How accurate are the inverter temps? My F3600 regularly shows greater than 50°C temps but last night at midnight, for instance, it was showing 29 with vane temps of 20 with the inverter off for 5 hours. It was cool last night! Vane temps show approx 6° higher than my thermostat. Can I calibrate/check the temps? Will a false reading impact on inverter performance? I have a fan above the inverter blowing downwards but can't hold the temperature steady.