THE FAN WONT SHUT DOWN ON MY DUCTED HEATING. THE HEAT DOES BUT NOT THE FAN. IT SEEMS THAT THE ON/OFF BUTTON ON THE WALL UNIT IS NOT WORKING. THERE IS NO REMOTE CONTROL FOR IT.

all units have a thermal fuse that stops operation when case over heats . try replacing the thermal fuse could be out of tolerance.. looking for an obstruction in the high voltage radiation ducting that could be obstructing the flow of high voltage radiation , or the defuser belt or motor is no good or slipping, also the cooling fan obstructed or failed. .. all above to be handled by a master or journey man teck. or tv repairman. A professional not an novice.

When any unit 1st come's on, you'll always have some cold air that's in the ducts that will blow out before you get warm air. If your duct work is uninsulated in a cold basement or crawl space then it will be even more noticeable. When the unit is heating from the Heat Pump mode, it takes a little longer for the gases to get warm enough so you'll fell heat. When it gets cold enough for the unit to switch from heat pump to the gas or electric heat source, you'll get warm air faster. If you have gas heat, some Thermostats have an anticipator setting for the gas valve. If it's set wrong it will effect the on/off cycle of the gas valve.
All duct work in non heated and a/c spaces, including inside walls,above dropped ceilings, in attics and crawl spaces, must be sealed & taped at the seams and joints and then insulated and taped.
Most new construction has solved that problem with insulated duct board, flexible insulated supply's and special tape.

the cpu could be over heating make sure its secure if you like get some thermal paste from your local pc world put a little on the top of the cpu under the cpu fan and replace fan securely might work be carefull....bonnell

this may help, Tim:

http://appliancejunk.com/forums/index.php?topic=508.0

First, check the duct work! The most common "no heat" problems with dryers are caused by duct work blockage. If your duct is blocked, it will overheat the unit, causing it to shut down the heat source (gas or electric, it doesn't matter). Most units will continue to "blow" without the heat. Remove the duct work, remove all lint from the duct and "exit" port of the unit. Then, check the wall duct, both inside and outside the house.

I watched your video on youtube. Sounds like a seized compressor. Do you know if it is reverse cycle or electric heat?

On the unit outside there is a button that says "push man. pull auto" if it is set to push man then the fan will go constantly.

This could be one of several problems. The most common problem that causes no heat is a clogged duct or vent. If air is not flowing out of your unit due to a clogged vent or duct, it will immediately overheat and shut down the gas burner, in gas models or the calrod heating system in the electric models. Try removing duct, checking for clogs in the duct and at the connector at the unit itself. Then check the vent inside your home and on the outside wall for lint clogs.

I have been without heating for the past month since the fan motor in my ducted gas brivis heater filled the house with smoke.
The guy replaced the fan motor, and then it had the same symptoms as yours.
After a month of various tradesman trying to work it out, it has come down to the "thermal switch" within the unit.