Accentra 52i-TC combustion blower RPM error

[Boostgauge]

Hello, this is my first post and it’s a long one. My wife and I had a Accentra 52i-TC professionally installed late October 2025. It is my first pellet stove after suffering through a 1986 Vermont Castings Defiant Encore wood stove that couldn’t burn more than 4 hours. I’m not entirely in love with this new pellet stove but I’ll cover that later.

The current problem with the pellet stove is that it will have a combustion fan RPM error intermittently. It started 5 days ago when I came downstairs in the morning to find the stove shutting down even though the room wasn’t up to temp. The error was displayed and there was no RPM reading BUT the fan was still operating. Air was being forced through the throat and the fire was not smoldering. I ate breakfast and came back to find it operating without issue, RPM reading was back.

The stove ran fine for 24 hours. I came home the following night and found that the stove had not run since the morning cool down cycle. The screen was showing the combustion fan RPM error and it would not fire. The stove was due for a complete cleaning right down to the day so I performed that full cleaning and rebooted the stove, but it still did not run.

My dealer came out the next day and did a few things to it, although I don’t know exactly what. The stove did not work that night or the next day.

The day after that, the dealer returned and said that Harman told them to replace the control board, the combustion blower and the wiring harness. The stove ran fine for more than 24 hours. Last night after the fire was out due to the schedule I went to scrape the throat and the screen displayed the combustion fan RPM error once more! I did not have my phone on me so I went to get it to take a picture for the dealer but by the time I got back to the stove the error had cleared. When the error was displayed there was still air being forced through the throat.

Today the stove fired fine on its own per the schedule and has stayed running. This problem is of course happening during one of the coldest stretches of weather we’ve experienced in a while.

I’d really like to know how the fan RPM sensor works. I’m an automotive technician with 20 years experience and I’m familiar with all types of sensors and their intermittent failures. I’d rather not have to put effort into fixing it myself since it’s under warranty but if they prove incapable of fixing it I may have to step in.

The stove is plugged into a Tripp-Lite APS750 that has a 100Ah AGM deep cycle battery for power backup and voltage regulation. We haven’t yet experienced a power failure (remarkable for our location) but the APS750 is supposed to provide stable voltage regardless of whether it’s brownouts or complete power failure.

Has anyone been here before? I am concerned I have a lemon stove on my hands. And this is not even considering the noises and vibrations this thing makes during “normal operation.” I also need an outside air kit next season. Thanks for your time and consideration.

- Mike

 

[Washed-Up]

Sounds like the combustion blower maybe in need of a cleaning, you’ll have to pull it out and check the fan blades, it’s that or you have a blockage in your air intake

 

[Whitenuckler]

Hello, this is my first post and it’s a long one. My wife and I had a Accentra 52i-TC professionally installed late October 2025. It is my first pellet stove after suffering through a 1986 Vermont Castings Defiant Encore wood stove that couldn’t burn more than 4 hours. I’m not entirely in love with this new pellet stove but I’ll cover that later.

The current problem with the pellet stove is that it will have a combustion fan RPM error intermittently. It started 5 days ago when I came downstairs in the morning to find the stove shutting down even though the room wasn’t up to temp. The error was displayed and there was no RPM reading BUT the fan was still operating. Air was being forced through the throat and the fire was not smoldering. I ate breakfast and came back to find it operating without issue, RPM reading was back.

The stove ran fine for 24 hours. I came home the following night and found that the stove had not run since the morning cool down cycle. The screen was showing the combustion fan RPM error and it would not fire. The stove was due for a complete cleaning right down to the day so I performed that full cleaning and rebooted the stove, but it still did not run.

My dealer came out the next day and did a few things to it, although I don’t know exactly what. The stove did not work that night or the next day.

The day after that, the dealer returned and said that Harman told them to replace the control board, the combustion blower and the wiring harness. The stove ran fine for more than 24 hours. Last night after the fire was out due to the schedule I went to scrape the throat and the screen displayed the combustion fan RPM error once more! I did not have my phone on me so I went to get it to take a picture for the dealer but by the time I got back to the stove the error had cleared. When the error was displayed there was still air being forced through the throat.

Today the stove fired fine on its own per the schedule and has stayed running. This problem is of course happening during one of the coldest stretches of weather we’ve experienced in a while.

I’d really like to know how the fan RPM sensor works. I’m an automotive technician with 20 years experience and I’m familiar with all types of sensors and their intermittent failures. I’d rather not have to put effort into fixing it myself since it’s under warranty but if they prove incapable of fixing it I may have to step in.

The stove is plugged into a Tripp-Lite APS750 that has a 100Ah AGM deep cycle battery for power backup and voltage regulation. We haven’t yet experienced a power failure (remarkable for our location) but the APS750 is supposed to provide stable voltage regardless of whether it’s brownouts or complete power failure.

Has anyone been here before? I am concerned I have a lemon stove on my hands. And this is not even considering the noises and vibrations this thing makes during “normal operation.” I also need an outside air kit next season. Thanks for your time and consideration.

