A Quick Guide to Coleman Mach Air Conditioner Troubleshooting

Coleman Mach, a subsidiary of the Airxcel family, specializes in crafting top-tier air conditioning systems designed specifically for RVs and campers. These systems are renowned for their exceptional compactness, energy efficiency, and robust performance.

However, owing to their compact dimensions and heavy reliance on electronic components, Coleman Mach air conditioners occasionally encounter operational issues that necessitate troubleshooting.

Common problems, such as AC not powering on or off, inadequate cooling, or sluggish airflow, can often be resolved through do-it-yourself methods.

Conversely, issues related to the thermostat, compressor malfunctions, refrigerant leaks, or motor failures may necessitate the expertise of an HVAC technician for proper diagnosis and resolution.

Before jumping to the troubleshooting guide, I recommend you reset your Coleman Mach Air Conditioner. Start by turning off the thermostat. Then, find and remove the fuse inside the unit, leaving it disconnected for about 5 minutes. Afterwards, reinsert the fuse securely and wait another 5 minutes. Lastly, switch the thermostat back on to complete the reset.

Quick Summary of Coleman Mach Air Conditioner Troubleshooting Guide

Problem	Possible Causes	Solution
1. AC Not Turning On	Power outage, Unplugged unit, Tripped breaker, Blown fuse, Non-responsive remote, Faulty wiring, Faulty thermostat, Bad run capacitor	Check for a power outage, Ensure proper plug connection, Reset breaker, Replace the blown a fuse, Replace remote batteries, Inspect wiring, Troubleshoot thermostat, Check run capacitor
2. AC Not Turning Off	Dirty condenser coils, Defective thermostat, Defective thermistor, Bad relay board, Failing temperature control board, Failed control board	Clean condenser coils, Replace faulty thermostat, thermistor, relay board, temperature control board, or control board
3. AC Not Cooling	Dirty air filter, Dirty outdoor unit (condenser coils and compressor), Incorrect thermostat setting, Inadequate AC size, Low refrigerant, Broken fan, Faulty thermostat, compressor, or control board	Clean air filter and outdoor unit, Adjust thermostat setting, Upgrade AC size, Check and replenish refrigerant level, Replace broken fan or faulty components
4. AC Not Heating	Power disruption, Dirty filter, Incorrect thermostat setting, Frozen coils, Leaky refrigerant, Faulty wiring, Failed heat slip, Faulty fan	Reset breaker and replace blown fuse, Clean air filter, Adjust thermostat setting, Thaw frozen coils, Fix wiring or refrigerant leak, Replace faulty components
5. Compressor Not Working	Frost build-up, Dirty coils, Burnt overload, Bad thermostat, compressor, or temperature control board	Thaw frozen coils, Clean coils, Replace overload, thermostat, or control board if needed
6. Fan Not Working	Worn-out or defective fan motor, Bent fan blades, Burnt thermostat or blower motor, Failing relay board capacitor, or control board	Replace worn-out or defective components
7. Noisy Air Conditioner	Loose components, Debris in the fan or blower, Damaged fan blades, Worn-out motor bearings	Tighten loose components, Remove debris, Repair or replace damaged fan blades, Lubricate or replace worn-out motor bearings
8. AC Leaking Water	Clogged condensate drain, Frozen evaporator coils, Improper installation, Dirty air filter, Damaged or disconnected drain pan	Unclog the condensate drain, Thaw frozen coils, Ensure proper installation, Clean or replace the air filter, Repair or reconnect the drain pan
9. AC Cycling On and Off Frequently	Dirty or blocked air filters, Incorrect thermostat settings, Low refrigerant levels, Faulty thermostat, Airflow restrictions, Oversized unit	Clean or replace air filters, Adjust thermostat settings, Check and refill refrigerant levels, Replace faulty thermostat, Remove airflow restrictions, Consider resizing the unit

9 Mach Air Conditioner Troubleshooting [Coleman Mach AC Not Working]

After summarizing the Coleman AC troubleshooting, let’s delve into the specifics,

1. Coleman AC Not Turning On

Several issues may be at play when your Coleman Mach Air Conditioner refuses to turn on.

