Solved!!Contactor Works When Pushed In: Causes and Solutions

If your AC’s contactor is not pilling automatically, it is certainly overwhelming. Here, I provide a DIY process to resolve the issue.

While using ACs, we eventually face a problem with the contactor that has stopped automatically pulling in. It is an overwhelming and very risky context, as it can trigger electrocuting when you manually push in.

Now, the question is why contactor works when pushed in. The reasons for this are;

The contactor coil is burned

Faulty wiring connections

The drain pipe is obstructed

Connection issue at the thermostat end

The contactor coil is not receiving power from the control board

Contact surfaces are holding rust, etc.

To solve the issue, I suggest you start by checking the contactor and thermostat connection. Then go for a health checkup of the contractor itself. If there is any wiring or faulty issue, do reconnection or replacement accordingly. Finally, check if the contactor’s working surface is corroded. Upon finding such, clean the surface.

Here, I describe the problems in detail to make it understandable. Additionally, I provide a stepwise guideline while incorporating causes and solutions.

Table: Reasons vs Solutions

The below table provides a quick overview of the issue’s causes and solutions.

Contactor Works when Pushed In: Causes and Solutions

In this section, I inform you of the causes of the issue in a detailed manner while elaborating on DIY guidelines.

Disconnection from Thermostate End

To complete the circuit, the contact must receive electrical signals from the thermostat. Sometimes due to mechanical and electric faults, the connection from 24 VAC at the thermostat end can get damaged.

It results in obstructing the electric signal passing to the contactor. The AC’s contactor cannot function to automatically pull in the plunger.

Solution

Here is the step-by-step guideline to solve it.

Step 01: Remove the thermostat covering

Step 02: Use a multimeter to check the connection’s status at the thermostat’s R, R, and Y terminals. It should display 24 Volt.

Step 03: If low or no voltage shows, the thermostat is not receiving power.

Step 04: Use a screwdriver to take out the wire from the terminal.

Step 05: Cut off the edges of the wires and create a new open-wire surface by getting rid of the plastic covering.

Step 06: Reconnect the wire with the terminal.

Step 07: Check the status of the contactor.

If not working automatically, go for the next cause and solution.

Contactor Coil is not Receiving power

If the contactor is functioning, there is also a chance that its coil is not getting power from the control board. In general, due to mechanical and electrical faults, this disconnection happens. Here, mechanical faults orient because of human errors that happen during establishing the connection. And the electrical fault originates due to an excessive amount of electricity flow.

Solution

Below is the checking and resolution process.

Step 01: Open the control board.

Step 02: Identify the R and Y terminals on the control board.

Step 03: Use a multimeter to check the connection status. The connection needs to redo if there is no or low voltage on the multimeter.

Step 04: Take out the inserted wire and cut off the edge. Create an open wire at the new edge of the wire to re-establish the connection.

Step 05: Make the connection and check the contactor status by powering up the AC.

Contactor Coil is Burned

The coil at the contactor is the heart of the whole system. Upon receiving the power, the coil creates the magnetic field to pull in the metal plunger. If the contactor coil is burned, it won’t be able to pull in the yellow plunger by itself. The reason for coil burn is excessive electricity pass.

In this case, first, you have to check the coil’s status to be sure it is burned. Second, upon finding the burning sign, you have to replace it.

Solution

Follow the below stepwise guide to deal with the coil-burn issue.

Step 01: Make sure to switch off the power to the air handler as well as your AC condensing unit.

Step 02: Open the electrical box on the side of your AC condensing unit.

Step 03: You’ll find the contactor coil’s connections on the left and right sides of the contactor. I suggest you click a photo of the wire connection to get visual assistance when reconnecting.

Step 04: After that, detach the wires from the contactor coil’s connections.

Step 05: Set your digital multimeter or analog meter to measure ohms. If the coil is not burned, it will come up with a resistance of 10–20 ohms. If below 10 ohms, you have to replace the coil.

Step 06: Purchase a new coil as per the brand of the contactor. And snap it inside the respective slot of the device.

