Eheim 2126 Thermofilter heater broken

I own an Eheim 2126 Thermofilter with integrated heater. It appears
that the heater control module or sensor is broken because the module
LCD reads "0.00". I'm not sure if something is shorted out or what
(well some water might have gotten into the unit) so MAYBE it will dry
out and work in a few days. But in the event it doesn't, where can I
buy a replacement sensor and module?

And is it worth it to replace it or should I just buy some $20 separate
heater instead and just unplug the heater part? (Thus essentially
ending up with the 2026 Filter). The filter itself is still working
well, just the heater isn't working. Anyone with experience on whether
the heater part of the thermofilter is long term reliable or is this
break down unfortunately "normal"?

(Replies here please, I don't read any email, Thanks!)