Is the 1602 one that comes with a pre-set thermostat? If so you really shouldn't adjust it, regardless of what your thermometer says, until you've done a test hatch. Thermometers can be off by quite a lot.
No the 1602 is a wafer thermostat model with no fan.
If turning the thermostat up is not doing then something somewhere is wrong. Dont have enough information to guess but ether the environment is to cold, the thermostat is bad or the thermometer is bad.
Is it cycling on an off or is the light staying ether on or off?