Hiring an HVAC technician: licensing, EPA 608 and quotes

When the house won't heat or cool, it feels urgent, and it often is. But a lot of HVAC service calls end with a new filter, a thermostat setting or a breaker that needed resetting. A few minutes of checking can save you a visit, and tell you what to say when you do call.

When the problem is inside the equipment, though, an HVAC technician is the right person. Their work involves high voltage, gas burners and refrigerant under pressure, and federal rules control who can handle that refrigerant.

What an HVAC technician does, and doesn't do

HVAC stands for heating, ventilation and air conditioning. Technicians install, maintain and repair:

Central air conditioners and heat pumps
Gas, oil and electric furnaces
Ductless mini-splits
Thermostats and system controls
Ductwork, vents and ventilation fans
Seasonal tune-ups and safety checks

Many HVAC companies don't do general electrical work outside the system, or plumbing beyond condensate drains. Some also service water heaters, but many don't, so ask. Window air conditioners and refrigerators are usually appliance repair territory.

HVAC jobs you shouldn't DIY

Anything involving refrigerant. Adding, removing or recovering refrigerant from home AC and heat pump systems requires EPA certification (more below).
Gas burners, gas valves and gas piping. Never DIY gas work. Pilot relighting only if the furnace's own label tells you how.
Electrical repairs inside the units. Capacitors in outdoor units can hold a charge even with power off.
Cracked heat exchangers or carbon monoxide concerns. If a CO alarm sounds, get everyone outside and call 911.
Installing or replacing equipment. Sizing, venting, permits and refrigerant handling all apply.

Homeowner-safe checks to try first: change your HVAC filter, thermostat not working and AC not cooling.

EPA Section 608: the refrigerant rule

Under Section 608 of the Clean Air Act, the EPA requires anyone who maintains, services, repairs or disposes of equipment that could release refrigerant to be certified. That includes attaching gauges to check pressure and adding or removing refrigerant, according to the EPA's certification page.

There are four certification types. Type I covers small appliances, Type II covers high-pressure and very high-pressure equipment, Type III covers low-pressure equipment, and Universal covers all three. The certification doesn't expire. You don't need to know which type applies to your system; just ask the technician to confirm they're certified for the equipment they'll be working on.

The EPA also restricts who can buy refrigerant. Refrigerant for home systems is sold to certified technicians and their employers, per the EPA's sales restriction. So if someone offers to "top off" your AC with no certification, that's a red flag. Ask any technician to confirm their Section 608 certification.

HVAC licensing

On top of the federal refrigerant rule, most states license HVAC or mechanical contractors, and many cities and counties require permits for equipment replacement. Rules vary by state and town, so check yours: search your state name plus "HVAC license lookup," then search the company or technician by name or license number.

In South Carolina, the Department of Labor, Licensing and Regulation (LLR) licenses residential HVAC contractors through its Residential Builders Commission, and you can check one with LLR's online Licensee Lookup. See how to check a contractor license for more.

What drives the cost

Repair or replace. A part swap and a new system are very different jobs.
Diagnosis and trip fees. Often charged, sometimes credited toward the repair.
Season and timing. The first heat wave and the first cold snap are the busiest times.
Refrigerant type and leaks. Finding and fixing a leak is the real work, not the refrigerant itself.
Equipment size, efficiency and brand. For replacements, these matter most.
Ductwork condition and access. Tight attics and crawl spaces add labor.
Permits. Common for equipment replacement.

Questions to ask before hiring

What's your state license number? Are your technicians EPA Section 608 certified?
Do you carry general liability insurance and workers' compensation?
Is there a diagnostic fee, and is it applied to the repair?
If refrigerant is low, will you find and repair the leak?
For a replacement, will you do a load calculation to size the system?
Will you pull the permit, and is it included in the price?
What's covered by your labor warranty, and how does it work with the manufacturer's warranty?

How to describe the problem for an accurate quote

Symptoms. "Upstairs is warm, downstairs is fine. Air from vents is cool but not cold."
Equipment details. Brand, model and age from the labels on the indoor and outdoor units, plus whether the furnace is gas or electric.
What you've checked. Filter changed, thermostat setting, breakers on.
Sounds and smells. Clicking, buzzing, grinding, burning dust, ice on lines.
Last service. When the system was last tuned up, if you know.
Photos. Of the unit labels, the thermostat and anything that looks off.

For replacements, get written estimates from more than one company. Our guide to comparing quotes shows what to line up side by side.

After the job is done

Ask the technician to show you what they found and what they fixed, and to point out where your filter goes and what size it takes. If they added refrigerant, ask whether they found and repaired the leak, and get that in writing. A system that keeps needing refrigerant still has a leak.

For a new system, register the equipment with the manufacturer if the warranty requires it, and keep the installation paperwork and permit. Set a reminder for seasonal maintenance with our maintenance calendar.

If you rent, heating and cooling systems usually belong to the landlord. Report problems to them in writing rather than calling a technician on your own.

Next steps

Try the fix-or-call quiz if you're unsure, read contractor red flags, or send a free match request to hear from local HVAC pros.

Common questions

Can I add refrigerant to my AC myself?

No. Under EPA rules, refrigerant for home AC and heat pump systems is sold to Section 608 certified technicians, and anyone who adds or removes refrigerant must be certified. Low refrigerant also usually means a leak that needs repair, not just a top-off.

What is EPA Section 608 certification?

It's a federal certification required for technicians who service equipment that could release refrigerant. There are four types based on the kind of equipment, and Universal covers them all. Ask the technician to confirm they're certified for your equipment.

What can I check before calling?

Check that the thermostat is set correctly and has power, replace a dirty filter, confirm the breakers are on, and make sure vents aren't blocked. If you smell gas, leave the house and call the gas utility or 911 from outside.

Do HVAC contractors need a state license?

Most states license HVAC or mechanical contractors, and many towns require permits for new equipment. Check the license with your state board before work begins.