Carrier heatpump model 25hba324a300 unit will not supply heat.outside unit constantly comes on and goes off .works well in a/c mode.

Installed how recently, by whom? Call installer!

Really not efficent to run a heat pump at those temperatures. Below freezing is not good for the compressor in the outside unit. The humidity in the house with the low temp. is causing the condensation on the windows to freeze. Kinda like an air conditoner does in the summer without the freezing humid air from the house goes over the cold a/c coil and the moisture condensates on the coil running down to drain pan. raising the temp. in the house and lowering the humidity should help. I would also recommend running the electric heat in low outside teperatures.

These Ge Zonelines have and ambiant Temp control on the unit when the temp drops it drops out the compressor and goes to electric heat. This keeps the unit from getting iced up. They do go bad and sometimes they shut off to soon. I just replace them and everything goes back to normal. They are located on the outside part of the unit. Just slide out the unit and it is located I beleive on the right side of unit Rus.

Hi there, I know that this unit is made in South Africa and it is well built and designed. The problem sounds like a condensation problem, and instead of the water draining at the condensate line hose, or pipe, it is over flowing into the electrical components causing the unit to trip loosing power .I have not been able to locate a manual to read what the codes for this unit mean, but you need to look at the unit where the water is coming from, the evap. coil where it blows supply air and clean the drain and if it has a foam type filter that can be washed, do this also.The drain must be washed or blew out or you will continue to have this problem, which can also be dangerous as you no that water and electrical products do not mix. If it will not come back on now after the water has drained, it sounds like the water has finally damaged a component. Find out what you can on this code from owners manual if you have one. Sometimes you will find a list of codes on the unit also, that will tell you what so many short or long flashes mean. I would bet the water has shorted out a component.Lets hope not, try and find what this code means and we can go from there.It would be great to be on site to get you up and running,but....no such Luck. It only condesates in the cooling mode inside the house. Please inform me what you find.
Sincerely, Shastalaker7

The outdoor thermostat senses the the temp of the outside air, and adjust the boiler water temp according to what it knows is best. The reason that the boiler is running longer is the old boiler used to be constantly sending 180ish degree water to the baseboard, now that water may only be 140ish degrees. The idea behind this is to reduce off cycle heat loss, as the greater the temp difference between the air temp and water temp, the quicker you loss heat. The theory in boiler run time is this, the less times it starts and stops, and the long run times will give you the best efficiency. Hope this answers you questions.

When your unit is on normal the outside unit works and the inside only the fan runs. your heat pump does not remove any humidity when it operates so the installation cotractor did not wire it to operate then. you can change the wiring on the humidifier to operate all the time by wiring it to the fan (g) terminal then it should work just turn it all the way to the lowest humidity when you are in cooling mode.

J-

I had this problem several years ago. In order for the water to flow, the outside temperature sending unit must indicate to the controller that it is less than 60F. If not, the unit will not operate outside of test mode. Check the temp outside where your sending unit is (could the sun be heating that side of the house?) and ensure that the circuit to the sending unit is working. I had a bad wire splice inside a wire nut stopping the circuit. Took me a long while to figure it out.

If the outside temp and your sending unit circuit is ok, I wish you luck on your troubleshooting.

adx_98

Try this link:

http://yourhome.honeywell.com/yourhome/Applications/TechLit/TechLitSearchResults.aspx

It looks like there are a variety of model numbers for the Chronotherm III. Hopefully you can locate your model number.

Call Aprilaire and tell them, this is happining everywhere

Have you checked the position and function of the floats in the pan?