2021 Thor Motor Coach Magnitude problems: recalls, complaints and what to check
NHTSA has 2 recalls and 3 owner complaints on file for the 2021 Thor Motor Coach Magnitude. Here is what they are, what a technician checks for each kind of fault, and how to look one over before you buy it.
LP gas and gas appliances: 2 recalls
Recall 21V754000 (28/09/2021): EQUIPMENT:RECREATIONAL VEHICLE/TRAILER:LPG SYSTEMS:LINES AND FITTINGS
Thor Motor Coach (TMC) is recalling 2021-2022 Magnitude and Omni motorhomes. The LP gas line may have been incorrectly routed through the rear suspension leaf springs, which could damage the line and cause a gas leak.
Fix: Dealers will re-route the LP line as necessary, free of charge. Owner notification letters were mailed November 23, 2021. Owners may contact TMC customer service at 1-877-855-2867. TMC's number for this recall is RC000242.
Recall 22V094000 (18/02/2022): EQUIPMENT:RECREATIONAL VEHICLE/TRAILER:LPG SYSTEMS:LINES AND FITTINGS
Thor Motor Coach (TMC) is recalling certain 2020-2021 Omni and Magnitude motorhomes. The LP gas line may have been incorrectly routed through the rear suspension leaf springs, which could damage the line and cause a gas leak.
Fix: Dealers will re-route the LP line as needed, free of charge. Owner notification letters were mailed March 24, 2022. Owners may contact TMC customer service at 1-877-798-855-2867. TMC's number for this recall is RC000256. This recall is an expansion of NHTSA recall 21V-754.
What a tech checks: Regulator, lines and fittings, then the appliances: furnace, water heater, range. A proper pressure-drop leak test is the first thing a tech does on an LP complaint. Before you buy: Smell for gas with the tank open; have a shop do the leak test.
LP and furnace lessons · Furnace guide · Furnace 3D lab · Water heater 3D lab
12 volt and 120 volt electrical: 2 complaints
What a tech checks: Voltage drop, grounds, the converter and the transfer switch. Melted shore-cord plugs and bad grounds cause most of the electrical complaints techs actually see. Before you buy: Battery at rest, converter output on shore power, GFCI test, every outlet.
12 V electrical lessons · 120 V and generator lessons · Wiring diagrams
Structure, roof and leaks: 1 complaint
What a tech checks: Roof sealant, seams, window and slide seals, and the frame. Water intrusion shows up as delamination, soft floors and stained ceilings months after the leak started. Before you buy: Press the sidewalls and walk the floor; look at every seam and seal.
Roof, leaks and body lessons · Seals and leaks guide
Other: 1 complaint
Motorhome chassis: 1 complaint
What a tech checks: The chassis (Ford, Freightliner, Mercedes, Ram) is serviced by the chassis maker's dealer, not the RV shop. RV techs handle the house, not the drivetrain. Before you buy: Chassis recalls are fixed free at the chassis maker's dealer.
What owners reported to NHTSA
12/18/2020, POWER TRAIN: TL* THE CONTACT OWNS A 2021 THOR MAGNITUDE BB35 BUILT ON A 2020 FORD F-550 CHASSIS N/A. THE CONTACT STATED WHILE STATIONARY AT A TRAFFIC LIGHT, WHILE THE DEPRESSING THE ACCELERATOR PEDAL, THE RV MADE AN ABNORMAL NOISE AND STARTED TO ROLL BACKWARDS. THE CONTACT STATED NO WARNING LIGHT WAS ILLUMINATED. THE CONTACT STOPPED THE RV BY DEPRESSING THE BRAKE PEDAL. WHILE SHIFTING TO PARK, THE RV CONTINUED TO ROLL BACKWARDS.
09/23/2025, ELECTRICAL SYSTEM,STRUCTURE,UNKNOWN OR OTHER: Rear house battery tray weld failed, tray fell and hit the ground, damaging BIM, various cables etc. Identical to Recall 19V-566 (2019–2020) but not included for 2021. Safety concern: Batteries may detach on roadway, cause shorts/fire, or total power loss.
06/15/2023, ELECTRICAL SYSTEM: A wiring harness was found pinched, pins bent and broken, apparently in the process of mating the motorhome body to the cassis cab. This cable has power in it and could result in a vehicle fire. Thor has been completely unresponsive in assisting me, despite acknowledging it’s out of warranty, and I simply needed verification of their integration to the chassis, to reassure the after market warranty that this wasn’t s
Looking at a 2021 Thor Motor Coach Magnitude?
The Buyer's Check walks you through it on your phone: what to ask, the outside walk-around, water damage, every system on every power source, with the recalls above built in. You get a report that says what's a walk-away and what to negotiate on.
Checked against NHTSA 2026-10-23. Recall repairs are free at an authorized dealer. Complaints are owner reports to NHTSA and are not verified.