Pentair Ultratemp 120 Fan stop during start delay

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Matthewrehm

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Mar 31, 2023
10
Ponte Vedra, FL
I have a 10yr old Ultratemp 120. I have made repairs in the past, but this one has me stumped. The unit powers on without issue, with the pool water temp below the desired temp when I start the unit the fan starts, and the 5min delay starts. During the delay, typically with less than 3min on the countdown the fan will stop. At the end of the countdown the compressor will start and I will start to feel cold air come off the unit. After a short period of time with the compressor on and the fan off I will get an error and it will shut down for frost.

I have been reading throughout this great forum and have so far replaced the Capacitor and the Evaporator Fan Relay. Both replaced and no change to the startup issue.

I have tried giving the fan a push to see if it will get going, but the fan will not start. I have been thinking the fan motor may have an issue, but the fan starts without fail every time I power on the unit. The fan just stops during the delay and will not start again.

I am all for replacing parts and working on this myself, but I am stumped..

Any and all advice is appreciteted!!
 
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I’m guessing you’re not getting information on the error? I’m no expert by any means but I wonder if you have a high or low pressure condition ( low Freon). This is indicated by it starting up normally, then stopping after a bit.

generally they will behave like this because there is a pressure switch that kicks in to protect the compressor but it has to run for a bit to detect it. This gets the unit into a cycle Of starting and stopping.

edit: sorry for the typos… bumpy flight.
 
Ok, this could 100% be the case and I am far far form an expert.. :) If I wanted to explore to see if I have a high or low pressure condition what would I do next? It sounds like it is past an internet fix, so if I asked a HVAC tech out what would I ask them to look for?

Just wondering if that is still the case when the compressor seams to be working without issue but the fan stops? I think the system would work if the fan would just keep going. Does that still fit with what is going on?


Do I still have any homeowner options to try or is it time to call in the pros?
 
You need an HVAC tech with an EPA certification and the proper gauge setup to check the refrigerant pressures. Diagnosing an HP is no different then an AC system.
 
As @ajw22 says, it’s time to call in an HVAC tech. At that age, it could be anything, but there’s a good chance it’s a charge issue. If it is, you’ll be spinning your wheels, if it’s not, there’s still a good chance it’s a bit low which topping it off will help it work just a tad bit better, and giving it a little bit of help lasting. Even if it isn’t leaking, there’s always loss after a while.
 
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Matthewrehm said:
After a short period of time with the compressor on and the fan off I will get an error and it will shut down for frost.
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The unit can't run correctly without the fan.

You need to figure out why the fan is stopping.

Check the voltage and current to the fan during initial startup and when it shuts down.

If the current exceeds the motor label, then that points to a bad motor if the voltage is good.

If the voltage is dropping out, that points to a control issue.

Is the fan motor getting hot?
 
JamesW said:
The unit can't run correctly without the fan.

You need to figure out why the fan is stopping.

Check the voltage and current to the fan during initial startup and when it shuts down.

If the current exceeds the motor label, then that points to a bad motor if the voltage is good.

If the voltage is dropping out, that points to a control issue.

Is the fan motor getting hot?
Click to expand...
No, not hot. It does not run long enough to get hot. It starts every time and then stops.. I will start looking for someone to check the refrigerant pressures and see if that is an issue.. I agree after this much time it is a good idea regardless. It is just very puzzling to me that it never fails to start and it always stops.. It feel like a control issue, that is why I started with replacing the fan relay switch, but no idea what would tell it to stop.. Maybe a part I can replace.. :) I appreciate all the help and will keep working on it..
 
A refrigerant pressure problem should not cause the fan to stop running, especially since the compressor is turning on.

I would check the voltage, current and power factor of the electricity going to the fan motor to see if the motor is the problem or if the controller is turning off power for some reason.

Are you sure that you replaced the capacitor with the correct one and did you wire it correctly?

Was it a dual capacitor?

Does the motor spin easily?

Did you actually feel the motor to see if it is getting hot?
 
JamesW said:
A refrigerant pressure problem should not cause the fan to stop running, especially since the compressor is turning on.

I would check the voltage, current and power factor of the electricity going to the fan motor to see if the motor is the problem or if the controller is turning off power for some reason.

Are you sure that you replaced the capacitor with the correct one and did you wire it correctly?

Was it a dual capacitor?

Does the motor spin easily?

