Harman Room Temperature Sensor, 3-20-00906-OEM

SKU 3-20-00906
MPN 3-20-00906
In Stock
Notify Me When Available

Frequently Bought Together


This room-temperature sensor is required by all Harman pellet stoves and inserts to use the "Room Temp" or "Automatic" mode setting on older units without a touchscreen.

 A 4 BLINK error code at startup is triggered when the controller doesn't detect this probe. This error usually means the probe is damaged but the error can also happen if the probe has become unplugged.

If your probe is missing or damaged the unit can still be used by selecting the"Stove Temp" or "Constant Burn" setting but you will lose the automatic temperature control.

When this probe is attached and functioning and, if the probe is placed properly, your Harman stove or insert should be able to regulate the desired temperature in the room within 1°F of the setpoint on the dial.

There is a 14-foot extension wire available for this probe if you need to extend the length for better placement of the probe, Part # 3-20-674101

Replacement For Part Number:
  • 3-20-00906

Click To See Compatible Models
UPC: 652174686964

Compatible Models


  • Accentra 52i
  • Accentra Cast Free Standing
  • Accentra Insert
  • Advance
  • Invincible Insert
  • Invincible RS
  • P35i
  • P35i-C
  • P38
  • P38+ (Post: 008190059)
  • P43
  • P43-C
  • P61
  • P61-C
  • P61A
  • P68
  • P68-C
  • PB105
  • PC45
  • PF100
  • PF120
  • Super Magnum Stoker
  • XXV

    Legacy Stoves

  • Super Magnum Stoker

Technical Specs

Length of wire 60 inches
Standard Type 18-2 braided wire
Wire Connections ¼" Female Spade


Assembly Instructions For Harman Room Temperature Sensor, 3-20-00906-OEM

Installing a new probe is as easy as unplugging the bad one and plugging in the new one. This probe is designed to be plugged into the jack mount locate don the back of freestanding stoves. Insert units will connect to the blue pigtail wires which are connected to the controller.


The probe is designed to measure the air temperature at the end of the wire probe. In "Room Temp"/ "Auto" mode, realtime measurements of the room air temperature allow the unit to oscillate between heating up as demanded or idling down as the set point is achieved. If you have the wire near a heat source, such as too close to the stove or venting or in the direct sunlight, your stove will cool down thinking that the room is warmer than it actually is. Likewise, if the end of this probe is near a cold surface, such as a cement floor or drafty doorway, the stove will product more heat than necessary. An ideal spot for the probe is either directly under the unit near the distribution air fan (measuring incoming room air) or somewhere behind the stove, roughly 18" above the floor, out of direct sunlight and preferably not on a cold exterior wall. It's not uncommon to have to play with the placement of this wire to get the stove calibrated properly as there is no way to manually calibrate the signal of the probe.


Unfortunately, sometimes products do not work like they are supposed to. We offer a 90 day warranty on manufacturer defects. Some manufacturers make this a very simple and easy process unfortunately others do not. Items must be used in accordance with the manufacturers guidelines to qualify for warranty replacement. Please be advised that warranty claims for these parts may take up to 4 weeks for processing, and customers must cover shipping.

Shipping Info

This Item Qualifies For Free Shipping With Orders Over $199!

When Will My Order Ship

All orders are typically processed within 24 hours of receiving payment and are shipped from us same day if placed before our shipping cutoff time (Monday - Friday: 1PM, Saturday: 10AM, Sunday: No Shipping), orders placed after our cutoff time are shipped the next morning.

How Does Free Shipping Work?

Most orders over $199 qualify for free shipping! Orders which ship for free are shipped with either USPS or UPS based on our discretion. If you are using a PO box, free shipping orders will always go USPS.

Is Expedited Shipping Available?

We offer both overnight and two day air shipping services for all orders placed within the Continental United States. For information on shipping cut-off times, go to our shipping page.

Do You Ship To Canada?

We ship to Canada! We estimate USPS to take 4-10 days once receiving your package from us. We do not offer expedited shipping of any kind to Canada. Please allow an extra 2-5 days for all shipments to Canada. Free shipping is not available to Canada.

Do You Ship To Alaska Or Hawii?

We ship to both Alaska and Hawaii! We do not offer next day or two day shipping to Alaska or Hawaii. Free shipping is not available to Alaska or Hawaii.

Do You Ship Outside The US Or Canada?

Unfortunately, at this time we do not offer international shipping other than to Canada.

Shipping Time Estimations

For information on shipping time estimations, see the Shipping Information & Transit Times on the shipping page.

Read More About Our Shipping Information

Customer Reviews

Based on 12 reviews
Room Temp Sensor

Product came in exactly what I ordered in OEM packaging. Shipping was fast. Thank you for providing parts for our home heating appliances.

Brian V.

Harman Room Temperature Sensor, 3-20-00906-OEM

Jeannine S.
Room Temp

The part is working as expected. The house is nice and warm now.

David M.
Room temperature sensor

Came exactly as ordered. Very pleased. Also guide for install if needed

Willard R.

very well happy