How to Test Defrost Control Board

 On our board here. Um, so as you can tell, I have our thermostat in heat. Uh, we've got our electric heat strips on, um, because this is a Goodman, our reversing valve is not powered in heat. So this is normal, normal, uh, operating, uh, for a Goodman. Uh, your reversing valve is, is off. But what we wanna cover today is your defrost control board.

So this is a defrost thermostat and at 40 to 42 degrees, um, this switch is normally open and at 40 to 42 degrees, this switch will close, which will then complete the circuit causing our defrost board to go into defrost. Uh, and what that will do, uh, in this instance is that will turn on your reversing valve, which will, which will reverse the flow of refrigerant through the system, which will then heat up the outside coils to melt any ice, uh, to get anything off of your condenser, your heat pump, uh, so that it can run efficiently.

And then once your. Line set. Once this, this small line heats back up to around 70 degrees, the switch will pop back open and kick it out of defrost. But in order to test that, these, uh, boards have a test feature right here. There's a little, uh, I don't know how you can see. There we go. Uh, you can take this pin off right here and then we're gonna put it on the top terminal where it says, test.

Now, it'll take it a second, but all we're doing right here is we're tricking the system into thinking that this thermostat has closed. Okay. You hear that? So our switch has clicked. Uh, this came on for a second, but then turned back off. So this just lets us know that we're good because the temperature.

Is where it needed to be. So it didn't stay open for long, or it didn't stay closed for long. But there you go. That's how you would test your defrost control board.