[RFI] Whirlpool Gas Range RFI Solution

[Ward Silver]

This is a post to get a specific solution into the archives.

73, Ward N0AX

Whirlpool Gas Range, model SF385PEE

Symptom: Transmitting with 25 or more watts to nearby low dipole (20-30' directly over range) at or below 10 MHz causes oven door latch solenoid to activate.  Latch is released when transmitting stops, but eventually the controller displays an error code and no longer responds.  Error code clears on pressing OFF and normal operation resumes.

Unsuccessful fixes included
1. Corcom ac line filter
2. Several turns of ac line cord on Radioshack ferrite split-core in addition to 1
3. Radioshack ferrite snap-on core on cable bundle to controller P3 (switch and sensor I/O)
4. Radioshack ferrite snap-on core on cable bundle to controller P4 (ac input)

Successful fix (both required)
A. 0.0068 uF ceramic capacitor from ac hot and ac neutral to nearby controller chassis mounting screw - capacitors must be ac line rated
B. 0.0068 uF ceramic capacitor across all three I/O circuits of P3; oven temp sensor, door switch input, door latch output

Fix was verified by removing bypass capacitors from either P3 or P4 and symptoms returned.  All unsuccessful fixes except 4 were removed.  4 was left on "for good measure".

Capacitors were attached by inserting their wire leads into the plastic sockets of P3 and P4 for friction fit.  Capacitors for A will be re-installed with insulated "tee" connector in wiring harness after the proper parts are obtained.

Keywords: Whirlpool, gas range, SF385PEE, oven door latch, RFI, solution, cure, fix, error code