There have been no fault codes listed on this thread. All the numbers everyone has listed are boot up sequence numbers.
I have a slightly different problem. My external "Service Heater" display is illuminated. However, the heater seems to be functioning normally. I took off the cover and looked at the circuit board and the only error code that is lit is "ES1" on LED 8.
The manual says "ES1" is a spare. Not sure if I have a real problem or not.
The heater is approx. 12 years old and has never required service.