Marvair MAA/MGA Wall Mount AC Installation & Operation Manual
05/2023 Rev.21
55
Failure to follow safety warnings exactly could result in serious injury, death, and/or
property damage.
Turn off electrical power at fuse box or service panel BEFORE making any electrical
connections and ensure a proper ground connection is made before connecting line
voltage.
Heater installation (see drawings and wiring diagram)
1. Remove top front panel.
2. Remove bottom front panel.
3. Remove the control box cover.
4. Remove the heater access cover plate on the upper right side of the unit by removing
the three screws. Cut insulation on two sides and fold down out of way.
5. Slide new heater assembly into place by lining up stem with hole on far end. Make sure
stem of new heater assembly is inserted into correct hole. The hole nearest to the indoor coil
is for three element heaters and the farthest away from indoor coil is for all other heaters.
6. Install the two No. 10 screws in the heater assembly plate.
7. Install wire harness in hole provided in drain pan and then through filter bracket and then
into control box.
8. Wire the heater as shown in the wiring diagram provided with the heater kit (the insulated
terminal ends are to be connected at the heater)
9. Install pop tie in appropriate hole in back panel to secure wire.
10. Install closed cell strip around wires where they pass through the drain pan.
11. Reinstall the heater access cover.
12. Mount the heat contactor inside the control box where the mounting holes are provided for
the heat contactor.
13. Make the wiring connections inside the control box as shown in the wiring diagram
provided with the heater kit. Bundle loose wires with wire ties.
14. With a permanent marker, place an (X) in the space provided next to the heater kit rating
of the installed heater on the unit data label.
15. Place the wiring diagram provided with the heater kit inside the zip lock bag which is
affixed to the back side of the control box cover.
16. Replace the control box cover, the bottom front cover and the top front panel.
