Simple answer, as a test unplug the external and see what happens with the internal for a couple of days. Not forgetting you will need to setup new timers and such.
However if it works OK on the internal you do have your answer. Actually if it still acts up, then Bye bye HR-20 IMO of course.
Good Luck
However if it works OK on the internal you do have your answer. Actually if it still acts up, then Bye bye HR-20 IMO of course.
Good Luck