AC Compressor Not Turning On? The Step-by-Step Ladder for Split ACs in India
What Daikin, Samsung, Panasonic, LG and Voltas publish about an outdoor unit that will not start: the normal delay, voltage limits, error codes, the power-cycle steps Daikin and Samsung publish, and who pays if it is the compressor.
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Panasonic 1.5 Ton 3 StarPremium Wi-Fi inverter smart split AC₹37,000Amazon, 8 Nov 2026★ 3.9Check price ↗
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Carrier 1 Ton 3 StarFlexicool inverter split AC, copper₹32,000Amazon, 8 Nov 2026★ 4.2Check price ↗The short answer. Two makers publish a restart delay of about 3 minutes. Daikin’s FAQ says the air conditioner “does not operate for three minutes” when switched on right after shutdown or after a mode change. Samsung, for power cuts: “the indoor unit will operate for 3 minutes first, and later the compressor will operate …”. If that time has passed and the outdoor unit is still silent, work down our ladder below: power, voltage, the signal between the two units, then the error code. Past those checks, Daikin’s manual says “Do not attempt to repair or modify the air conditioner by yourself.”
If the compressor does run but the room stays warm, that is a different problem, covered in our AC not cooling guide.
Why an AC compressor is not turning on: the ladder
The order is ours, built from causes the makers publish; no maker page we read publishes this ladder as a diagnosis. Each step says whose document it comes from, and each maker’s instruction applies to its own units.
Step 1: Wait about 3 minutes
Daikin’s manual (MTKM50XV16, read 30 September 2026) lists this under “These cases are not problems”: “Operation does not start soon. • This is to protect the air conditioner. You should wait for about 3 minutes.” After a power failure: “The air conditioner automatically resumes operation in about 3 minutes.”
Samsung India (stabiliser article, updated 6 October 2025) says that after a power outage “the compressor will operate after approximately 3 minutes”.
Step 2: Daikin’s checks before calling service
Daikin’s troubleshooting page, under “The air conditioner does not operate. (The operation lamp is off.)”, lists: “Is the breaker thrown or the fuse blown? · Is the power plug connected to the outlet? · Has there been a power failure? · Do the batteries in the remote controller need replacement? · Is the timer set correctly?”
Step 3: Check the voltage
Daikin’s manual, under “These cases are not problems”: “Operation stopped suddenly. (OPERATION lamp is on) • To protect the system, the air conditioner may stop operating after sudden large voltage fluctuations. It automatically resumes operation in about 3 minutes. Voltage range protection: 130V-285V”.
Voltas’s low-voltage blog (8 October 2025): “If the supply falls short, the compressor struggles or stalls”.
The ranges each maker publishes:
| Maker | Published figure | Where | What it says about a stabiliser |
|---|---|---|---|
| Daikin (MTKM, MTKL, JTKJ, FTKF series) | 130-285 V | Spec pages, manual | Spec pages: “Stabilizer Inside ✔”. Manual: “Use a stabiliser if required by the voltage supply condition” |
| Panasonic splits (EU18, SU18, HU18) | 100-290 V | Spec pages | SU18, HU18 pages: “stabilizer free operation with a well-defined voltage range … If power fluctuations are beyond the defined voltage range, a stabilizer is required.” |
| LG (AS-Q20ENZE) | “120V~290V” | LG product page | “Stabilizer Free operation = Yes” on six LG product pages |
| Voltas (inverter ACs in general) | “usually between 140V and 290V” | Voltas blog, 9 July 2026, on inverter ACs in general, not a Voltas model spec | “If voltage levels drop below or rise above this range, the AC may shut down or experience stress.” |
| Onida inverter range | 140-290 V | Onida blog, read 13 September 2026 | Works without a stabiliser in that range; “For older ACs, a voltage stabiliser is recommended.” |
| Samsung | Indoor fan motor protection: “overload voltage protection (OVP)” activates “above approximately 290-310V” (code C154) | Samsung error-code article and “Is voltage stabilizer required for an AC” article, both 3 February 2026 | S-UTR compressor models: “no requirement of an extra voltage stabilizer”; without S-UTR, “an external stabalizer [sic] is required to ensure long life of the product” |
Samsung ties this threshold to the indoor fan motor, not the compressor. An intermittent C154 clears on its own: “Once the voltage stabilizes below 290V, the unit can operate normally again.” A C154 that returns within 10 seconds of a restart indicates, in Samsung’s words, a “defective fan motor or PBA”.
