I have an intertherm rpbmb030k combo a/c and heat. Had frion put in the unit over the summer and a new digital thermostat. Unit has worked great until we needed heat. Unit works great on aux. heat but keeps switching to to defrost mode when standard heat is on. Switched out the defrost board on the unit to no avail and an a/c guy checked to ensure the new thermostat was wired correctly.

if temp sensor ok possible stuck fan relay

actually what is ur problem??

can u be clear with the problem?

There is no antifreeze in the system. The system is filled with liquid gas and gaseous gas. On the heating cycle, the inside coils should get hot and the outside coils should get cold. In the summer, the heat pump reverses to provide Air Conditioning, the outside coils get hot and the inside coils get cold. They shouldn't really ice up because there is a defrost cycle. You need professional service by an Intertherm technician.

I think your blower fan contactor not energized. Check your thermostat sett ing also and then call arepairman. It's simple fault only.

On some thermostats there is a delay when you first apply power. Look at the owner's manual and see if this applies to you.

The model of T-stat you gave comes up as a discontinued model on Honeywell's web site, but it looks to be a manual stat that type of stat would have to be wired with a summer winter switch with electric heat, allowing it to turn on the fan with a call for heat. If yours is a programmable T-stat you would need to select electric heat or in the installers set up change the default setting for fan from unit controls fan in heat to thermostat controls fan.

I would not blame the manufacture sound like the clowns that installed it. Tom

My heating unit is blowing cool air. The thermostat will start the blower when the unit is turned on at the thermostat, but the air isn't hot. But,when I turn the unit on at the furnace/blower using the "Fan On" button, I can see the heating element heat up. After the blower starts the heating element does out. What could be the problem?

FIRST YOUR OUTSIDE UNIT PROVIDES HEAT BY USING A REVERSING VALVE TO CHANGE THE REFRIGERANT FLOW.THERE IS NO HEAT STRIPS OUTSIDE SECOND YOUR EMERGENCY HEAT TURNS ON ELECTRIC ELEMENTS INSIDE YOUR AIRHANDLER UNIT.IT SOUNDS LIKE SOMEONE HAS WIRED YOUR UNIT WRONG OR HAS THE THERMOSTAT SET IMPROPERLY.WHEN THE HEAT PUMP CANNOT SATTISFY THE SETPOINT THE THERMOSTAT IS SUPPOSED TO TURN ON YOUR ELEC. HEAT UNTILL THE LOAD HAS BEEN REACHED AND THE HEAT PUMP CAN CONTINUE TO MAINTAIN IT.

Typically if you have a yellow wire in the "y" terminal blue is used as common or "c". As far as your jumper from rc to rh, that will depend upon what type of heat you have. If all of your heat and cooling come from your packaged unit outside, yes you will need the jumper. If this does not work maybe you have a bad breaker or transfomer.