When ERR shows up on the screen, this usually means the connection between the Control and it’s unit(s) isn’t working properly.


Since the issue is with the Crawlspace system I immediately think there are 2 system on that control, Crawlspace and Booster.


So, best bet is to simply try the crawlspace alone first to rule that out.

To do so, all you do is:

  1. Unplug the Crawlspace unit from the Wall
  2. Unplug the Booster Fan Unit from the wall.
  3. Unplug the connection wire from the Booster to the Controller.
  4. Plug the Crawlspace unit back in the wall.

What this does is you’ve removed the Booster fan from the equation.


Then check on the control, after a few minutes of boot up, does the control say ERR. If so, then the problem is the connection between the control or the crawlspace. (The 4-wire communication connection.)


If no ERR shows up, then you know that that works. So, the issue is somewhere with the booster.


So, If the problem persists do the following,

  1. Unplug the Crawlspace unit from the wall
  2. Reconnect the Communication Connector in the Booster Fan
  3. Connect the Booster Fan to the Wall
  4. Go check to make sure the Control power is Off (This is important, The Booster should not be powering the Controller)
    • If On:  The Jumper on the Electrical Board inside the Booster was placed wrong during manufacturing.
    • If Off:  Connect the Crawlspace to the Outlet and check if ERR shows up.
  5. If the ERR still shows up, the issue is within the communication connection of the Booster Fan, Double check the wires and makes sure they are appropriately connected to where they should be.