Each of these causes needs to be addressed differently. Here is how to deal with individual cases,

Insufficient power supply is often caused by a power outage in your area. To address this, check for a local power outage or ensure your AC unit is properly connected.

A loose or disconnected power cord may also be the culprit. Verify secure connections between the AC unit and the power source in this case.

An overloaded circuit or electrical fault can lead to a tripped breaker, preventing the AC from starting. To resolve this, locate and reset the tripped breaker, but consult an electrician if it continues to trip.

Blown fuses, resulting from overcurrent or a short circuit, can disrupt the AC’s operation. Inspect the fuses in the AC unit or its electrical panel and replace any blown fuses with ones of the same rating.

If your remote control is non-responsive, it could be due to dead or low batteries in the remote. Replace the remote batteries and ensure it’s properly synchronized with the AC unit.

Damaged wiring caused by wear, rodents, or physical damage can lead to power supply issues. To address this, inspect the wiring connections for any damage or loose connections and replace or repair damaged wires as needed.

A malfunctioning thermostat with faulty components or incorrect settings may prevent the AC from turning on. Check the thermostat settings to ensure they are correct, and if it still doesn’t work, you may need to replace the thermostat.

Finally, a defective run capacitor can hinder the AC’s startup. For this issue, consult a professional HVAC technician to test and potentially replace the run capacitor.

2. Coleman AC Not Turning Off

If your Coleman Mach Air Conditioner won’t turn off when it should, it could be due to various factors. These issues may arise from insufficient maintenance, wear and tear of components, or electrical problems.

Potential causes include dirty condenser coils, a malfunctioning thermostat, a defective thermistor, a faulty relay board, a failing temperature control board, or a damaged control board.

To address this problem effectively, you should consider the following steps:

1. Clean the condenser coils: Accumulated dirt and debris on the condenser coils can interfere with the unit’s ability to shut off properly.
2. Replace faulty components: Based on a professional diagnosis, replace malfunctioning components such as the thermostat, thermistor, relay board, temperature control board, or control board.

3. Coleman AC Not Cooling

What’s the use when your Coleman Mach Air Conditioner isn’t cooling properly? It can be due to various reasons, including insufficient maintenance, installation problems, or component failures.

Moreover, other causes include a dirty air filter, outdoor unit dirt accumulation, incorrect thermostat settings, improper AC unit size, low refrigerant levels, a malfunctioning fan, or faulty components like the thermostat, compressor, or control board.

To address this problem:

1. Clean the air filter for better airflow.
2. Remove dirt from the outdoor unit components.
3. Adjust thermostat settings.
4. Consider upgrading to an appropriately sized AC unit.
5. Check and refill refrigerant levels if needed.
6. Replace malfunctioning components for optimal cooling.

4. Coleman AC Not Heating

When you’re counting on your Coleman AC to provide warmth on a bitterly cold day, it can be quite disheartening when it falls short of your expectations.

The reasons can be power disruptions, maintenance lapses, or component problems. Possible issues include tripped breakers, a clogged air filter, incorrect thermostat settings, frozen coils, refrigerant leaks, faulty wiring, or malfunctioning heat strips or fans.

To fix this:

1. Reset breakers and replace blown fuses.
2. Clean the air filter for better airflow.
3. Adjust thermostat settings.
4. Thaw frozen coils if necessary.
5. Address any faulty wiring or refrigerant leaks.
6. Replace malfunctioning heat strips or fans to restore heating.

5. Coleman AC Compressor Not Working

The AC compressor functions as the heart of the unit. If it fails, the AC won’t be able to condition the air properly, resulting in little more than air circulation within the space.

