Why doesn’t my RV air conditioner not keeping my RV cool enough?

RV AC diagnostic assessment.

It’s hot here in North Texas! We have been experiencing triple digit temperatures for over 20 consecutive days and counting.
Many standard RV air conditioners are struggling to keep the RV cool.
Let’s talk about why this happens, but before we list the reasons, it’s important to understand that any of these conditions can cause your RV air conditioner to perform poorly and sometimes there’s multiple reasons

Dirty air filters and/or coils

Dust, dirt, and debris can accumulate in the air filters and coils, reducing the AC’s efficiency. Be sure to clean your filter at least once a month and have your coils cleaned annually to improve your AC’s efficiency. Please note: Aftermarket filters aren’t always the answer, because thicker filters can restrict airflow.

Airflow issues

Obstructions or blockages around the AC vents or inside the unit itself can cause airflow issues. If the return and supply airflow bleeds together from poor seals or a faulty divider, it can cause something called short-cycling; the mixing of warm and cold air.

Electrical Problems

Problems with the electrical connections, wiring, or circuitry can prevent the AC unit from functioning correctly. This can lead to reduced power to the compressor or other components.

Overworked AC unit

Extremely hot weather can put a heavy load on your RV’s air conditioning system, causing it to struggle to maintain a comfortable temperature.
A properly working AC should measure a temperature differential of 14°-22°F. If the interior temperature of the RV is 80° and the supply airflow is 60°-66°F, your AC is working as expected. As the return air temperature decrease, so will the supply output air.

In more extreme situations, the compressor may shut down when the overload protection circuit is triggered. Some common reasons this happens is overheating and excessively long run time. After a few minutes or when the problem gets corrected, the compressor will turn back on and start cooling, but the temperature has increase making it even harder for the AC to lower the temperature in the RV.

High humidity

Air conditioners are designed to remove moisture first, then cool. When the humidity is high, the AC feels like it’s not cooling effectively.

Low refrigerant

If the refrigerant levels in your RV AC are low, it can hinder its ability to cool effectively. Unlike residential ACs, RV ACs are closed systems; that means RV ACs should never be recharged with refrigerant. There are people that may recharge RV ACs. This is not supported by the manufacturer and is not considered safe.


RV AC compressors are a critical part of the AC system. The compressor uses refrigerant to remove heat, which in turn provides cold air into the RV.

Poor insulation

RV are not insulated the same as residential houses. Thin walls and minimal insulation allow the heat to radiate in and quickly increase the interior temperature. When this happens, the AC will struggle to maintain a comfortable temperature.

Leave a Comment

Your email address will not be published. Required fields are marked *