So, were you able to fix the problem?i have the same error code on my wall ovens. When I turn on oven to pre heat it will start to heat, then shut off and error code 4d21 appears. Feature not available. If I re set breaker several times, it will come back on and work for that time. Next time I try to use oven(s), same thing occurs. Do you know the fix?

Thanks

I ended purchasing the tangential fan (not the convection fan visible on the back) but the one inside the oven that you can not see. I purchased the replacement fan from AppliancePartsPro…best price. Then I hired appliance repairman to replace the part because I do not like working with electricity since the oven is direct wired. So he shut circuit breaker in basement off, disconnected electrical wires below cabinet, pulled the oven out of wall, disconnected the top metal cover by unscrewing many screws and then replaced the old tangential fan (3 small wires plug in). The old fan was very grimy and sticky. Put it all back together and it's been working so far…about a week now. Part $88, labor $206 (ouch).