Why is My Caravan Air Conditioning Not Getting Cold?

Jul 12, 2025

Your Caravan or Motorhome Air Conditioning isn’t getting cold? Short answer: it’s likely low refrigerant, dirty filters, or a moody thermostat. Before you panic or punch the control panel, stick around—we’ll show you simple checks, fixes, and when it’s time to call the pros (not the exorcist).

The Simple Fixes You Should Try First

Checking Your Power Supply and Settings

Is Your Caravan Getting Enough Power?

Electrical problems are a common reason air conditioning units fail to cool. Issues such as a tripped circuit breaker, blown fuse, or unstable power supply can all stop your system from working effectively.

Start by checking the power supply to the unit. Inspect for any obvious wear or damage on the wiring and make sure all electrical connections are secure.

If you’re unsure, consult a professional.

TrTruma caravan roof air conditioner on a white background.

Verifying Your Thermostat and Control Panel Settings

A malfunctioning thermostat or control panel can lead to poor cooling performance. Make sure the thermostat is set to the correct temperature and cooling mode.

If the control panel isn’t responding or shows error messages, check the user manual or reset the system if possible. Faulty controls can prevent the unit from kicking into full cooling mode.

Clearing the Air: Filters, Vents, and Coils

How to Inspect and Clean Your Air Filters

Dirty or clogged air filters are one of the most common causes of poor aircon performance. When airflow is restricted, the unit can’t operate efficiently.

Remove the filters, wash them with mild soap and water, then let them dry completely before reinserting. Regular cleaning will help prevent larger problems down the line.

Checking for Blocked Vents and Ensuring Good Airflow

Check all interior vents to ensure they’re not blocked by furniture or debris. Poor airflow can cause uneven cooling or make the system work harder than necessary.

Keeping vents clear helps the aircon distribute cool air more effectively.

Woman using a Truma air conditioner remote control inside a caravan.

Inspecting and Cleaning the External Unit and Coils

The condenser and evaporator coils are essential for cooling. Dirt, dust, or debris on the coils can reduce their ability to transfer heat, leading to warm air inside.

Use a soft brush or coil cleaner to gently remove build-up without damaging the components.

Troubleshooting More Complex Issues

Identifying Potential Refrigerant Leaks

Signs of a Refrigerant Leak (Hissing Noises, Ice Build-up)

Low refrigerant levels prevent the system from producing cool air. Signs of a leak include ice on the evaporator coils, a noticeable hissing sound, or reduced cooling efficiency.

These leaks can be difficult to detect without specialised tools.

Why "Regassing" Isn't the First Step

Many assume topping up the refrigerant ("regassing") will fix the issue, but it's not a permanent solution. The system should never need regassing unless there’s a leak.

It's essential to find and fix the leak before adding more refrigerant — otherwise, the problem will return quickly.

Dometic caravan roof air conditioner on a white background.

Mechanical and Electrical Faults

Issues with the Compressor or Capacitor

The compressor is the heart of the air conditioning system. If it’s faulty, the unit may not cool at all.

Capacitors, which help start the motor, can also fail. These components require professional testing and replacement.

Problems with the Fan Motor

A broken or worn-out fan motor can stop the unit from blowing cool air. If you notice the fan isn’t spinning or hear unusual noises, this could point to motor issues.

Again, this is a job for a qualified technician.

When to Call a Professional for a Diagnosis and Repair

If you’ve tried all basic fixes and your caravan aircon still isn’t cooling, it’s time to call a professional. They’ll have the tools and expertise to check for deeper faults, test refrigerant levels, and safely repair electrical or mechanical issues.

Avoid DIY repairs on complex systems, as this can lead to further damage or void warranties.

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