N/A HVAC ECM blower motor not working

[FORANE]

We have a Goodman GSZC180601 2 stage, 5 ton system with a Goodman AVPTC61D14AC air handler. The air handler blower motor is a Goodman 0131M01011 ECM 1 ton motor. It was installed new in 2018 and has 10 year parts warranty. It ran perfectly until 3 months ago; we've been without AC for 3 months...

The ECM on cool will power on, squirrel cage rolls, then power off after about 3 seconds. This power on then off will repetitively happen for about 10 cycles then it throws a code B5 (blower motor rotor locked).

We have a couple HVAC guys who work together that have done a fair bit of work for us in the past. They said that meant the ECM module had failed. They ordered a new one under warranty. After getting the incorrect motor the first time and re-ordering, they installed it. No change in symptoms with new motor installed.

They said it is a communicating system and needed the communicating board 0130F00273S. That board is no longer available. No problem, a new board model is available BTSDL01. ok, buy the BTSDL01, install it, try to program my model AVPTC61D14AC, but closest option is AVPTC61D14A*. No change in symptoms with shared data uploaded to air handler board npcbja104.
Maybe the air handler board is bad. We changed it, twice. No change in symptoms with new board installed even after uploading shared data to it multiple times.

Blower motor is getting power. Board is getting 24v (it measured at 29v). Of note, the blower motor did come on and stay on when thermostat (Honeywell RTH9580WF) set to fan on only. Thermostat changed; no change in symptoms. Checked wire harness between the board and ECM; no issues found.

HVAC guy says he thinks the board isn't communicating with the ECM. He says it needs the old communicating board 0130F00273S and the new BTSDL01 will not work.

I spoke with another HVAC guy who wants to replace both the board and the ECM again but he's not sure if that will help. He tried calling the Goodman support line but said they didn't answer despite many calls. My other HVAC guy doesn't think Goodman will give him another warranty motor since they just gave him the other one.

Can this air handler be converted to a PSC motor given the condenser is a 2 stage system?
Ideas?

 

[GeorgeC]

The ECM on cool will power on, squirrel cage rolls, then power off after about 3 seconds. This power on then off will repetitively happen for about 10 cycles then it throws a code B5 (blower motor rotor locked).
...
Ideas?

I'm probably way off here, but this reminded me of our water heater. Natural gas, has a tank, but allegedly more efficient due to forced induction/no pilot light/etc. The blower motor comes on, and at some point later, the solenoid opens the gas, electric ignition does its thing, then whoomp, there it is.

At some point, it started cycling and failing to light, and percussive maintenance wasn't healing it anymore. It was under warranty, so I called the number, and the guy advised me to order a replacement pressure switch on Amazon. When the blower motor comes on, it's looking for a pressure drop (ObAviation: venturi effect!), to make sure that the flue is not obstructed.

Anyway, the replacement pressure switch did the job. Mostly. Now, it always takes exactly *two* attempts for it to light, but since $spousal_unit stopped complaining of cold showers, I stopped troubleshooting.

So, is there a round diaphragm thingy with two wires coming out of it? Try whacking it with the handle of a screwdriver.

 

[Racerx]

Sounds like you need a new HVAC tech.

I have a Goodman in the detached garage and on the rental. It doesn't actually sound like the blower motor is the problem if it begins to run and runs on fan. It sounds like a condenser issue.

I believe this error code is a locked rotor on the compressor, not the blower. First thing I'd check is make sure mice didnt gnaw on any wires on the condenser. Second thing would be to check to see if the capacitor hasn't gone tango uniform.

 

[FORANE]

Sounds like you need a new HVAC.

I have a Goodman in the detached garage and on the rental. It doesn't actually sound like the blower motor is the problem if it begins to run and runs on fan. It sounds like a condenser issue.

I believe this error code is a locked rotor on the compressor, not the blower. First thing I'd check is make sure mice didnt gnaw on any wires on the condenser. Second thing would be to check to see if the capacitor hasn't gone tango uniform.

You may be right. Now that you mention it, the capacitor for the outdoor motor did fail. I first noticed the condenser fan wasn't running. Replaced the capacitor for it and the outside unit appeared to be running fine. No error code on its board...

