Thermostat 44360 is flashing ERR. What can I do? Freezing here!

There should be a tiny unmarked hole in the front of the thermostat....if so, the thermostat 'reset' micro-switch should be under that hole. Gently stick a thin toothpick inside to depress the switch and get ready to operate it manually.

If there is no hole, separate the thermostat from its sub-base and look closely at the sub-base for a reset button.

Filter change indicator - will flash after 400 hours of system use as a reminder to check or change your filter. Press and hold the Filter button for 3 seconds after changing the filter to reset the filter timer. (Pressing the Filter button for less than 3 seconds will cause the Filter change indicator icon to appear. The filter timer will not be affected unless the button is held for more than 3 seconds.) Note: Clearing the Filter counter will also clear the Energy counter.

Just hold down the two buttons for 5 seconds and it will be reprogrammed.

Good luck.

Try this URL. Should be able to download it for free.
http://homeappliance.manualsonline.com/manuals/mfg/hunter/44360.html

Click on the above link. If that doesn't work for you, copy and paste it into your browser's URL line.

List of things to check:

Are the batteries good?
Is the system switch set to heat, and not cool?
Does the fan come on when you set the fan switch to ON?

If none of these things seem to be the problem, call hunter fan tech support at 1-888-830-1326

If you don't have the wiring information, go here: http://www.hunterfanhq.com/tools/sales/hunter/preseason/images/owners/42710.pdf and see page 10.  
If you're still having problems, go down to the furnace room and find the piece of equipment that you're wiring to.  See where the wires came from, transpose that to the information above.  Note: the wiring from the relay box should be 24 volts which is safe to handle.  Wiring inside the relay box may be 110 or more volts which is not!!!  Cut power before opening relay boxes.
As far as heater running continuously, be sure of your wiring.  You may have the gas relay lead and the fan lead reversed.  Determine if you've set the switch options for your type of heater correctly!!!  Do you hear the relay clicking in and out at or near the room temp when you change the setpoint?  If not, the unit may be defective.

You probably have one of the wires reversed or have the options set incorrectly as to what type of heater you have.  Check your instructions here: http://www.hunterfanhq.com/tools/sales/hunter/preseason/images/owners/42710.pdf

turn key to <acc> turn radio will blink err. leave on for at least half hour.err will be replaced by enter code.

OMG! has anyone came up with a solution? I have the same problem as mlc3530b

The message means the tstat was in recovery mode, I would suggest just disabling this function to prevent it in the future. Remove the tstat from its base and look on the back there will be a recovery switch just slide it to the other setting to disable the feature