- Mike

Harman Combustion Blower Exhaust Motor with Capacitor: 1-00-02275

This replacement combustion blower motor is used in ALL Harman pellet stoves and inserts that have the Easy-Touch touchscreen controller mounted on the hopper lid. The motor comes with a new start/run inline capacitor. Check out all of the latest Harman part updates, same-day shipping!

pellet-stove-parts-4less.com

There seems to be some extra wires for the motor. There could be a speed sensing probe in there.

Manual:

https://forgedistribution.com/wp-content/uploads/2016/12/Accentra52i-TC-Owners-Manual.pdf

 

[Ssyko]

There seems to be some extra wires for the motor. There could be a speed sensing probe in there.

Yes more than likely they are PWM motor’s, sensors for speed and torque. This seams to be the culprit of rpm issues.
PWM explained

 

[Whitenuckler]

The day after that, the dealer returned and said that Harman told them to replace the control board, the combustion blower and the wiring harness. The stove ran fine for more than 24 hours

That should fix 99% of any possible problems. The only thing left would be something binding up the fan blade so it can't go as fast as the control board tells it too.

 

[Whitenuckler]

The stove is plugged into a Tripp-Lite APS750 that has a 100Ah AGM deep cycle battery for power backup and voltage regulation

Note that this UPS is not a true sine wave output, so depending on your board and dipp switches, it may do a pulse shutdown on a power outage, not stay running normally. Not related to your issue as you are in bypass mode normally and it provides filtering.

 

[Boostgauge]

The final fix for this issue, according to the dealer, was a bad pin in a harness deeper in the stove. I was not home when they fixed it but I know they were here for several hours and said they found it after replacing a second board inside the stove and the no RPM problem still happened. They must have powered up the stove/exhaust fan and then poked and prodded the wiring. He said he found when he pushed on the wire at the connector he would get RPM reading and when he let go, the reading would go to zero immediately. They did not tell me exactly where the problem was and I was dealing with a minor family emergency so I forgot to ask. I also did not get a chance to take it apart and see exactly how the fan and sensor operate. When it’s out of warranty and I have to slide it out, I intend to figure out exactly how it works.

The only upside to being without the stove during a remarkable cold snap is that the new exhaust fan and blade assembly they installed have made the stove significantly quieter on start up, with much less humming/vibration.

 

[Whitenuckler]

The final fix for this issue, according to the dealer, was a bad pin in a harness deeper in the stove. I was not home when they fixed it but I know they were here for several hours and said they found it after replacing a second board inside the stove and the no RPM problem still happened. They must have powered up the stove/exhaust fan and then poked and prodded the wiring. He said he found when he pushed on the wire at the connector he would get RPM reading and when he let go, the reading would go to zero immediately. They did not tell me exactly where the problem was and I was dealing with a minor family emergency so I forgot to ask. I also did not get a chance to take it apart and see exactly how the fan and sensor operate. When it’s out of warranty and I have to slide it out, I intend to figure out exactly how it works.

The only upside to being without the stove during a remarkable cold snap is that the new exhaust fan and blade assembly they installed have made the stove significantly quieter on start up, with much less humming/vibration.

That makes sense. The wires go into a plug/connector and the wire is crimped or soldered onto a pin. Hard to find and troubleshoot unless you try everything and it still does not work. When you can make it come and go by touching something then you are half way there to fixing it. You are fortunate to have some good help you can call out.

 

[Boostgauge]

That makes sense. The wires go into a plug/connector and the wire is crimped or soldered onto a pin. Hard to find and troubleshoot unless you try everything and it still does not work. When you can make it come and go by touching something then you are half way there to fixing it. You are fortunate to have some good help you can call out.

I am thankful they figured it out. It took longer than I wanted but in the end it does seem to be fixed. I regard the old wiring poke n’ prod as a primary or secondary diagnostic step, especially prior to replacing components that cost someone money (this time it was Harman spending and not me.) Hopefully they learned something here and can save someone the headache that I went through.

 

[Whitenuckler]

I am thankful they figured it out. It took longer than I wanted but in the end it does seem to be fixed. I regard the old wiring poke n’ prod as a primary or secondary diagnostic step, especially prior to replacing components that cost someone money (this time it was Harman spending and not me.) Hopefully they learned something here and can save someone the headache that I went through.

Very few people have problems with wiring harnesses, and although we sometimes mention "check the wiring", unless it obvious like a grounded wire or loose stab connection, it's hard to find. Most people don't measure each wiring path from the device to the board and wiggle. This goes to show that some dealers live up to the Harman warranty terms, and supply parts and labor, and have the knowledge of electrical. My dealer here did an excellent job on the install, as he is a wood stove guy. I'm the one that got mine going at the beginning, and I would never expect him to come and repair the stove. I would try and get warranty parts, but mine is now over a year old so probably the the warranty is up. I have had zero problems besides operational/cleaning issues. They were in touch with "Harman" I bet so even Harman advised them to change parts to solve it. Glad they found the issue while under warranty.