Fixing a Stuck AC Relay Switch: How It Works

Premier Systems
April 30, 2023

When temperatures are high, your air conditioner is essential to your residential or commercial building’s comfort. Without the cool and refreshing air from your AC unit, the indoor environment can quickly become muggy. With so many moving parts, your air conditioner could malfunction and require repair at any time.


Among the components that could jeopardize your air conditioner's operations is the relay switch. A stuck AC relay switch prevents your air conditioner from turning on and lowering your indoor temperature to a comfortable level. Fortunately, there is a straightforward solution to fix a stuck AC relay switch and restore your comfort.


Below, we describe what an AC relay switch is, how to tell if it’s stuck, and the steps for fixing a stuck relay switch. When you need professional assistance to repair or replace a stuck relay switch, trust the AC repair  experts in Bozeman at Premier Systems. Call us today at 406-351-6585 to schedule an appointment. 


What Is an AC Relay Switch?

An AC relay switch is an electronic device that opens and closes to control the electricity flow to your air conditioner. The relay switch closes when you turn your air conditioner on, allowing electricity to flow, and closes to interrupt the circuit when you turn your unit off. A working relay switch helps improve your building’s energy efficiency


If you need to locate your AC relay switch in order to inspect or fix it, find your outdoor AC unit. The relay switch typically looks like a small electrical panel or box with three wires: an input wire, a power feed wire, and a ground wire. 


How to Tell if Your AC Relay Switch Is Stuck

Your AC relay switch can, unfortunately, become stuck in one position. It can then prevent your air conditioner’s fan and blower motor from receiving enough power to function, causing an AC system malfunction. If your AC relay switch is stuck, you should notice one or more signs of power source and operational failure, such as:


  • Your air conditioner won’t turn on.
  • Your air conditioner turns on but then turns off without reason.
  • Strange clicking noises are coming from your AC system.
  • Upon inspection of your AC relay switch, you see significant debris or damage.


Steps for Fixing a Stuck AC Relay Switch

If your AC relay switch is stuck, it’s best to trust HVAC experts to fix it. Because of the electricity involved, dealing with a relay switch without professional skills and equipment is dangerous. Experienced technicians with knowledge of contact resistance and circuit breakers can safely address the component.

Our experts at Premier Systems use the following steps to efficiently fix a stuck AC relay switch:


Step 1: Thoroughly Clean the Relay Switch

Dust, dirt, and debris are perhaps the most common reasons why AC relay switches get stuck. When the relay switch becomes dirty enough, it can’t move the way it should. Since the relay switch is on the outdoor AC unit, it can easily accumulate different types of debris over time.


To thoroughly clean the relay switch, we’ll remove it from the unit. Taping over the wires can help prevent any damage. We’ll then clean the connectors and the relay with a rag and alcohol or vinegar, making sure to rinse and dry the relay switch before reattaching it. 


Step 2: Inspect the Relay Switch for Damage

If cleaning the AC relay switch doesn’t do the trick, it could be damaged. Our professionals can inspect the component and its wires for damage and diagnose the issue.


Step 3: Replace the AC Relay Switch

If the AC relay switch is indeed damaged, you’ll likely need to replace the component. Upon inspection, our professional HVAC technicians can pinpoint the precise relay switch that fits your AC unit so that there are no problems during replacement. We can then remove your current AC relay switch and install the new one during an efficient, cost-effective appointment. 


How to Prevent Your AC Relay Switch From Becoming Stuck or Damaged

There are two main methods for preventing your relay switch from becoming stuck or damaged. 


The first is to use your air conditioning system in moderation. Opening the windows while there’s a nice breeze or turning the air conditioner off while you’re away from home can help prevent components from overheating and sticking. The second is to routinely clean the outside unit to prevent dirt and debris accumulation. 


Call Premier Systems Today

Whether your AC relay switch is stuck or your AC is not blowing cold air, our technicians at Premier Systems have the solutions to help. Call us at (406) 351-6585 to schedule an HVAC appointment today. 

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