Tesla Model 3/Y heat pump not heating: 2021 recall and fixes

Symptoms

• No heat in frost, HVAC errors. On early batches, increased component wear when the coolant ran low.
• Specific error codes from the RTC chat: VCFRONT_a447 (t.me/teslacar_chat/76565), error 466 (t.me/teslacar_chat/277341).
• There are two separate failure mechanisms. The early one (January 2022): the air intake flap freezes, cold air bypasses the PT sensor and the compressor stops (t.me/teslacar_chat/77055; this explanation comes from Tesla staff, not an official document). The official mechanism behind recall 22V-050 is a software fault in the EXV valve: refrigerant gets trapped in the evaporator and the compressor goes into a protective shutdown. It is fixed by OTA update 2021.44.30.7 or later.
• A broken compressor "volute" is a separate mechanical failure that sends metal shavings through the loop: "after that, the 2 cabin radiators and the coolant radiator have to be replaced too" (t.me/teslacar_chat/475933). This is the extreme case.

What was done

• Software updates (closing "stuck" valve positions).
• Service bulletins for replacing the three PT sensors of the heat pump.
• For mechanical damage, components get replaced: the supermanifold, the octovalve and so on.

The service "menu": three levels of repair (from RTC)

A service technician (t.me/teslacar_chat/355431) describes three levels:

1. Compressor only: 3-4 hours of work, if the shavings have not spread further.
2. Compressor plus a supermanifold flush: 1 day, if shavings and oil have already partly spread through the loop.
3. Full system replacement: 2-3 days, if the volute is damaged and shavings are scattered everywhere.

Tesla part numbers for the key parts (t.me/teslacar_chat/478209):

• Compressor: 1501256-01-M
• Supermanifold (assembly): 1625000-A1-B

Cost (Minsk shop prices)

• A simple refrigerant top-up (if the level dropped and the loop is intact): minimal cost.
• Compressor replacement (a new one from a 2023-2024 car, used is also an option): ≈ $800–1 500 (your old one can be sold for $500-600).
• Compressor replacement plus supermanifold flush: ≈ $1 500–2 200 (US Tesla service: $2 200, t.me/teslacar_chat/488301).
• Full loop replacement (supermanifold, 2 cabin radiators and the coolant radiator when shavings have spread): up to $3 500+.

Links

• NHTSA Recall report (heating/defrosting): https://static.nhtsa.gov/odi/rcl/2022/RCLRPT-22V050-5142.PDF
• Consumer Reports on the recall: https://www.consumerreports.org/cars/car-recalls-defects/tesla-recall-faulty-heat-pump-loss-of-heating-a5384954255/
• PT-sensor bulletin: https://static.nhtsa.gov/odi/tsbs/2022/MC-10226577-9999.pdf
• CleanTechnica on the early mechanism (frozen air intake flap, Jan 2022): https://cleantechnica.com/2022/01/14/frozen-front-flap-leads-to-cold-cabins-for-teslas-with-heat-pumps/

Community experience TESLA Belarus

Analysis of 400,000 messages from the TESLA owner's group BELARUS chat. Topic #1 by discussion volume.

Additional fixes from chat:

1. First check the refrigerant level: often the issue is solved by a simple top-up (e.g. near ЭлектроЭра in Minsk).
2. For Denso compressors: in the config you can lower the rpm from 11,000 to 8,000. Tesla itself fixed this in software in later firmware.
3. R1234yf refrigerant can be replaced with R134a: they are physically compatible, and R134a is much cheaper (3.5 kg of R1234 ≈ 110,000 RUB, 13.6 kg of R134a ≈ 15,000 RUB, t.me/teslacar_chat/147624). A full replacement with vacuuming is required. ⚠️ R134a boils at -26°C versus -30°C for R1234yf, so in very hard frost the heat pump's efficiency will drop (t.me/teslacar_chat/182232).
4. Worst case: compressor replacement. A new one from a 2023–2024 car costs $800–900, and you can sell your old one for $500–600.
5. Smell from the AC is a separate issue: replace cabin filters + ozonate the cabin.
6. After any opening of the cooling loop (octovalve, supermanifold, compressor), you must bleed the coolant and remove the air lock. Otherwise the CPU temperature will climb and the car will start throwing warnings.

Who reported the issue: Ilya, Егор, Егор Десятов, Dmitry Mel, spadar, Danilius

Who found the fix: firago, Vitali K, P M, fl, Uladzislau, Илья Воронцов

Discussion in Telegram: #147798, #385822, #378444, #109399

Additional sources:

• Tesla heat pump problem explained in NHTSA recall (Electrek): https://electrek.co/2022/02/09/tesla-heat-pump-problem-causing-loss-heat-explained-nhtsa-recall/
• RTC: repost of Tesla's official explanation (China recall of 26,047 cars built 2020-12-28 → 2022-01-15): https://t.me/teslacar_chat/103360
• RTC: the 3-tier repair menu from a service technician: https://t.me/teslacar_chat/355431
• RTC: Tesla part numbers for the compressor and supermanifold: https://t.me/teslacar_chat/478209
• RTC: scattered shavings → 2 cabin radiators + coolant radiator: https://t.me/teslacar_chat/475933
• RTC: R1234yf vs R134a, the physics and cold-weather efficiency: https://t.me/teslacar_chat/182232