I installed a 50A50-241 with a universal replacement part 50A55-843. All the connections were easy enough to transfer till I got to a white wire in slot E21 on the original Mode. The replacement does not have a slot E21 and I am getting the following error message:
115 volt ac power reversed improper ground. Can anyone suggest what I need to fix this problem? Thanks

Did the replacement come with instructions? If so, did you follow them? It is not always enough to transfer the connections wire-for-wire from one part to the next, even if the two parts appear the same. Terminal location does not always indicate function.

Thank you for responding so quickly. I have no experience reading schematics. When I purchased the replacement part the counter person said to follow the numbering from one to the other. For example the old board had a wire in slot E18 so I took the wire from the old board and transferred it to E18 on the new board and thought I was doing well. Till I got to the final wire E21 and I wasn't able to locate the same numbered slot on the new board. Subsequently getting the 6 flashes and indicating that I had reversed the power or had improperly grounded it.

Trace the extra wire to the source and post back.

I installed a 50A50-241 with a universal replacement part 50A55-843. All the connections were easy enough to transfer till I got to a white wire in slot E21 on the original Mode. The replacement does not have a slot E21 and I am getting the following error message:
115 volt ac power reversed improper ground. Can anyone suggest what I need to fix this problem? Thanks

Where line 1 and line two connect to the board, try reversing these two wires and see if there is a difference, of if the code changes.

Also did you disconnect a wire from the old board that is connected to the houseing of the furnace. If you did and that wire is still connected to the furnace there is probably a place that it should be connected to the new board.

I hope this helps.

All these are great suggestions. I will try again tomorrow. If I don't get it to work I will revert to calling a repair person and keep an eye on them and will report back for anyone dealing with this issue. Thanks you for your help

Thank you for responding so quickly. I have no experience reading schematics. When I purchased the replacement part the counter person said to follow the numbering from one to the other.

Rule #1 in this field... NEVER LISTEN TO THE GUYS BEHIND THE COUNTER! There is a reason that they are working in a supply house and not in the field. I learned this lesson the hard way.

If you are not handy with electrical work then you shouldn't have tackled this project in the first place.

See your other post on this subject

Or here


Here is a touble shoot procedure.

http://www.white-rodgers.com/wrdhom/...pg0259_264.pdf (http://www.white-rodgers.com/wrdhom/pdfs/06_Cat_pages/Cat_06_pg0259_264.pdf)

Pay attention to this note on page 1




A. Check continuity for C terminal on module to electrical service ground and
connection at the furnace junction box. If ground connection is open, check
module ground connection and the electrical service ground connection.
Repair and retest.
B. Re-connect electric power to system.
C. Check for voltage between the line neutral terminal and furnace ground. If
voltage exists, the main power supply lines are improperly connected to the
furnace (REVERSED POLARITY). Again disconnect electric power to system;
then reverse incoming supply leads to furnace. Repeat step.
D. Recheck system for proper operation.

See LINE and LINE N on page 4 here. Those are the leeds reversed. See below for this


http://www.white-rodgers.com/wrdhom/.../0037-6265.pdf (http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-6265.pdf)
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