Lockouts On Modulating Furnaces

Lockouts On Modulating Furnaces

by HVAC Distributors

Goodman recently released Service Bulletin SF-067 regarding lockouts on 40″ modulating furnaces.

From Goodman:

Nuisance or unexplained lockouts (E0 Lockout Code Displayed on 7-Segment Display) with the 40” modulating furnaces may be due to moisture in the front cover pressure switch tube, which causes the pressure switch to open.

If you experience this condition with 40” tall modulating furnace models *MVM96 & DM96MC (upflow application only), the front cover pressure switch should be disconnected (see instructions below). The furnace still has the Induced Draft Blower Low Pressure Switch, which can shut the furnace down in the event of a blocked drain.

MVM96 & DM96MC furnace warning

To service: Disconnnect electrical power, then remove the wires from the front cover pressure switch and cut the spade terminal from the wires. Strip the end of the wires and wire nut the wires together.

MVM96 & DM96MC wiring diagram

Click here for the wiring diagram is in reference to Service Bulletin SF-067.
Print this wiring diagram and leave it with furnace.

If you have questions about this bulletin, HVAC Distributors customers can reach out to our Technical Service department at 800.228.4822 x5.