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Tjernlund

Tjernlund PS1503P Plug-in Air Pressure Activation Switch for Duct Fans in Central Heating and Air Conditioning Systems

  • Based on 200 reviews
Condition: New
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Availability: Only 3 left in stock, order soon!
Fulfilled by Amazon
Arrives Wednesday, Sep 2
Order within 15 hours and 53 minutes
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Features

  • Air pressure activation switch automatically turns on and off any device, but in particular it turns duct fans on and off based on the furnace and/or air conditioner blower coming on.
  • Works with any brand duct fan, including Tjernlund Duct Booster Fans.
  • Choose either simple black-to-black, white-to-white wiring (PS1503) or plug-in version (PS1503P).
  • Fool-Proof Tech: simple bladder fills and allows power to flow to the fan, so no errors from over engineered circuit boards.
  • Manufactured in the USA and backed by a 81-year-old family business.

Description

The Tjernlund Duct Airstat senses positive pressure in a forced air heating and/or cooling system. The single pole, single throw, snap-acting switch is activated by a diaphragm with integral pressure probe inserted directly into the duct or plenum. The Duct Airstat can be used to initiate such auxiliary devices as: Duct Boosters, Electronic Air Cleaners, Electrical Duct Heaters, and Humidifiers. The electrical contacts of the switch are closed upon sensing positive air pressure generated by the blower.

Operation Mode: Automatically,Off


Current Rating: 2 A


Operating Voltage: 120 volts


Contact Type: Normally Open


Connector Type: Plug In


Brand: Tjernlund


Switch Type: Flow Switch, Pressure Switch


Terminal: Plug in


Material: Copper, Brass, Silver


Item dimensions L x W x H: 6.81 x 6.38 x 6.34 inches


Operation Mode: Automatically,Off


Current Rating: 2 A


Operating Voltage: 120 volts


Contact Type: Normally Open


Connector Type: Plug In


Switch Type: Flow Switch, Pressure Switch


Terminal: Plug in


Circuit Type: 1-way


Mounting Type: Snap In Mount


Actuator Type: Push Button


Number of Positions: 1


Control Method: Touch


Connectivity Protocol: X-10


Wattage: 5 watts


Control Type: Automatic


Compatible Devices: Duct Fans, Duct Boosters, Air Cleaners, Duct Heaters, Humidifiers


Color: black


Item Dimensions: 6.81 x 6.38 x 6.34 inches


Unit Count: 1 Count


Number of Items: 1


Material Type: Copper, Brass, Silver


Contact Material: Copper Or Brass Or Silver


International Protection Rating: IP00


Brand Name: Tjernlund


Model: B07W7LTY35


Global Trade Identification Number: 32


Manufacturer: Tjernlund


UPC: 080956961532


Included Components: Tjernlund PS1503P Plug-in Air Pressure Activation Switch


Item Weight: 0.27 g


Part Number: PS1503P


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Sep 2

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • Easy to install, solid and does exactly what I needed.
I needed something that would allow my HVAC UV duct light to turn on and off when the furnace/AC fan kicked on. This unit fit the bill perfectly. I was hesitant for a very long time but the UV Light was on constantly whereas the furnace/AC was only running about 20% of the time so I was just shortening the lifespan of the UV Light. It installed within minutes, looks good and works like a champ. Now when the unit detects air pressure in the vent it activates the outlet which the light is plugged in and now the light goes on and off as needed, saving both electricity and life of the UV Light. HIGHLY RECOMMENDED !!!!! ... show more
Reviewed in the United States on September 2, 2023 by Purchaser
    • Works great
Works very well to turn on and off booster fans and other accessories. I am currently using it to switch on a whole house HVAC oil diffuser system and it’s doing a great job.
Reviewed in the United States on March 19, 2026 by William H
    • Works...read review.
I got this to power a couple of boster fans we had added to our HVAC system. I installed according to instructions, even used a level. It worked great for a couple of weeks then started to have issues like it was surging or rapidly switching on and off. I pulled the switch to make sure it was clean and not blocked, same issue. Pulled it again and tipped it about 10 degrees back and now its working as it should. I will update in a month or so. ... show more
Reviewed in the United States on November 21, 2025 by Patrick
    • Pressure Switch Works as Advertised
I bought this to activate UV lights in my home return air duct when the furnace-a/c comes on. To make the job go faster I bought the plug-in model so I wouldn't have to spend time hard wiring it to the UV light setup. The pressure switch is a bit pricey, but worth the money if you want something that will work. It was easy to install and only required drilling one half-inch hole in the discharge duct and setting 4 self-tapping screws. Even if you are sheet-metal challenged this switch is easy to install. There are some position restrictions for mounting it so make sure you have the proper access to your selected duct before ordering. It is sensitive and activates before my furnace fan comes up to full speed. Switch is non adjustable normally off (closes with air flow). ... show more
Reviewed in the United States on January 22, 2021 by Craig W
    • A easy solution to power fan
Works like it should. Easy to install. Purchased with the Tjernlund DB-2 Duct Booster, Increases Heating and Cooling Power, 275 CFM fan. A few improvements to the fan because of the noise it makes. (still working this a bit). This Air Pressure switch made the job very easy. I would suggest positioning the switch in a strong air flow position (vertical) and then position the fan motor where needed and attach an appliance cord to the fan junction the length needed to reach the switch. I foresee the switch lasting far longer than the fan motor. Installed in 10 minutes. ... show more
Reviewed in the United States on December 11, 2022 by my dog's best friend
    • Dont purchase - unreliable - 2nd unit and failing in the same way - stuck in the on position.
Review Image by Jeffrey Gathe
Works great - took 15 min to mount/install in my ac closet. Using it to drive my whole house scent machine. No issues so far - instructions are so-so. No noise during switch activation. A bit expensive but worth it for my need. Revised: Well, about 4 or so weeks later the unit is now intermittently working. It periodically gets stuck in the on position and will only turn off after tapping vigorously on the case. This is similar to other reviews here. Amazon is sending a replacement but I am a bit worried I will be in the same boat a month from now. Poor quality product for the money - reliability is not there unfortunately. Update 2: Got the new unit and its been in place for the last 3 or so weeks. Seems to be working as designed - no more stuck on modes - but only time will tell. Uping my star count a bit because it is better - lets see... Update 3 (the last one): Replaced unit is 3 weeks in and beginning to fail in the same way - stuck on. if you knock on the case it will turn off. Don't buy this - not worth the premium price if you need it to work every time. ... show more
Reviewed in the United States on November 25, 2025 by Jeffrey Gathe
    • Understand how pressure switch works and where to install it
This pressure switch works great to activate a duct booster fan to move more air to upstairs bed room and bathroom. Install switch in a duct other than the one that has booster fan. Tried in duct with fan and it cycled on and off !! Excellent way to activate fan without an electrician Or wire yourself and burning up furnace electrical panel!!! ... show more
Reviewed in the United States on November 9, 2025 by Hank Kamna
    • Easy to install & works!
This HVAC pressure switch works flawlessly! Needed two in-line duct booster fans and this switch works perfectly to operate both!
Reviewed in the United States on August 19, 2024 by Ashley

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