 

[FORANE]

When the blower motor comes on, it's looking for a pressure drop

Anyway, the replacement pressure switch did the job.

So, is there a round diaphragm thingy with two wires coming out of it? Try whacking it with the handle of a screwdriver.

Hey George

Thank you for your response. Don't think that's the issue. On ECM's the module accomplishes that role (I think). Despite my username and the fact that I'm EPA608 certified, I'm not a HVAC guy. The only round diaphragm in the air handler I'm aware of is limit switches.

 

[FORANE]

Sounds like you need a new HVAC tech.

I have a Goodman in the detached garage and on the rental. It doesn't actually sound like the blower motor is the problem if it begins to run and runs on fan. It sounds like a condenser issue.

I believe this error code is a locked rotor on the compressor, not the blower. First thing I'd check is make sure mice didnt gnaw on any wires on the condenser. Second thing would be to check to see if the capacitor hasn't gone tango uniform.

Agree regarding a new tech, but finding a good one seems challenging. I've paid for a number of service calls here in the past where the tech failed to solve the problem. Seems like the more technical these units become, the harder they are to service. No one I have spoken with has an ECM tester. I'd buy one but they don't seem to be available for this ECM. I found and downloaded the service manual for this unit; Goodman recommends the UTT-01 ECM tester but it appears to be on backorder everywhere.

I checked the compressor. Don't think that's the problem. The condenser board shows no error codes and indicated proper cycling between cool 1 and cool 2. Condenser fan works fine since capacitor changed months ago. Capacitor still good. Compressor starts up fine though I do hear some noise. Inside air handler A coil gets cold and eventually frosts due to inside blower motor failing to run properly.

Here's the error code list for this unit. B5 points to the blower motor.

 

[Racerx]

To me a locked blower motor rotor would mean the blower motor is getting some power but won't move. But yours works on fan, so to me it's not locked. And it could be one of those generic catch all codes. The only other time I've had issues, it's been a blown fuse in the air handler. Small little automotive style fuse. Mice chewed the wires outside by the condenser. Pops that fuse. I'll have heat, fan, no ac.

Sounds like a call to Goodman is in order.

Definitely right with these things becoming more technical. Dad had a new unit installed and what a nightmare that became trying to get it to work at all. Crap install, incorrect unit shipped, etc...he had a factory rep come out to troubleshoot and apologize because the factory/shipping messed up and installers didn't catch it.

 

[Checkout_my_Six]

It could be a bad winding in the motor....as it heats up the coil opens...or if there are run capacitors they do go bad.....just a thought.

Some say Goodman is crap....but, I purchased an older R-22 4 ton compressor on MarketPlace for $100 and replaced the 3 ton Rheem unit....kept the inside unit and A-coil. I did have to rewire the board in the outside unit. The reversing valve relay was backwards for everything inside....it's been going strong now for +7 years....and runs all day in the summer. I know one day it will quit....but it doesn't owe me anything.

 

[PaulMillner]

We have a Goodman GSZC180601 2 stage, 5 ton system with a Goodman AVPTC61D14AC air handler. The air handler blower motor is a Goodman 0131M01011 ECM 1 ton motor. It was installed new in 2018 and has 10 year parts warranty. It ran perfectly until 3 months ago; we've been without AC for 3 months...

The ECM on cool will power on, squirrel cage rolls, then power off after about 3 seconds. This power on then off will repetitively happen for about 10 cycles then it throws a code B5 (blower motor rotor locked).

We have a couple HVAC guys who work together that have done a fair bit of work for us in the past. They said that meant the ECM module had failed. They ordered a new one under warranty. After getting the incorrect motor the first time and re-ordering, they installed it. No change in symptoms with new motor installed.

They said it is a communicating system ... Can this air handler be converted to a PSC motor given the condenser is a 2 stage system?
Ideas?

You can always install a PSC motor, but the constraint here will be convincing the rest of the electronics to play along... brute force is to replace the control system with generic, but that seems ugly.

Paul

 

[Notrub]

Sound like a bad tech, possibly a bad thermostat(when weird things happen its always the thermostat someone’s painted or sanded?), and you should call goodmans technical support.