Step 07: Finally, power up the system and check whether the contactor’s issue is gone.

Faulty Wiring Connections at Contactor End

If any connection is worn out or loose, the contractor won’t be able to function correctly. Also, it eventually hosts a “chattering” context. It means the yellow plunger is engaging and disengaging simultaneously. And as a result, you need to push it manually.

Solution

The following are the resolution approaches.

Step 01: Power off the whole system.

Step 02: Check all the connections and take a picture to do reconnection perfectly.

Step 03: Use a screwdriver to remove the connecting screws at the terminals.

Step 04: Take out the connecting wires.

Step 05: Cut off the old connection arrangements.

Step 06: Make a new connection arrangement using new ring connectors and conductive studs.

Step 07: Now, establish the connections. Tighten the screws appropriately.

Step 08: Check the status of the contractor.

Check out this YouTube video, to deal with the contactor connection issue: https://www.youtube.com/watch?v=YCygHajsW34

Drain Piping is Stuck

If the respective condensate drainage system is obstructed due to the disposition of slime, dust, debris, insects, etc., it can restrict the contactor’s function. The blockage usually orients if you do not clean it in a timely manner.

Also, if you are a resident of Texas or Arizona, insects like ants, etc., eventually go inside the piping and clog that drain system. However, in the case of condensate drain blockage, it activates the condensate switch.

Following this, the power supply to the contactor AC is cut down, and it loses the ability to function automatically.

Solution

The following is the detailed guidance to solve the drain collar issue.

Step 01: Locate the “vent tee” at the air handler.

Step 02: Remove the cap of the “tee.”

Step 03: You will see some solid depositions.

Step 04: Now, depending on the type and volume of the disposition, use a dry, wet, or drain gun to clean the drain pipe.

Step 05: Wash the pipe with clean water first. Then use vinegar to clean the pipe again.

Step 06: Fix the pipe and power up the machine. Check the status of the issue.

Rust on Contact Surfaces

Over time, the contact surfaces of the contactor can host rust due to electric arcs’ formation while engaging and disengaging. It is a very common happening following the basic characteristics of metals. And contractors from most reputed brands are also excluded from this unwanted event.

Solution

The cleaning of rust is very tough as the space between two surfaces is very narrow. The reason is that even after the use of rust-removal spray, you won’t be able to wipe out the dissolvent from every fold and corner.

So, if the rust is very little, use the rust spray. But, if the rust disposition is too large, change the contactor. Disconnect the contactor by following the process mentioned in the “repairing faulty connection” section. And install a new contactor.

Finally, reconnect it.

Advice When Applying the Solutions

I suggest you consider the below advice when implementing the solution;.

• While working on the fixings, it is essential to wear proper personal protective equipment (PPE).
• If it is raining or snowing, do not work on the outdoor unit.
• Keep your children at a safe distance.
• Always use a high-quality multimeter and ohm-meter to check the connection and resistance status.
• While fixing the drain pipe clogged issue, take conscious measures to prevent pipe damage due to high air pressure or the blower’s heat.

People Also Ask

Here, I answer some most common questions.

What are the signs of a bad AC contactor?

If the contactor is producing humming or chattering noises, it is for sure that the contactor is faulty. Also, if there is any melting or burning sign, then the contactor is bad.

What is the possible damage level of a contactor?

Overvoltage passing is the most common cause of fully damaging the contactor. Eventually, the overvoltage generates higher temperatures and causes the melting of material components of the contactor.

What is the lifespan of an air conditioner contactor?

Well, the lifespan of the air conditioner contactor depends on its brand and quality. In general, a standard one can survive for 8–10 years.

Final Words

I hope that now you have a clear understanding of why the contactor works when pushed in. By applying the solutions, you can resolve the issues effectively. It does not require an expert level of knowledge. But, you have the basics of handling electric devices and connections.

Finally, I want to warn you not to avoid the issue for a longer period; pushing the contactor manually is risky. Also, I strongly recommend you use appropriate protective gear while applying the addressing approaches.