I can't find error codes list either. What is the heater doing. Is the blower running? I have replaced the air detection switch in these heaters before.
Other things to check is for any loose wires too
Thanks for your reply. Nothing is happening with the heater, no blower or other sounds. When turned on the display flashes a few codes (self-diagnostics I assume), then the Service light and error codes appear. Got a service man coming Wed, he didn't seem too worried.
Let us know what it was.
Mystery solved! Some rats (or other small rodent) made a nest inside...and they chewed thru some wires. Cleaned out the leaves & twigs, replaced the wires & all was well!
Thanks all.