Also mine has zone controlled dampers to heat or cool main living vs bedrooms areas to different temperatures. So the ECM blower in my case does not seem to care over the Last 23 years if the both main trunks are open or one or the other main trunks are completely blocked off by the dampers.

Hmm, i'm having intermittent rough starts on my Rheem Classic 90 Plus. Gets my attention. It's 20 years old now.

 

[Showkey]

Hmm, i'm having intermittent rough starts on my Rheem Classic 90 Plus. Gets my attention. It's 20 years old now.

Mine was inconsistent lighting, I played with it for hours. The flame sensor and igniter were checked and rechecked. Finally called a “professional” .......we got to duplicate the problem........he spent hours with no change. He increased the gas pressure that made it light more consistent.......but......it would boom on some starts when it was slow to light. He was thinking gas valve. But had real doubts.....me too.

The tech called the boss after hours of troubleshooting. The boss scratched his head tried different things we had already done. They has put in two igniter as guess ........Called tech support They were little help............then said I think it’s the burners. Specifically the burner cross over slots. He said remembered this issue from years back. He cleaned the burners all good, ordered the new burners, came back and installed the burners. He charged $200 for all the time and parts.........we should have done better.

The burners did not look the at bad for being 20 years old. There’s a thread on my issue and the resolution. A few others professionals confirmed they had seen burner rust and corrosion in the cross over slots.

If you pull the burners to clean or inspect......be careful as it’s very easy to damage or crack the igniter. The slants can not really be seen or inspected without pulling the burner assembly.

 

[MacMcMacmac]

Mine was inconsistent lighting, I played with it for hours. The flame sensor and igniter were checked and rechecked. Finally called a “professional” .......we got to duplicate the problem........he spent hours with no change. He increased the gas pressure that made it light more consistent.......but......it would boom on some starts when it was slow to light. He was thinking gas valve. But had real doubts.....me too.

The tech called the boss after hours of troubleshooting. The boss scratched his head tried different things we had already done. They has put in two igniter as guess ........Called tech support They were little help............then said I think it’s the burners. Specifically the burner cross over slots. He said remembered this issue from years back. He cleaned the burners all good, ordered the new burners, came back and installed the burners. He charged $200 for all the time and parts.........we should have done better.

The burners did not look the at bad for being 20 years old. There’s a thread on my issue and the resolution. A few others professionals confirmed they had seen burner rust and corrosion in the cross over slots.

If you pull the burners to clean or inspect......be careful as it’s very easy to damage or crack the igniter. The slants can not really be seen or inspected without pulling the burner assembly.

Thanks. Gives me something to look for. Turns out, the HVAC guy who serviced the furnace, ac and installed the current water heater for the previous owner lives just a few doors away,