I like relays and capacitors no ordering parts because every tech keeps them on the truck and no computer to diagnose. The inside of a modern compressor fan housing is more complicated than my first pc in the 90s. It’s rather stupid to chase the minimal efficiency for the effort and complexity. Especially when it comes to repairing tech it’s disposable! Modules and computer boards.

Best of luck hope this helps definitely call the tech support

 

[FORANE]

I researched more about the system I have and found that the blower motor does not come on with thermostat on fan only. Not sure why the hvac guy thought that it did. On fan only it does the same start stop thing as it does on cool. Difference is on fan only after 10 start attempts it doesn't throw the b5 code, it throws a b6 code. b6 is over/under voltage trip or temperature trip.

The service manual https://hvacdirect.com/media/pdf/GSZC7 Service Manual New.pdf
on page 37 describes testing voltage. The ECM has high voltage power supplied at reading 236 v ac.
The low voltage between board and ECM is lower than spec on 2 of the 3 pin test locations. Not sure what that points to. These tests are dc voltage and with the ECM connected to the board. They don't read with the ECM disconnected so I can't isolate it to the board as the cause.

 

[Notrub]

Did you talk to goodman technical support? Your low voltage is really low a transformer gets the volts down to 24v dc this is used by the thermostat to pull in the relays that feed high voltage to the fan in the air handler and compressor and associated fan. High voltage 220-240ac low voltage 20-24dc. It’s amazing how complex they can be….best way to think of it low voltage pulls in the high voltage. Thermostat or low voltage transformer is my internet diagnosis. Even with mother boards modules and variable drives all you are doing is starting and running three electrical motors albeit with several sensors and valves.

 

[Checkout_my_Six]

I think you meant 24 VAC.....

 

[Notrub]

??Going off his manual which says vdc. Thanks for having my back as most are 24vac

 

[FORANE]

Did you talk to goodman technical support? Your low voltage is really low a transformer gets the volts down to 24v dc this is used by the thermostat to pull in the relays that feed high voltage to the fan in the air handler and compressor and associated fan. High voltage 220-240ac low voltage 20-24dc. It’s amazing how complex they can be….best way to think of it low voltage pulls in the high voltage. Thermostat or low voltage transformer is my internet diagnosis. Even with mother boards modules and variable drives all you are doing is starting and running three electrical motors albeit with several sensors and valves.

I haven't talked with Goodman tech support. It my understanding they wont provide support to homeowners directly, which is understandable. One of the techs I contacted locally attempted to contact Goodman tech support multiple times but couldn't get ahold of anyone; that is not understandable.

It my understanding the ECM gets 230v directly anytime the airhandler circuit breaker is powered on. I checked it and it is indeed getting that power; it comes into the ECM 5 pin plug. The low voltage transformer provides 24vac to the board; I checked it and indeed the board is getting 29vac. The ECM gets low voltage from the board on a 4 pin plug. According to the service manual, that voltage is supposed to be only 3.3 or 15 vdc depending on pins being tested. As I posted above, 2 of the 3 are lower voltage than they should be.

I changed the board twice; all 3 boards have the same vdc readings.
I changed the thermostat once; the other one did nto change the failure mode of the ECM.
I don't see a low voltage transformer that provides power to the ECM directly.
The techs that changed the ECM believe the board has incorrect shared data as the cause.
I have a 3rd tech tentatively scheduled to come look at it in a week.

 

[Doctor Bob]

I diagnose these ECM motors all day long. Been at it 28 years and counting. I’m starting to get the hang of it .

You are on the right track. The motors are always fed 240 volts ac.
The signals are in DC voltage and vary to tell it what speed to turn.
The computer on the motor talks to the computer board in the air handler.
By your voltage notations, it is not getting the signals to go.
Not familiar with the Goodman unit, per se, but it should be similar to all the other brands.
Diagnosing from afar is never the best route.
I never replace just the module on the motor. Only the whole motor and module as one unit.
Never had any issues you describe by replacing the entire motor/module combo.

Best of luck.

