My air handler is freezing up and I have to shut it off to get it to unfreeze.any ideals would be welcome.

Replace dirty filter if necessary.
Check inside coil for dirt blockage.
Make sure all return air and supply air ducts are open.
Make sure the blower motor inside the air handler is working correctly.
The next step you will need help on. If the unit is low on refrigerant it can and will cause the unit to freeze up. This will have to be checked by a professional.

The coils have been cleaned return is also clean so I guess it's off to the repair man.
Thanks