off topic, Webasto Vs.Espar

[Cornbinder89]

Does anyone know if the 7 day timers for Webasto and Espar heaters are interchangeable? They are both made by Hella and look identical except for the logo on the face. Both have a diagnoictic function, and not sure if the guts from one can talk to the other?
For those that don't know what these are, they are aux heaters, either gas or diesel and heat the air or coolant.

[Cornbinder89]

I got a Webasto timer and tried it on an Espar heater, it will control it, but will not read the trouble codes, so while similar, they are not one and the same.