How do I know if my HVAC contactor is bad?

Bad AC Contactor Symptoms

  1. The condenser unit never shuts off. This could be a sign that the contactor has melted, leaving the air conditioner with no means to block electricity.
  2. AC hums and won’t turn on.
  3. AC makes a chattering noise.

What does a contactor do in HVAC?

The contactor on your AC unit is like a switch located in the AC system’s outdoor condenser unit. It provides power to components such as the compressor and condenser fan and turns the AC unit on and off. Contactors can fail electrically or mechanically.

How do you know if you have a bad contactor?

A bad AC contactor can be identified by physical signs of deterioration, also known as pitting. Pitting occurs when the contactor has encountered extreme voltage and heat. A pitted contactor tends to stick, causing a continuous flow of electricity to the unit.

What are the symptoms of a bad AC relay?

Common signs include inconsistent cooling, not hearing a click from the compressor turning on, and no cold air.

Which is better relay or contactor?

Relays are used in circuits that have load capacity equal to or smaller than 10 amperes, so spring load contacts are not commonly seen in relays due to their low load capacity. On the other hand, contactors have load capacities greater than 10 amperes which means that they can carry higher loads.

How does contactor relay work?

A contactor is a large relay, usually used to switch current to an electric motor or another high-power load. Large electric motors can be protected from overcurrent damage through the use of overload heaters and overload contacts.

What happens when a relay goes bad?

If your starter relay has gone bad, the electrical signal will never make it from the battery to the starter motor. As a result, your engine won’t turn over – no matter how many times you turn the key. A faulty relay often produces an audible clicking sound when you turn your car.