Check that the Zoneline plug has been completely pushed into the corresponding electrical outlet, and inspect your home fuse and circuit breaker box if your unit doesn't turn on. If, on the other hand, you experience a power failure, set the "mode control" knob to the stop option and then, when the power is restored, return it to your desired setting.
Ensure no curtains, blinds or other items are obstructing the front of the Zoneline if it fails to properly cool or heat. Also, check that no items are blocking the rear grille, as this can lead to a compressor overlord. Additional options include adjusting the temperature control to a higher or cooler setting, cleaning the air filter and making certain all your windows are closed.
Turn on the fan switch if the heat pump is taking too long to heat your room. The increased air flow provides improved temperature distribution. Also, adjust the temperature by several degrees. This causes the unit to rely on its electric heating elements, which work faster but do use more electricity.