Nordyne 661021R Orifice 322838-752 and 3ARR3MARS65 units often found

and 3ARR3MARS65 units often found in high-performance HVACR systems

This heater is strictly for 480V high-voltage systems and will not function correctly on 208/230V or 575V equipment

Precise Control: The SPDT switch configuration allows for flexible wiring options to manage auxiliary heat kits or staging

always verify orifice sizing and spring pressure adjustments during the conversion process

System Safety Integrity: Vital for detecting venting obstructions or failed inducer motors to prevent hazardous operation

Nordyne 661021R Orifice 322838-752 and 3ARR3MARS65 units often foundThe Nordyne 661021R Orifice is a precision engineered Natural Gas Main Burner Orifice designed to maintain exact fuel to air ratios in residential heating systems. Featuring a #21 drill size (nominal . 021 diameter), this OEM component is a direct replacement for the Nortek 661021, ensuring calibrated gas flow for the MG1E 077 gas furnace and compatible mobile home heating units. For a technician in the field, using a correctly sized burner orifice is