Did you actually feel the motor to see if it is getting hot?
Click to expand...
I will work to see if I can narrow down the the voltage question. Great point, is the fan getting electricity and not spinning or is it being told to turn off?

If it was being told to turn off, any thoughts on what could cause this? This was my first thought and why I tried replacing the Evaporator Fan Relay, then went on to the capacitor.

I replaced the capacitor with - HUAREW 80+7.5 uF ±6% 80/7.5 MFD 370/440 VAC CBB65 Dual Run Start Round Capacitor for Condenser Straight Cool or Heat Pump Air Conditioner or AC Motor and Fan Starting: Amazon.com: Industrial & Scientific
Thank you to another post in this forum I found the link..:)
I do believe I wired it correctly, copied how it was before (Pink to C/Brown is Fan/Purple is compressor to HERM)..

The fan does make a good bit of noise when it spins, it is far from new, but it starts up without hesitation. Sounds like an old AC unit.

I have been shutting the system down when the fan stops, but will let it run for a bit and see if the fan motor feels hot.

Thank you again for taking the time to help!
 
You replace this capacitor and relay?

Use your voltmeter and check for voltage starting on the board at OUTPUTS D. If the board is dropping voltage to the fan relay then you have a control problem.

IMG_0970.jpeg
 

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ajw22 said:
You replace this capacitor and relay?

Use your voltmeter and check for voltage starting on the board at OUTPUTS D. If the board is dropping voltage to the fan relay then you have a control problem.

View attachment 479850
Click to expand...
I do not know if it makes a difference, but this diagram says the "Single Phase – 50Hz/60Hz" also and is how I believe mine is wired.. It is what I have been using so I hope it is correct..:)
14539959_pdf.jpg
 
Ok, it took some time to get someone out to look at the heat pump, but we found the issue today. I did not feel comfortable checking all the voltage correctly so I got an expert.
The result is a bad fan motor. It is drawing 5amp and should be much lower. From my above description it took 3-4min of the fan running to overheat and stop. The tech says it sound like a bad barring.
Now I am in a position of needing to find the motor and the tech will come back out and install it for me. The Pentair part number looks to be 473785 and a search on eBay for that part gets me a "US Motor" part and $300-$400+ for the part depending on who is selling.
Is this the cost I should expect for the part or does anyone have a better recommendation to get the motor?
Thank you again for all the assistance!!
 
See if they can match the motor with an equivalent.

Contact

Moline Electric Motor & Machine Inc. is a family-owned, full service, electro-mechanical repair facility that provides pump and electric motor repair throughout the Jacksonville and Northeast Florida area.
molineelectric.com

About Us

Moline Electric Motor & Machine Inc. is a family-owned, full service, electro-mechanical repair facility that provides pump and electric motor repair.
molineelectric.com

Moline Electric
1420-3 Mayport Rd.
Atlantic Beach, Florida 32233
Phone: (904) 247-3376

www.parts4heating.com

Parts4Heating.com: Pentair 473785 Fan Motor w/ Acorn Nut Kit

Parts4Heating.com: Pentair 473785 Fan Motor w/ Acorn Nut Kit
www.parts4heating.com

1681936370607.png
1681936466916.png
 
JamesW said:
See if they can match the motor with an equivalent.

Contact

Moline Electric Motor & Machine Inc. is a family-owned, full service, electro-mechanical repair facility that provides pump and electric motor repair throughout the Jacksonville and Northeast Florida area.
molineelectric.com

About Us

Moline Electric Motor & Machine Inc. is a family-owned, full service, electro-mechanical repair facility that provides pump and electric motor repair.
molineelectric.com

Moline Electric
1420-3 Mayport Rd.
Atlantic Beach, Florida 32233
Phone: (904) 247-3376

www.parts4heating.com

Parts4Heating.com: Pentair 473785 Fan Motor w/ Acorn Nut Kit

Parts4Heating.com: Pentair 473785 Fan Motor w/ Acorn Nut Kit
www.parts4heating.com

View attachment 484232
View attachment 484233
Click to expand...
Thank you for the response!!!! Local!! So over $400 is what I should expect for this fan motor? Guessing it is specific to the Pool Heat pump? Sounds like most home AC heat pump fan motors must cost a lot less.. I will get it ordered ASAP.. We called the supplier my HVAC tech uses and they could not find the part based on that model number..
 

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