2026 Rivian R1T Problems: 2 Known Issues

On the 2025-2026 Rivian R1T, this is a Gen 2 specific issue and does not apply to Gen 1 trucks. For model year 2025-2026 Rivian replaced the Gen 1 (2022-2024) PTC resistive cabin heater with a heat pump, which is far more efficient in cold weather but mechanically far more complex — it runs the refrigerant circuit in reverse to pull heat from ambient air. Gen 2 owners report an unusually loud compressor (commonly described as a jet engine or lawnmower noise from the front of the vehicle when heat or A/C is active), followed in a meaningful number of cases by a 'Thermal system fault' message and complete loss of cabin heat. Some failures are refrigerant loss from a leaking heat pump / AC compressor, which drains the circuit and takes cabin cooling down with the heat. Others present as slow warm-up: owners directly comparing a 2025 to a 2024 report the Gen 1 truck heating almost immediately while the Gen 2 takes five-plus minutes and never fully warms the footwells. Loss of heat also means loss of windshield defrost, which is a genuine safety problem in freezing or wet conditions. There is no NHTSA recall for this — it is a warranty pattern, not a campaign. Separately, Gen 1 trucks have their own HVAC problem addressed by service bulletins RCA-26-24-002-1 and RSB-26-26-001-1, covering a faulty front HVAC case drain that leaks water into the front footwells.

On the 2025-2026 Rivian R1T, improperly manufactured front turn signal lamps (the lower fascia direction indicator lamps) on Gen 2 R1T and R1S vehicles can leave one or both front turn signals dead — the signal fails to illuminate and flash at all. Because the front turn signal is a required exterior lighting function, the condition is a non-compliance with FMVSS 108 (Lamps, Reflective Devices and Associated Equipment) rather than a wear item, and surrounding drivers get no indication of an intended lane change or turn. Rivian first filed this as NHTSA campaign 25V-387 in June 2025. The supplier failed to fully contain the bad parts, so Rivian later expanded the population as NHTSA campaign 26V-508 (Rivian FSAM-1833), adding 625 model year 2025-2026 R1T trucks built October 1, 2024 through March 19, 2026 alongside 3,204 R1S units. The expansion adds trucks that were not in the original 25V-387 population, so a VIN that was clear of the first campaign may still be covered by the second.