Harman Accentra FS stove not working

[Dave_NV]

I have a 10 yr old Harman Accentra FS stove that is not working. In test mode or any mode, the feed motor light comes on but doesn't turn and the combustion motor light does not come on or turn. The distribution blower works. There aren't any warning or flashing lights on. Here are the things I've tried with no change in condition:

• Cleaned the stove and the vent pipe, checked for blockages, there are none. (It was also professionally cleaned end of last season since I was having creosote problems. I also replaced the door gasket and hopper lid gasket last season.)
  
• Removed the auger looking for foreign objects, found none, cleaned and reinstalled it.
• Removed and bench tested feed motor, works fine.
• Jumped the differential switch, found that feed motor then works.
• Blew air through the differential switch hose to clean out any dust. I'm unable to access the other end of the hose to inspect since it goes into the air intake box and is difficult to reach but air blows through the hose.
  
• Replaced the differential switch.
• Replaced the combustion motor and fan.

Any help or suggestions would be appreciated, it's hard to get service techs to return calls here.

 

[RKS130]

I had a similar issue with my Accentra FS last year, although I had a five blink error code, indicating lack of ignition.

I too did what I thought was a complete cleaning to try and remedy the situation, with no result. I posted my problem here and the problem was solved by Eric Kinsman. He suggested that I back off the screws holding the ignitor by two turns and then tap the ignitor cradle to clean it. I then retightened the retaining screws and fired her up.

Bingo! Worked like a charm and the stove has run beautifully ever since. I have also followed his advice to add this cleaning of the ignitor after each ton faithfully.

Might be worth a try for you.

 

[Dave_NV]

Thanks for your reply. I'm not getting any error code, but I tried doing as you suggest and unfortunately no change. Something is causing the pressure switch to stay open, could it be the control board? At $220, I don't want to just blindly replace it. Any other suggestions, anyone?

 

[alternativeheat]

Does this stove have a hopper switch ? The symptoms are much like an open hopper on stoves with a hopper switch.

 

[RKS130]

There is a hopper interlock . . . worth taking a look at.

 

[alternativeheat]

Inspect gaskets closely. If the vacuum switch was replaced, the hose flows air and isn't cracked or leaking and the stove doesn't run, but jumping it out did let the stove try to run. Then obviously you are losing vacuum. Or the board thinks so. Common reasons would be lack of vacuum for real, like cracked or missing or non tight fitting gaskets ( we have had some failed stoves with loose door gaskets lately here !). Another switch or safety is at fault , like the hopper door switch. Etc.

 

[SidecarFlip]

Cheap date is fluffing the door gaskets with a pet hair brush or a stiff toothbrush. It buys time and eliminates that issue. If it is the gaskets, you will have to replace at some point.

 

[Dave_NV]

Thanks for all the suggestions. I'm new to all this. But I don't think this stove (built in 2002) has a hopper switch, no mention in the owner's manual or wiring diagram. I also don't think it's losing vacuum since I had replaced gaskets last year. The problem seems to be that the combustion blower isn't working at all so there's no vacuum to close the vacuum switch and operate the feeder motor and igniter. Since I replaced the blower, the problem has to be upstream which could only be at the control box. Does that sound right? If it is, how hard is it to replace the circuit board, should I tackle that or try to get a service tech?

 

[MSmith66]

It is possible that the hose on the air switch is plugged or if there is a hopper (orange button) air switch in hopper, that hose maybe plugged. Also check ESP probe.

 

[Bioburner]

Have you tested the exhaust fan by using a separate pigtail cord to rule out a bad motor before we jump to having to get a new $200 board?

 

[F4jock]

Thanks for all the suggestions. I'm new to all this. But I don't think this stove (built in 2002) has a hopper switch, no mention in the owner's manual or wiring diagram. I also don't think it's losing vacuum since I had replaced gaskets last year. The problem seems to be that the combustion blower isn't working at all so there's no vacuum to close the vacuum switch and operate the feeder motor and igniter. Since I replaced the blower, the problem has to be upstream which could only be at the control box. Does that sound right? If it is, how hard is it to replace the circuit board, should I tackle that or try to get a service tech?

Yeah you're probably right. If you can get the board checked out do it.

 

[Dave_NV]

Have you tested the exhaust fan by using a separate pigtail cord to rule out a bad motor before we jump to having to get a new $200 board?

The combustion motor is new, but just to be sure it's working I tested it as you suggest and it works fine. So, there seems to be agreement that the circuit board is the problem. How hard is it to replace, can I do that myself?

 

[Bioburner]

P series is a piece of cake. Two screws and two spades for the room temp probe, simple duplex connector for the ESP and a large connector for the rest. Trial and error for how the board removes flips out from the stove .

 

[3650]

Did the chain come off the auger? Ever clean the fines box out?

 

[Bioburner]

Did the chain come off the auger? Ever clean the fines box out?

He already removed the auger and tested motor.

 

[Dave_NV]

To close this thread out, I installed a new circuit board, which was pretty simple, even for someone inexperienced at it. I didn't put the #5 dipswitch off for my black ESP at first and things didn't work right, but once I corrected that everything works fine and I'm back in business, just in time for a storm on Monday. Thanks again for the responses.

 

[F4jock]

To close this thread out, I installed a new circuit board, which was pretty simple, even for someone inexperienced at it. I didn't put the #5 dipswitch off for my black ESP at first and things didn't work right, but once I corrected that everything works fine and I'm back in business, just in time for a storm on Monday. Thanks again for the responses.

Yep. Congrats and enjoy!