Why Does the RV Holding Tank Heater Have a Separate Ground Wire and Not a 3 Prong Plug?
Updated 01/27/2026 | Published 01/02/2026
Question:
What is the point of the ground wire being seperate from the plug? Seems like it would be better to have a 3 prong plug on this?
asked by: Ben
Expert Reply:
Hello Ben,
Great question. The RV Holding Tank Heater # 372HTH-A uses a separate ground wire because it’s considered a permanently installed, under-RV heating device, not a portable appliance. RV electrical standards require these heaters to be directly bonded to the RV’s metal frame so they remain safely grounded even if the outlet loosens, corrodes, or loses its ground. A dedicated chassis ground also handles vibration and moisture better than a plug-based ground and ensures a breaker trips immediately if the heater ever faults, which is why this design is safer than a standard 3-prong plug.
What kind of camper are you installing this on, and what was your favorite adventure of 2025?
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Kate F.
1/27/2026
Hey Ben, how did things go grounding the RV holding tank heater to your camper’s frame? Your update could make it easier for others wiring the same type of heater.