Harman Pressure Sensor Vacuum Switch, 3-20-6866-AMP


A $15.00 Savings vs the OEM

SKU 3-20-6866-AMP
MPN 3-20-6866
  • After Market Part
  • Try the OEM version of this part
  • Compatible Replacement For Part 3-20-6866
  • Made In The USA
  • Ships FREE with orders over $99
  • 30-Day hassle free return policy
  • Express Shipping available
  • 90 Day Warranty On All Items
  • Learn More...


This part is also known as a "Vacuum Switch." The vacuum switch is the stoves way of knowing it has an airflow through the venting in the proper direction. If the vacuum switch doesn't see a pressure difference it will not remain closed. When it opens the auger is stopped, depriving the stove of fuel and leading to shut down.Replaces part numbers 3-20-9301 & 3-20-3433

Switch is set to .10 WC PF

A 2 blink status light error signifies that the stove’s pressure switch has failed to close the electrical contacts of the switch or that the contacts were closed and an event caused the contacts to open.

The feeder motor has an electrical circuit that runs through a pressure switch. This switch MUST detect a drop in air pressure within the stove to enable the feed motor to have power. It is very rare that the switch itself will fail and should only be considered for replacement after all troubleshooting efforts have been attempted.

The most common solution to get rid of a 2 blink error code is cleaning the stove and venting. Ash obstructions within either the stove or venting will cause back pressure within the stove, thus keeping the switch itself from completing the feed motor circuit. Verify that the stove and venting are clean and clear of obstructions and restart the stove. If the problem persists, verify that the combustion blower is actually powered up and spinning. If the combustion blower isn’t turning on or spinning, no air will be flowing through the stove and the air flow switch will not close.

If you recently performed a cleaning or service (or had a cleaning or service performed by a service technician) and the #2 error presented itself AFTER the service, there is a good chance that something wasn’t put back together properly or something was damaged.


Replacement For Part Number :
  • 3-20-6866

Compatible Models


  • Absolute 63
  • Accentra 52i
  • Accentra 52i TC
  • Accentra Cast Free Standing
  • Accentra Insert
  • Advance
  • Allure 50
  • HF60
  • P35i
  • P35i-C
  • P38
  • P38+
  • P43
  • P43-C
  • P61
  • P61-C
  • P61A
  • P68
  • PC45
  • XXV

Technical Specs

.10 WC PF


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 $99!

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 $99 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.

If you wish to calculate shipping for an item which does not qualify for free shipping, or if you would like the cost to expedite your order, please do the following. Add the item you want to order to your cart and click here to be taken to the cart page where you can enter your country, state / province, and zip code for an estimate.

Shipping Time Estimations

For information on shipping time estimations, see either the Shipping Information & Transit Times on the cart page, or go to our shipping page.

Read More About Our Shipping Information

Customer Reviews

Based on 4 reviews
Fast Shipping

Although I kept the vacuum switch as a spare part, I did install the AMP igniter for my Harman Accentra 52i and it's working fine. I was impressed with the fast shipping to get the stove back on line.


Pressure sensor


Parts came on time and well wrapped happy with the order

Great Service

Finding parts for my Harmon stove is a challenge in Canada, and even when i find a source, they are out of stock and extremely expensive. Thank you Stove Parts 4 Less, for great selection, prompt delivery, and best of all, great prices

Steve ON, Canada


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