Seasonal tune-up and full diagnostic on your Carrier, Trane, or Goodman system - readings shown to you before any repair is proposed
Diagnosis first, numbers second - you approve the repair price before a single part goes in.
Before
After
Before
After
Before
AfterA/C Running Constantly and Never Shutting Off
An air conditioner that runs without stopping almost always means the system cannot reach the temperature you set on the thermostat. The three most common causes are a dirty air filter choking the airflow, a refrigerant leak starving the system of cooling capacity, or a frozen evaporator coil blocking heat transfer entirely. In most cases, a trained technician can diagnose the root cause in a single visit and give you a written repair price before touching anything.
The system is designed to cycle on, do its job, and shut off when the indoor air hits the set point. When it never shuts off, it is chasing a target it cannot hit. That gap between what the thermostat is asking for and what the equipment can deliver is the whole problem. Every cause below creates that same gap – just through a different failure path. Running continuously also runs up your energy bill and adds unnecessary wear to the compressor, which is the most expensive part of the system to replace.
Why It Happens
Clogged Air Filter
A heavily clogged filter blocks the airflow your system needs to move heat out of your home. Without enough air moving across the evaporator coil – the cold metal coil inside your air handler that absorbs heat from the air – the system just keeps running because warm air is never making contact with the coil efficiently. Pull the filter out and hold it up to a light. If you cannot see light through it, that filter is the first thing to address. A clogged filter can also cause the coil to ice over, which leads to the next problem.
Frozen Evaporator Coil
When airflow drops too low, or when refrigerant levels are off, the evaporator coil gets so cold that moisture in the air freezes solid on its surface. A coil buried in ice cannot absorb heat, so the system runs and runs and gets nowhere. You can often confirm this yourself: shut the system off, let it sit for an hour, and open the access panel on the air handler. If you see frost or a block of ice on the coil, that’s your answer. Do not run the system in cooling mode while the coil is frozen – you will strain the compressor. Switch the thermostat to fan-only to help it thaw, and call for service.
Low Refrigerant (a Leak)
Refrigerant is the substance that actually carries heat from inside your home to the outdoor unit. Your system does not consume refrigerant the way a car burns gas – it circulates in a sealed loop. If the level is low, there is a leak somewhere in that loop. A system short on refrigerant loses cooling capacity and runs constantly trying to compensate. Signs that point to this: the air coming from your vents feels less cold than it used to, or you see ice on the copper lines running to the outdoor unit. Refrigerant handling requires EPA certification and specialized equipment – this is a job for a technician, not a DIY fix.
Failing or Oversized Ductwork / Wrong System Size
If the system is undersized for the space it is cooling, it will run indefinitely because it physically cannot keep up with the heat load on a hot day. Leaky ductwork causes the same symptom: conditioned air escapes into attic or crawl space before it reaches the rooms it is supposed to cool. Check your supply registers – if some rooms are noticeably warmer than others with the system running hard, duct leakage or system sizing is worth investigating. A technician can measure supply and return airflow to confirm.
What to Do Right Now
- Check the air filter first. Find your filter – usually in the return air grille on a wall or ceiling, or in the air handler cabinet itself. If it is visibly clogged, replace it. This takes two minutes and costs almost nothing, and it occasionally solves the whole problem on the spot.
- Check the thermostat setting. Make sure it is set to “cool” and “auto” – not “on.” The “on” setting runs the fan continuously regardless of temperature, which can make it seem like the system never shuts off when the compressor actually is cycling.
- Look at the outdoor unit. Walk outside and look at the condenser – the large metal box with a fan on top. Make sure nothing is blocking airflow around it: overgrown shrubs, debris, or a lawn chair pressed against the side. Keep at least two feet of clearance on all sides.
- Check the indoor air handler for ice. If you suspect a frozen coil, switch the thermostat to fan-only and let the system thaw for 60 to 90 minutes before running cooling again. Do not chip at the ice – you risk puncturing the coil. Photograph what you see so the technician knows what they are walking into.
- If you smell burning or hear grinding or hissing, shut the system off at the thermostat and call immediately. A hissing sound near refrigerant lines is a refrigerant leak. Burning smells near the air handler can indicate an electrical problem. Neither of those is a situation to let run.
How We Fix It
When your local Dalton Heating & Air technician arrives, the first thing they do is a systematic diagnosis – not a guess. They will check static pressure, supply and return airflow, refrigerant charge using gauges connected directly to the system, and the condition of the evaporator and condenser coils. That process typically takes 30 to 45 minutes and produces a clear answer, not a shortlist of possibilities.
Once the cause is confirmed, you get a written price before any work starts. That is not something we offer as an upgrade – it is how every Dalton job runs, under The Garrison Standard. If the repair is a refrigerant recharge and leak repair, that falls under our AC Repair service. If the diagnosis points to a system that is too old or too far gone to repair economically, we will tell you that plainly and discuss your options, including heat pump installation if that makes sense for your home. Most single-cause repairs are completed the same visit. The repair is covered by a written guarantee for a full year, and if it fails in that time, we come back at no charge.
Frequently Asked Questions
It can cause real damage and should not wait. A system running non-stop puts continuous stress on the compressor – the heart of the outdoor unit and the most expensive component to replace. If the root cause is a frozen coil or low refrigerant, running through it accelerates that damage. Call (361) 306-9515 today so we can get someone out before a manageable repair becomes a much larger one.
Your local Dalton Heating & Air team takes calls around the clock – a live person answers at (361) 306-9515 every hour of every day, including weekends. Availability depends on your location and current schedule, but our team will tell you exactly when they can be there and will arrive inside the window they give you – that is part of The Garrison Code, not a talking point. Call now to find out the earliest opening.
Most cases of continuous running are fixable without replacing the system – a dirty filter, frozen coil, or refrigerant leak are all repair-level problems. If the system is old and the repair cost approaches what a replacement would cost, a Dalton technician will tell you that directly and explain both paths. You will always get that information in writing before any decision is made.
We do not publish flat-rate prices for this symptom because the cause determines the cost – a filter swap is very different from a refrigerant leak repair. What we can tell you is that your written price will be in front of you before a single tool touches your system. No number moves at the door. Call (361) 306-9515 and we will schedule the diagnostic visit and get you that written estimate on-site.
Get It Fixed
Call (361) 306-9515 right now – a real person answers every call, every hour. Your local Dalton Heating & Air team will confirm your appointment window, arrive on time, and put the repair price in writing before any work starts. The 365-Day Done Right Promise covers every repair we make.
Written by Marco Benitez, Owner and Lead HVAC Technician, Dalton Heating & Air – a Garrison Partners company in service since 2003.
What Our Customers Say
"Good communication, tidy, and disciplined work. Taped off the floor and wiped the unit down."
- Karen J."Installed a heat pump to replace an old oil furnace. Three clear quotes and the install crew was tidy."
- Cheryl B."Tech arrived in uniform right on time. AC wasn't cooling, found a failed capacitor, and replaced it in twenty minutes. The owner is a veteran and the company runs like it."
- Frank O.