The warranty range is narrower than the spec sheet. Daikin’s warranty: “The Product is designed to operate at voltage supply of 230 Volts plus or minus 10% in case of single phase Product … Any failure due to operation of the Product outside the voltage limits will not be covered under this warranty.” Panasonic’s standard warranty: “The Product is defined to operate at a voltage supply of 230 Volts ±10% & Frequency 50±3 Hz in case of single phase product.”
230 V ±10% works out to 207-253 V (our arithmetic). That is narrower than the 130-285 V on Daikin’s spec pages and the 100-290 V on Panasonic’s. How inverter and fixed-speed units differ more widely is in our inverter vs non-inverter AC comparison.
Step 4: The signal between indoor and outdoor unit
- Daikin: code U4, “FAILURE OF TRANSMISSION (BETWEEN INDOOR UNIT AND OUTDOOR UNIT)”.
- Samsung: codes C 101 and C 102, “Communication Error between Indoor and outdoor unit.” Samsung’s Smart Install guide (3 January 2025) adds, for C 102, “Refrigerant not flowing into the indoor unit … Check and ensure the outdoor unit compressor is operating.” Its fix, “Check the cables connection between the indoor and outdoor units”, sits in an installation guide.
Step 5: A compressor start fault, and Daikin’s related codes
Daikin’s code E6 reads “FAULTY COMPRESSOR START UP”. It is the only published code we found that names a compressor start failure, and it is Daikin’s alone. Daikin’s related codes below are verbatim from its error-code page and the MTKM50XV16 manual (U4 is in Step 4, U0 in Step 6). Daikin files the E, F and L codes under the heading “OUTDOOR UNIT”; F8 appears in the manual, not on the error-code page.
| Code | Daikin’s wording |
|---|---|
| U2 | DROP VOLTAGE OR MAIN CIRCUIT OVERVOLTAGE |
| E1 | CIRCUIT BOARD FAULT |
| E5 | OL STARTED |
| E6 | FAULTY COMPRESSOR START UP |
| E7 | DC FAN MOTOR FAULT |
| E8 | OVERCURRENT INPUT |
| F3 | HIGH TEMPERATURE DISCHARGE PIPE CONTROL |
| F6 | HIGH PRESSURE CONTROL (IN COOLING) |
| F8 | OPERATION HALT DUE TO COMPRESSOR INTERNAL TEMPERATURE ABNORMALITY |
| L3 / L4 / L5 | ELECTRICAL PARTS HEAT FAULT / HIGH TEMPERATURE AT INVERTER CIRCUIT HEATSINK / OUTPUT OVERCURRENT |
We give Daikin’s wording only; Daikin does not explain these codes further on the pages we read.
Step 6: Refrigerant shortage or blocked flow
- Daikin: U0, “REFRIGERANT SHORTAGE”.
- Samsung (Smart Install guide, installer codes): code C 554, “Lack of Refrigerant. (For Inverter model only)”, and code C 422, “Refrigerant flow blocking error”. Both carry “Check for refrigerant leaks”.
- Samsung (decode article, 10 February 2026): “EC error code appears if a gas leakage is detected or the sensor is not functioning.”
If a refrigerant code appears, see our AC gas leakage guide.
Step 7: Blocked airflow or a dirty filter
Daikin’s manual lists a separate case: “Operation stops suddenly. (OPERATION lamp is blinking) • Are the air filters dirty? … • Is there anything blocking the air inlet or air outlet of the indoor unit or outdoor unit?” Note the lamp: in Step 3 Daikin’s voltage stop is described with the lamp on, this one with it blinking.
The Samsung “CH” trap. On a Samsung AC, “CH” is not a fault. Samsung describes it as a filter reminder, “every 336 hours”. Samsung’s “CF” is also a filter reminder. We could not verify what “CH” means on other brands.
How to read the error code
Daikin: its error-code page and manual describe a fault-diagnosis mode on the remote: hold CANCEL for about 5 seconds until “00” blinks, then press CANCEL repeatedly, as the code shown changes, until you hear a long beep. Daikin’s FAQ: “The display indicates the type of error. Check the alphanumeric characters and notify your dealer when requesting a repair.”
Samsung: codes are published across its support articles, quoted above.
