How Do I Know If My AC Refrigerant Is Low?

Short answerWe don't expect you can confirm it yourself. Warm air from the vents is one possible sign, but we expect a clogged filter or leaky ducts can look the same. We recommend a trained HVAC technician measure it. Trane says a properly running system shouldn't need refrigerant replaced, so low refrigerant points to a leak that needs repair.

What this costs

Our national estimates, not quotes.
Option	Job	Low	High
Replace	AC Replacement	$3,800	$9,050

Why low refrigerant means something is wrong

Trane says a properly running system shouldn't need its refrigerant replaced, though leaks can develop over time. DOE gives the same advice for a system that is low or leaking: call a trained technician to repair the leak and recharge the system.

Rule out the easy causes first

DOE lists other problems that cut cooling. We consider these safe to check before you pay for a visit.

Filter: a clogged one restricts airflow.
Thermostat: make sure it's set properly and reading correctly.
Drain: make sure your unit's drain isn't clogged.

What to ask the technician

Trane warns against any dealer who only refills and leaves, because the level will drop again and you'll pay again.

Did you measure the refrigerant level, and what did you find?
Where is the leak, and can it be fixed?
What refrigerant does my system use?
How do the repair and a replacement compare on a system this old?

Don't try to add it yourself

We recommend a licensed HVAC technician for refrigerant. EPA's Section 608 program also bars people from intentionally venting refrigerants, including HFCs, when servicing, repairing or disposing of this equipment. We don't give steps for this work.

AC Not Cooling? What to Check Before You Call

Common questions

Can a dirty filter feel like low refrigerant?

It can look similar, since DOE says a clogged filter reduces the unit's ability to cool the air. Replace a dirty filter first, then call a technician if the problem stays.

Will refrigerant get harder to find?

EPA says availability of these refrigerants and parts may decline over time as they are phased down. Its page doesn't give a date or price.