Honeywell CM721 - CM721 Troubleshooting; Display and Battery Issues; Service and Communication Faults

7
Symptom
BlankDisplay(PowerLoss).
Displayshowsashing
symbol.
Displayshows symbol.
Displayshowstheword'SERVICE'
BDR91redLEDisconstantlyon
orashing
Remedy
Checkbatteriesareinstalledbyremovingthebattery
cover.
Checkbatterieshavebeeninstalledinthecorrect
orientation.
Replacethebatteries.
Thebatteriesinthethermostatarelowonpower
-Replacethebatteries.
Afaulthasoccurredinyourheatingsystem.Remove
andre-insertthebatteries.
Ifthe symboldoesnotclearafterafewminutes
contactyourinstaller.
Your installer has set a scheduled maintenance alert
period on your CM721 as a recommendation that your
heating system should receive a routine inspection.
Call your installer to arrange a maintenance visit.
Note: The CM721 and heating system will continue to
operate as normal.
RF communication lost due to the wrong location of
the room unit - Hook the room unit back on the wall
bracket where RF communication was reliable.
Call installer
NOTE: You can control the boiler manually when the
RF communication is lost: Press the BDR91 push
button to switch the boiler on and off. When the green
LED is on – the boiler is on.
TROUBLESHOOTING THE CM721