Technicians Next to Binsky van

My AC Isn't Blowing Cold Air!

A common call we get from Warren homeowners is “My AC isn’t blowing cold air!”

So it was no surprise when Jane M., a homeowner in Warren, NJ, called saying that her Lennox AC was not cooling the 1st floor of her home.

In this customer story, we’ll explain:

  • Why Jane’s AC was not cooling
  • How we fixed it
  • How much it costs to fix

Diagnosing the AC not cooling

When our experienced technician, Randy, arrived, he first needed to find the cause of the problem. This is called performing a “diagnostic.”

After inspecting the system thoroughly, he found that the fuse on the circuit board popped.

For those of you who don’t know, fuses are the older version of a circuit breaker, which are designed to “trip” in case of an electrical overload.

So if the fuse popped, that means there was a bigger underlying problem that needed to be found and fixed.

Fixing the deeper problem

After Randy replaced the blown fuse, he had to troubleshoot the wiring, rewiring all connections from the circuit board to the condenser (the outside AC unit).

Finally he found and replaced a bad contactor.

It’s a small, but important part because if the contactor is broken, your AC won't cool your home!

AC contactors: A quick explanation

To understand what a contactor does, you need to know how an air conditioner normally turns on.

First, your thermostat senses that your home needs cooling. It then sends low-voltage power to the contactor, a mechanical relay switch.

The contactor switch closes a circuit to give power to your air conditioner’s condenser fan and compressor. The compressor is the “heart” of your air conditioning system. So if the compressor isn’t pumping cold refrigerant, your AC isn’t going to cool your home.

To put it more simply, think of how your AC works as a “conversation” between your system’s parts:

  • Thermostat: “Hey, this home is too hot. We need cooling! Contactor, here’s some power to get that started.”
  • Contactor: “Roger that! Now I have power to close this electrical circuit so we can power the air conditioner.”
  • Air conditioner: “Thanks. Now I have the power to turn on my compressor and condenser fan motor!”

But if the contactor is broken, there’s an “interruption” in the conversation between thermostat and the air conditioner and therefore the AC can’t start.

And AC contactors do often wear down and are therefore one of the most common AC failures.

Thankfully, contactors are easy to replace.

At any rate, once we fixed all the above issues, we got Jane’s system up and running again.

And boy was she thankful!

Note: Keep in mind that the cost and time to fix an air conditioner all depends on what’s wrong with it.

There’s no-one-size-fits-all approach. If your AC is having issues, the first step is always to have a professional diagnose what’s wrong.

It's just like how a doctor asks questions and diagnoses what's wrong with you before recommending a course of treatment to remedy the problem.

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