I got another error this morning.
The two fans came on, when the heat should have come on.. (Both fans use the same device code, 7)
In binary, the fan device is 0111 and the heat device is 0101 ..
Seems like a burst of RF noise or AC line noise in the middle of the byte, could confuse the receiver.. A single bad bit..
I would change the house code on the fans, but that would make them too hard to control them using the handheld RF remote control.
Maybe I just need to make the device bytes more dissimilar.
My three device codes in use now, are 5, 6 & 7. 0101, 0110 & 0111.
I'll change them to 0001, 1000 & 1111 and see if that makes them noise proof..
If those device codes still get errors, I'll try using three different house codes too.
FAN_ON:
X10 2 7 1
RET
HEAT_ON:
X10 2 5 1
RET
etc.