LG, Voltas, Panasonic and Blue Star: error-code meanings were not in anything we could read. For these brands, use your own manual or the brand’s helpline; LG publishes a national helpline (08069379999) and WhatsApp (9711709999).
Resets: what Daikin and Samsung publish
Daikin’s FAQ gives a power cycle for a specific symptom, “The air conditioner operates abnormally.”, which it says lightning and radio waves can cause: “Cut off the power supply by unplugging the power cord or turning off the circuit breaker, then re-supply power and restart”. Samsung gives a main-power switch-off for its EC code: “switch off the AC from the main power supply and then turn it ON. If the error disappears, there might have been a sensor issue.” Samsung also uses a restart to tell a passing C154 from a fault (Step 3). Neither maker, on the pages we read, presents these as a compressor reset.
“Forcing” a compressor on or testing it yourself is not published as a user procedure on any manufacturer page we read. Daikin’s warranty says it is void “if the failure of the compressor is due to lack of proper preventive maintenance of the Product by the Purchaser or if the Product is repaired or attended by an unauthorized person.” Onida’s blog lists a compressor that is not starting or tripping as a technician job: “anything involving refrigerant, the compressor, or electrical components is not a DIY task.”
What it costs if it is the compressor
Within each maker’s compressor warranty, the part itself is covered; the other costs, in each maker’s words:
| Maker | Compressor cover | What the owner pays |
|---|---|---|
| Daikin | Inverter split: 1 + 9 years (purchases on or after 1 Sept 2019). Non-inverter: 1 + 4 years | Additional warranty “shall not cover gas charging, related labour and transportation charges” |
| Voltas | 9 years additional (inverter), 4 years (fixed speed), after year 1 | “Gas, Labour, Transportation or any other parts shall be borne by the purchaser” |
| LG | 10 years, “Applicable only on Inverter Compressor” | Purchases from 1 Aug 2024: “both gas and labor amount to be paid by customer” |
| Panasonic | Standard: 5 years (rotary compressor). Promotional 1+9 on selected inverter models, “Part Only”, scheme to 31 March 2027 | “Cost of labor, transportation and other incidental expenditures shall be borne by the Customer after the lapse of first year” |
Published rate cards (taxes extra):
- LG, effective 17 February 2026: inverter AC repair ₹600 carry-in, ₹750 in-home, ₹600 transport; inverter AC gas charging ₹2,750, plus ₹600 transport. LG: “No service charges applicable if complaint repeats within 3 months from date of service invoice”.
- Samsung, page as read 30 September 2026 (no effective date on the page we read): split AC repair ₹600, inspection ₹300; inverter split gas charges ₹2,750.
Daikin’s out-of-warranty repair and gas charges are not on the pages we read. Panasonic’s chart is an image we could not obtain.
What we could not verify
- Error-code meanings for LG, Voltas, Panasonic and Blue Star.
- A user method to force or test a compressor.
- Samsung’s compressor-tripping and power-check articles: video or image only, no text we could read.
- Daikin’s repair and gas charges, and Panasonic’s out-of-warranty chart.
FAQ
What is the 3 minute rule for AC?
None of the manufacturer pages we searched uses the phrase. What Daikin and Samsung publish is a restart delay: Daikin’s AC “does not operate for three minutes” when switched on right after shutdown or after a mode change, and resumes “in about 3 minutes” after a power failure. Samsung says that after a power cut, the indoor unit runs for 3 minutes first, then the compressor starts.
Why is my AC fan running but the compressor isn’t working?
Samsung describes exactly this after a power cut: the indoor unit runs first and the compressor starts about 3 minutes later. If it persists, these are the published codes and cases we map to it (the mapping is ours, not a maker’s): Daikin U2 (“DROP VOLTAGE OR MAIN CIRCUIT OVERVOLTAGE”), Daikin U4 and Samsung C 101/C 102 (indoor-outdoor communication), Daikin E6 (“FAULTY COMPRESSOR START UP”), Daikin U0 and Samsung C 554 (refrigerant), and Daikin’s sudden stop with the lamp blinking (dirty filters, blocked airflow).
How do I reset an AC compressor?
No maker we read publishes a compressor reset. Daikin’s power cycle is for when the air conditioner “operates abnormally”: cut power at the plug or circuit breaker, restore it and restart (Daikin’s 3-minute restart delay applies). Samsung publishes a main-power switch-off for its EC code.
