Harman p61 won't shut down after cool off.

[Spaz]

Just started up my P61 for the season. It's a manual with a new board, worked fine until I shut it down for the seaon. It started fine ran fine on 1 for 3 hours. I shut it off as usual and it did the cool down, but failed to turn off the fan besides the fact that the exhaust was room temp 76f at the ESP. After an hour I unplugged it and plugged it back in, and it the started up with the fan and then completey shut down. I read it should shut off at 90f. I also tried switching from auto to manual , nothing changed.

 

[ARC]

Clean ESP? CheckESP leads attached at board. New board, are dips set for correct color esp? If you have a good multi meter test ESP for OHM's. No error codes???

Understanding the Harman P61 ESP System

• Function:The ESP system uses the Exhaust Sensing Probe (ESP) to constantly monitor the exhaust temperature and adjust the stove's heat output to maintain your desired room temperature more precisely.
  • DIP Switch 5: This switch is crucial for identifying the ESP probe wire color.
    • 0 (OFF): Use for a black ESP wire.
    • 1 (ON): Use for a red ESP wire.
• 
  For a Harman P61, the Exhaust Sensing Probe (ESP) should read around 550,000 to 650,000 ohms (550k-650kΩ) when cold, and its resistance should decrease as it heats up. To test this, set a multimeter to measure resistance in the megaohm or kiloohm range and place the leads on the probe wires. A reading significantly outside this range, or one that doesn't change with temperature, suggests a faulty probe

For a Harman P61, the Exhaust Sensing Probe (ESP) should read around 550,000 to 650,000 ohms (550k-650kΩ) when cold, and its resistance should decrease as it heats up. To test this, set a multimeter to measure resistance in the megaohm or kiloohm range and place the leads on the probe wires. A reading significantly outside this range, or one that doesn't change with temperature, suggests a faulty probe.



Testing the ESP Probe

1. Locate the probe: Find the probe, which is usually a black wire for the ESP probe in the exhaust.
2. Disconnect: Unplug the probe from the stove's circuit board.
3. Set your multimeter: Switch the multimeter to an appropriate range for high resistance, such as 200kΩ or 2MΩ.
4. Take a reading: Place the multimeter leads on the two wires coming from the probe.
5. Interpret the reading:
   • Normal: A reading between 550,000 and 650,000 ohms indicates a functional probe.
   • Faulty: Readings significantly outside this range or that do not change when the probe is warmed (e.g., by breathing on it) point to a failing probe.

Common Issues with a Bad ESP Probe

• Incorrect Room Temperature:If the stove is not maintaining the set room temperature, the ESP probe may be faulty.
• Stove Malfunctions:A faulty ESP probe can trigger error codes or cause the stove to shut down unexpectedly.
• Poor Performance:The stove may not be heating efficiently or may be over- or under-heating.

 

[Spaz]

Worked okay with the new board for 2 months before I shut it down. And no codes. And thanks for the technical info . 👍

 

[ARC]

Worked okay with the new board for 2 months before I shut it down

I would make sure it is clean, OHM test it if you can. Buy a replacement even if it turns out the one you have is not bad, good to have a second one on hand. $20-40 depending on were you buy it or $139 for OEM.

 

[Whitenuckler]

Run in stove mode at a setting of feed of 2 and stove pot at near min. You will soon know if the probe is good.
I am suspecting the new board may have a bad connection where the probe lands.

 

[Spaz]

It turns the fan on, on start up and shuts the stove down on shut down just won't turn off the fan. Unless it takes more then an hour. I've owned it a year and this is a first. I'm running it again tonight and see what happens in the morning.

 

[Whitenuckler]

It turns the fan on, on start up and shuts the stove down on shut down just won't turn off the fan. Unless it takes more then an hour. I've owned it a year and this is a first. I'm running it again tonight and see what happens in the morning.

Just to double check, when you say fan, it is the distribution blower we are talking about? So the stove starts up fine, and runs good, then you shut it off, but the room dist fan keeps running? If it runs properly in stove mode it is not the probe. Sounds like a control board issue. If it is under warranty I'd call the supplier.
If it is the combustion blower staying on, same issue really. In fact if the dist blower shuts off, but not the comb blower (ever) then looks like a bad board. You might not get a valid fault code for these types of problems. Make sure you have good surge protection.

 

[Washed-Up]

Was it plugged into a surge protector?

 

[bogieb]

I always check the free stuff first, especially if it worked fine, then just decided to be weird.

Check that both doors are closed correctly (open them and close them). Also check the hopper lid - open it, make sure there are no tiny pieces of pellet in the way (especially if you have a rod that senses the door closure - they like to hide over there), then close it again.

 

[Spaz]

I did another test this morning, and it took an hour 3 minutes and it shut down. Missed it by minutes. 😲

 

[Whitenuckler]

I did another test this morning, and it took an hour 3 minutes and it shut down. Missed it by minutes. 😲

If you started to time it after it was switched to off, and it was running for a long time, then the distribution blower would shut off after maybe 20 minutes? and then the combustion blower would take MUCH longer. If it all is shutting down after an hour then that sounds good. Maybe the ESP probe is dirty. You can open up your combustion motor hatch door and look inside. You can use a soft bottle cleaning brush with a long handle to GENTLY clean in there (just did it yesterday). How does it run in stove mode?
Also - do you have OAK? If you are drawing in warm room air for combustion, it is going to take a lot longer to cool down.

 

[Spaz]

The distribution fan turned of after 15 minutes. The combustion fan was just over a hour. I'm sucking air from inside. I run it strictly in stove mode. It's a manual start, so I don't have to worry about it turning off and me having to restart it again and again. I have a Quadrafire I use for back up and it has a remote control and thermostat. I'm using until it gets cold enough the run the Harman full time. This was the fall test/start up. Thanks everyone for the advice.