Coleman Mach Air Conditioner’s compressor fails to function due to various factors, including maintenance lapses, electrical issues, or component failures.

Common causes include frost on the coils, dirty coils reducing compressor efficiency, a burnt overload in the electrical system, a malfunctioning thermostat, or temperature control board problems.

To address this:

1. Thaw frozen coils to remove the obstruction.
2. Clean the coils to enhance compressor efficiency.
3. Replace a burnt overload in the electrical system.
4. Check the thermostat for malfunctions and replace if needed.
5. Replace the compressor if it’s confirmed to be faulty.
6. Inspect the temperature control board and replace it if it is causing compressor issues.

6. Coleman AC Fan Not Working

There is no airflow When the fan in your Coleman Mach Air Conditioner isn’t working. This makes the AC useless.

The AC fan may not work due to component wear, electrical faults, or damage.

Other possible causes include a worn-out or defective fan motor, bent or damaged fan blades, a burnt thermostat or blower motor, or failing relay, capacitor, or control boards responsible for fan operation.

To fix this:

1. Inspect the fan motor and replace it if it is worn out or defective.
2. Check for bent or damaged fan blades and straighten or replace them if necessary.
3. Examine the thermostat and blower motor for damage and replace if needed.
4. If the issue lies with the relay board, capacitor, or control board, replace the faulty component.

7. Coleman Noisy Air Conditioner

When your Coleman Mach Air Conditioner is operating noisily, excessive noise can stem from several factors related to wear and tear, improper maintenance, or physical damage. Common causes include:

• Loose components within the AC unit.
• Debris lodged in the fan or blower.
• Damaged or bent fan blades.
• Worn-out motor bearings that create friction and noise.

To effectively address this issue, consider implementing the following solutions:

• Inspect the AC unit for loose components and tighten them to eliminate rattling or vibrating parts.
• Remove debris or foreign objects from the fan or blower to restore smooth airflow and reduce noise.
• Examine the fan blades for damage or bending, and repair or replace them to ensure they rotate without creating noise.
• Lubricate or replace worn-out motor bearings, which can reduce friction and minimize noise during operation.

8. Coleman AC Leaking Water

A leaking water from Coleman AC is enough to destroy your whole RV experience. Over time, the leaking water will keep damaging other critical components.

The potential causes often stem from poor maintenance, installation errors, or

1. Clogged Condensate Drain: Ensure proper drainage by unclogging the condensate drain to prevent water backup and leakage.
2. Frozen Evaporator Coils: Thaw frozen coils to reduce condensation and stop leakage.
3. Improper Installation: Correct installation errors to facilitate proper drainage and prevent leaks.
4. Dirty or Clogged Air Filter: Maintain optimal airflow by regularly cleaning or replacing the air filter to prevent condensation buildup.
5. Damaged or Disconnected Drain Pan: Inspect the drain pan for damage and make necessary repairs or reconnections to prevent future water leakage.

9. Coleman AC Cycling On and Off Frequently

“Cycling on and off” refers to an air conditioner repeatedly turning on and off quickly.

This can lead to inefficiency, inconsistent temperatures, increased wear, and higher energy costs. Identifying and addressing the root causes, such as airflow or thermostat issues, is essential to maintaining comfort and energy efficiency.

If your Coleman Mach Air Conditioner is frequently cycling on and off, it may be due to various factors, including:

1. Dirty or Blocked Air Filters: Clean or replace the air filters to restore proper airflow and prevent overheating.
2. Incorrect Thermostat Settings: Adjust thermostat settings to more appropriate temperatures to reduce frequent cycling.
3. Low Refrigerant Levels: Check refrigerant levels and refill if low to ensure proper cooling operation.
4. Faulty Thermostat: Replace a faulty thermostat to ensure accurate temperature regulation.
5. Airflow Restrictions: Remove any airflow restrictions within the system to allow for smooth operation.
6. Oversized Unit: Consider resizing the unit to match the cooling needs of your space better.