 

[FORANE]

Found and fixed the problem. One of the two breakers in the air handler was faulty. I still don't understand it. The motor was getting 230v, the board was powered, but when the breaker supplying power to them was replaced everything worked.

Thank you to those who contributed here.

 

[PaulS]

Probably unable to provide enough current

 

[SoonerAviator]

Found and fixed the problem. One of the two breakers in the air handler was faulty. I still don't understand it. The motor was getting 230v, the board was powered, but when the breaker supplying power to them was replaced everything worked.

Thank you to those who contributed here.

You had circuit breakers INSIDE the unit?

 

[FORANE]

You had circuit breakers INSIDE the unit?

The system has breakers in the main breaker box. It also has 2 breakers in the air handler cabinet. It was one of the air handler cabinet breakers.

 

[3393RP]

The system has breakers in the main breaker box. It also has 2 breakers in the air handler cabinet. It was one of the air handler cabinet breakers.View attachment 132821

That 50 amp breaker fed by 12 AWG wire is... interesting. What's the amperage of the panel breaker feeding that circuit?

 

[FORANE]

That 50 amp breaker fed by 12 AWG wire is... interesting. What's the amperage of the panel breaker feeding that circuit?

It is interesting. We're beginning to question the quality of the installation. That wire only feeds the heat strips. It was leftover from the prior HVAC system that only had 5kw heat strips I believe; we can't blame the installer for using the wire that was already there. We have 15kw heat strips now. But, that breaker had no power. We traced that wire back to the house panel and discovered it isn't connected at all. It's just wound up in the back of the panel box. So, we learned that despite having 15kw heat strips they aren't all connected. My new HVAC guy is coming back to replace the failed breaker. He's also planning to connect that wire with a new breaker in the panel box. Not sure what size he can use though or how many of the heat strips he can run with the breaker he uses.

 

[3393RP]

It is interesting. We're beginning to question the quality of the installation. That wire only feeds the heat strips. It was leftover from the prior HVAC system that only had 5kw heat strips I believe; we can't blame the installer for using the wire that was already there. We have 15kw heat strips now. But, that breaker had no power. We traced that wire back to the house panel and discovered it isn't connected at all. It's just wound up in the back of the panel box. So, we learned that despite having 15kw heat strips they aren't all connected. My new HVAC guy is coming back to replace the failed breaker. He's also planning to connect that wire with a new breaker in the panel box. Not sure what size he can use though or how many of the heat strips he can run with the breaker he uses.

You can absolutely "blame the installer" for connecting improperly sized conductors to a breaker that is rated at 2.5 times the current capability of the wire. It's time to call an electrician. It's a situation with improper protection of conductors, and the HVAC guy doesn't know anything about sizing circuits and protection. Your safety is involved.

It would also be an opportunity to have the rest of your electrical system checked.

 

[SoonerAviator]

Certainly a unique way of doing it. I guess if the air handler requires 220V for the heat strips, it makes as much sense as anything. I'd just think that the regular circuit breakers would provide the rated protection and leave it at that, rather than having circuit breakers on your circuit breakers. Even a standard fused-disconnect would have been a bit more common.

 

[3393RP]

Certainly a unique way of doing it. I guess if the air handler requires 220V for the heat strips, it makes as much sense as anything. I'd just think that the regular circuit breakers would provide the rated protection and leave it at that, rather than having circuit breakers on your circuit breakers. Even a standard fused-disconnect would have been a bit more common.

The manufacturers put circuit breakers in air handling units for safety and liability purposes. It protects their equipment from dangerous and illegal installations. Those AHUs are in occupied dwellings.

 

[SoonerAviator]

The manufacturers put circuit breakers in air handling units for safety and liability purposes. It protects their equipment from dangerous and illegal installations. Those AHUs are in occupied dwellings.

I just installed a Goodman unit a month ago (myself, not an HVAC company). There were no internal circuit breakers. There are the typical automotive-style 5A fuse on the circuit boards though. I have a dedicated circuit breaker at the house panel and a fused disconnect on the outside unit. My furnace has a simple light switch to turn power on/off to the air handler. Mine is gas-fired rather than heat strips.

I figured the internal circuit breakers are due to 220V being needed in this handler especially with the heat strips.