You paid for an AC service, the technician spent 45 minutes at your home — and your AC still isn't cooling properly. This is one of the most common complaints we hear from customers across Delhi, Gurgaon, Noida and Faridabad, especially in the peak summer months when every technician is rushing through 8–10 jobs a day.
Here are the 7 most common reasons your AC fails to cool after a service, what to check yourself, and what to demand from the technician before they close the job.
The most common reason. A standard "service" typically includes cleaning — it does not automatically include checking or refilling refrigerant gas. If your AC has slow refrigerant loss (micro-leak), the gas pressure may have dropped to a level where the system can't achieve proper cooling, even after cleaning.
Fix: Ask the technician to attach a manifold gauge to the service port and show you the pressure reading. For R-22 gas, low side should be 65–70 PSI at ambient. For R-32/R-410A, it's higher. If it's low, you need a gas top-up: ₹1,200–₹2,500.
Many low-cost "service" visits only clean the indoor unit — rinsing the filter and wiping the face. But the outdoor condenser unit collects an equal or greater amount of debris. In Delhi's summers, cottonwood fluff, dust and pollution clog the condenser fins within a few months, drastically reducing heat rejection and cooling capacity.
Fix: Insist on condenser coil cleaning as part of every service. The technician should rinse the outdoor unit fins with a jet of water from inside-out. If this wasn't done, request a follow-up outdoor unit clean.
After years of use, the evaporator coil builds up a biofilm layer — a mixture of dust, mold, and organic matter — that water alone won't remove. A chemical coil cleaner (alkaline foam spray) is required to break down this layer and restore proper heat transfer. Budget technicians often skip this step to save time.
Fix: A proper "jet wash" or "deep clean" service includes chemical coil treatment. If your AC still smells musty after a service, or the coil visibly has dark residue, you need a chemical clean (₹700–₹1,200 extra).
If your AC loses gas, simply topping up the gas without fixing the leak means you'll have the same problem in 4–6 weeks. Common leak points include flare nut joints, the indoor unit service valve, and corroded copper pipe. Detecting leaks requires electronic leak detector or soapy water test — steps many technicians skip.
Fix: Ask the technician to perform a leak test after gas top-up. If gas pressure drops significantly within a month of top-up, there's an active leak — insist on a leak detection and repair (₹500–₹1,500 depending on location).
The indoor unit blower (squirrel cage fan) accumulates a thick layer of black dust over years. Even with a clean filter, a clogged blower moves less air — reducing cooling output significantly. A blower cleaning requires partial disassembly of the indoor unit and is often skipped in quick service visits.
Fix: If your AC's airflow seems weak even with clean filters, request a blower cleaning specifically. The technician should access the blower wheel and clean each fin. Adds 30–40 minutes to the service time.
A weak or failing capacitor causes the compressor or condenser fan motor to run slowly or intermittently. The AC appears to be "on" and the indoor unit blows air — but without the condenser running at full speed, cooling is poor. This is easy to miss if the technician doesn't check outdoor unit operation during the service test run.
Fix: Ask the technician to observe the outdoor unit during the test run — the condenser fan should spin freely and the compressor should be running (you'll hear a steady hum). If the fan is slow or the compressor is cycling erratically, a capacitor test is needed (₹200 test, ₹600–₹1,000 for replacement).
This isn't the technician's fault, but it's commonly misdiagnosed as an AC problem. If your 1-ton AC is trying to cool a 200 sq ft room with west-facing windows, no ceiling insulation, and 3 people plus electronics generating heat — no amount of servicing will make it feel cold enough on a 45°C Delhi afternoon.
Fix: Check if your AC unit is correctly sized for the room. As a rough guide: 0.8 tons per 100 sq ft in normal Delhi conditions, 1 ton per 100 sq ft in west-facing or poorly insulated rooms. Also ensure windows and doors are closed, and direct sunlight is blocked with curtains.
Temperature delta test: Hold a thermometer at the indoor unit return air grille (inlet), then hold it at the outlet. The difference should be 8–12°C. A delta of less than 6°C means either insufficient gas, dirty coil, or compressor weakness — all fixable problems.
If after reading this guide you believe the original service was incomplete, contact the service provider and request a free recall visit within 30 days of service. Any reputable AC service company in Delhi should honour a recall if the problem was not resolved.
Air Control provides a 30-day workmanship warranty on all services. If your AC isn't cooling after our visit, we come back — at no charge.
The most common reasons are: low refrigerant gas not topped up, outdoor condenser not cleaned, dirty evaporator coil not chemically treated, or a refrigerant leak not identified. A standard service often only cleans the filter — which is insufficient for poor cooling.
A properly serviced AC should cool noticeably better within 15–20 minutes. If after 30 minutes the room temperature isn't dropping, the service likely missed something — most commonly low gas or a dirty condenser coil.
A standard service does not include gas top-up. Refrigerant refill is a separate service charged ₹1,200–₹2,500. If your AC has low gas, request a gas charge in addition to servicing.
Filter cleaning, evaporator coil chemical cleaning, blower cleaning, drain tray flushing, condenser coil cleaning, refrigerant pressure check, electrical connections check, and a test run with temperature delta measurement.
Book a follow-up and ask for: (1) gas pressure reading with manifold gauge, (2) condenser coil cleaning, (3) temperature difference test. If the tech did all these and cooling is still poor, the compressor may be weak and need evaluation.