Flagro FVO-400 Operating Instructions Manual page 11

If supply air is cold (under -5ºC):
Turn the temperature feeler gauge so that the holes are closed off as the air goes
over the heat exchanger. This will reduce fan cycling and the unit from shutting
down. See following:
In extreme cold conditions, cover the holes on the temperature feeler gauge using
foil tape. Ensure that the temperature feeler gauge is readjusted for warmer
weather conditions. Failure to do so may result in burning out fan switches- not
covered under warranty.
POWER SUPPLY INDICATOR LIGHT:
The power supply indicator light will help detect any faulty power supplied to the
heater such as; grounding issues, reverse polarity or missing/poor connections.
Warning Light Indications
Green Light .................. Meets Power Requirements
Solid Red Light.............. Reverse Polarity
Solid Red & Green Light... Ground Issue
ATTENTION: IF SOLID RED & GREEN IS INDICATED, MAKE CORRECTIONS
TO POWER SUPPLY BEFORE TURNING HEATER ON. FAILURE TO DO SO
WILL VOID ANY WARRANTY.
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