Signs Your AC Needs Repair in NH

Updated 2026-09-30

An air conditioner in New Hampshire sits idle for most of the year and then has to work through a humid stretch that may last two weeks or two months. These are the signs that the next call is a repair, not another filter and not a new system by default. Call (603) 420-0791 with your ZIP code and what you see. An independent contractor quotes the repair after they find the cause. Confirm license and insurance. This site does not diagnose over the phone.

Warm air

The blower runs and the air is not cold. Check that the thermostat is set to cool and that the setpoint is below the room temperature. Check the breaker and the outdoor disconnect if you can do that safely. If the outdoor unit is silent, the problem may be a capacitor, a contactor, a breaker, or a board. If the outdoor unit runs and the air is still warm, the problem may be airflow, refrigerant, or a compressor that is not compressing. Those are different prices. Do not add refrigerant from a hardware-store can.

Ice

Ice on the copper line or a coil that looks like a snowball means stop. Turn the system off and let it thaw. Common causes are a dirty filter, a collapsed return, a failed blower, low charge, or a coil packed with dirt. Running the system while it is iced can destroy the compressor. After it thaws, if it ices again the same day, call. Cleaning may be part of the fix. It is not the whole fix if the charge is low.

Short cycling and noises

A condenser that starts and stops every few minutes is short-cycling. Causes include a failing capacitor, a refrigerant problem, a clogged coil, or a thermostat location in a draft. A new rattle, a scream from the outdoor fan, or a buzz that ends in a tripped breaker is a repair call. A soft hum on a hot afternoon can be normal. If you cannot tell, shut it off and describe the sound when you call. A recording helps the contractor and does not replace the visit.

Water

A pan that overflows or a stain on the ceiling under an air handler is a drain problem until proven otherwise. Algae, a sagging trap, or a failed condensate pump are typical. Water near electrical parts is urgent. Shut the system off. In a finished basement under a first-floor air handler, the leak may be a long way from the stain.

Smells

A dusty smell on the first hot day is often dust on a heater or a coil. A burning smell, or a smell that stays, is not. Shut the system off. If you see smoke or you suspect an electrical fire, use the emergency number. Do not wait for a referral line to tell you that.

What actually changes the repair quote

The part that failed, the refrigerant on the nameplate, how old the system is, and how hard the coil is to reach. R-22 systems are a special case because the refrigerant is no longer made for new equipment. A large leak on an R-22 system is often a replacement conversation. A capacitor on a ten-year-old R-410A system is often a repair. Access in a tight side yard, an attic air handler, or a condo with rules about the outdoor unit adds time. July schedules add waiting, not a different diagnosis.

We do not print a dollar range for these repairs. No source we will cite lists one New Hampshire price for a capacitor and a compressor. Ask the contractor what the quote includes. If the same repair has already been done recently, read when to repair or replace before you approve it again.

What to say when you call

ZIP code, whether the outdoor unit is running, whether there is ice, and when it last worked. The service page is AC repair. Cleaning, if the coil is the whole story, is AC cleaning. The contractor quotes the price. People in photos are actors or models. This site does not warrant the repair.

After the repair, watch one hot afternoon

When the system is back on, feel the supply air, listen to the outdoor unit, and check the drain for an hour if the failure involved water. A repair that "worked" on a mild morning can ice up on a humid afternoon if the airflow problem was not actually fixed. Tell the contractor if it returns the same week. A warranty on the repair should say how long labor is covered, not only the part. If ice returns, shut the system off again. Do not keep running it to prove a point.

Filters are the homeowner half of the repair. Ask for the size and the maximum restriction. A filter that is too fine, installed the evening after a coil cleaning, can recreate the freeze. Write the size on the air handler. Future you, and the next contractor, will use it. If the same symptom returns next summer, the note from this summer is the difference between a new diagnosis and a repeated guess.

Humidity is the clue people skip. A system that cools the thermostat but leaves the house clammy may be short-cycling, oversized, or low on airflow. That is still a reason to call. Comfort is not only the number on the wall. Note whether the problem is worse on the second floor or in one room. A single stale room can be a closed damper or a failed duct, not a failed compressor. Mention it. The contractor should not have to discover your floor plan by surprise. If you have already replaced the filter and checked the thermostat batteries, say that too, so the visit starts at the equipment instead of at the hallway.

If the system is still cooling, you can often wait a day and write the symptoms down. If it is icing, leaking onto electrical parts, or tripping a breaker, stop it and call. Those are the cases where waiting costs a compressor or a ceiling. Have the ZIP code ready. The contractor quotes after they see it. You confirm insurance before they start. Nothing on this page is a remote diagnosis or a price. Note whether the problem is the whole house or one room so the visit starts in the right place.

Signs your AC needs repair in New Hampshire