Heat Pump HELP - I am home owner who needs help with my Heat Pump wiring.

[RWestman]

PLEASE HELP ME....

I have a heat pump system and I need help with the wiring. I am able to email or post pictures of the circuit board and wiring if that will help.

I have two problems:

1. Major problem: I have a temperature cutoff system installed on the system. However it appears it is NOT preventing the outside unit from coming on when the temperature falls to a certain temperature. Can someone please help me to determine if it is wired correctly or not?

2. Minor problem: I am not sure the defrost jumper is set to the best setting. I was told by a AC Technican it was set to 15 mins. I "believe" I have it set to 45 mins now. I would like have someone confirm I have it set to the best setting.

Any and all help will be greatly appreciated.

[hyperion]

What make and model of heat pump do you have?

[Peter_1]

Post pictures and schematics you have, your request os to general to answer.

[RWestman]

Model Info.jpgSwitch Relay.jpgBrand of Unit.jpgFirst, I want to thank you for replying. I really appreciate how people are willing to help others.

I am going to upload, at least I hope I do, pictures showing the name of the outside unit, the model number, and the metal box that holds the temperature cutoff switch with what I think is a relay the switch is normally plugged into.
I am wondering if the "relay" could be bad. I replaced the temperature cutoff switch and put a VOM on it before I installed it so I know it is working. I do not know how to check the relay. Then the question is: Do I need the relay? Shouldn't I be able to put the temperature cutoff switch in series with a low voltage circuit that would prevent the compressor system from coming on?
As for the schematic I was told if I provided the Brand and Model number the HVAC shops would have access to online sources to obtain the schematic.
Once again, thank you and please let me know if there is anything else I can provide to assist you.

[RWestman]

If you need a higher resolution picture I can email the picture to you. Please just give me your email address so I can send it.

Thank you,

Ron

[RWestman]

I am hoping someone will still be able and willing to help me. Is there anything else I can provide to assist you?

I would like to get this fixed before it gets too cold to be working outside.

Thank you.

[Gary]

1. Major problem: I have a temperature cutoff system installed on the system. However it appears it is NOT preventing the outside unit from coming on when the temperature falls to a certain temperature. Can someone please help me to determine if it is wired correctly or not?

It isn't supposed to prevent the outdoor unit from coming on in cold weather. The outdoor unit is what provides the heat for your house.

The temperature cutoff is supposed to prevent the unit from going into cooling mode... not prevent the outdoor unit from running.

[RWestman]

The temperature cut-out switches were added to prevent the outside unit from coming on when it gets TOO COLD and it is not effeicent to try to use the heat pump to heat the house. Most people have the switch set to around 35 degrees, at which point the Aux-Heat function provides all the heat.

[Gary]

2. Minor problem: I am not sure the defrost jumper is set to the best setting. I was told by a AC Technican it was set to 15 mins. I "believe" I have it set to 45 mins now. I would like have someone confirm I have it set to the best setting.

The correct setting is whatever is best for your system in your area. Here in Florida my heat pump is at the highest setting because my system rarely needs defrosting. In your area, you may need to defrost more often or your outdoor coil will turn into a block of ice. The downside is that it takes energy to defrost the coil. It's a trade-off.

You do NOT want a block of ice. If in doubt, set it to 15 minutes.

[Gary]

The temperature cut-out switches were added to prevent the outside unit from coming on when it gets TOO COLD and it is not effeicent to try to use the heat pump to heat the house. Most people have the switch set to around 35 degrees, at which point the Aux-Heat function provides all the heat.

What is your source of auxiliary heat?

[Gary]

I suspect you have it backwards. The cutoff switches lock out the auxiliary heat in warm weather, not lock out the heat pump in cold weather.

Why? Because the heat pump is more efficient than the auxiliary heat... even in the coldest weather and especially in the warmer weather. You (reluctantly) allow the aux heat to come on in very cold weather because the heat output from the heat pump has dropped to a point where it cannot do the job without the aux boost.

[RWestman]

The Aux-Heat source is electric heating elements in the inside unit.

So am I wrong in my thinking: If the outside temperature is, lets say, zero (0) degrees I would STILL want the outside unit to try to pull heat out of the outside to provide the heat source and the Aux-Heat function would be off? Doesn't make sense to me. It seems at some point the outside temperature would be too low to be efficent and the Aux-Heat would be the MOST efficent source of heat for the house. Therefore, the it seems the Temperature Cut-Out switch in the outside unit should be set to prevent the unit from trying to be the heat source.
Where am I wrong?

[Gary]

Even at sub zero temperatures, the heat pump is more efficient than the electric heaters. But at very low temperatures it just isn't big enough to keep the house warm. In very cold weather you will need to run the less efficient aux heat... in addition to the more efficient heat pump.

If you installed a heat pump that was big enough to keep the house warm in subzero temps, it would be WAY oversized for your cooling needs in the summer... and an oversized A/C runs very inefficiently.

[Gary]

At milder outdoor temps, the heat pump is big enough to keep the house warm without help from the less efficient electric heaters, so you want to shut off the aux heat and only run the heat pump.