Usually a minimum of 5: R (24 volt "hot")
G (fan signal)
W (heating signal)
Y (cooling signal)
O (reversing valve: usually energized for cooling)
Many also require a 6th:
W2 (2nd stage of heat--backup heat)
Some thermostats also require
C (24v "common")
More sophisticated systems may also require
Y2 (2nd stage cooling)
The HVAC Veteran
On a thermostat, "EM heating" stands for emergency heating. It heats your house up very quickly, and is costly to run. This is suppose to be used if you've lost heat from your heat pump or if you've turned your thermostat way down and need to heat up your house quickly.
If you have a heat pump A/C unit then you have auxillary heat and emergency heat. The EM stands for emergency heat, which is using only your electric heat strips or gas heat, depending on your system. The auxillary heat uses your compressor inside of your outside unit. Say the house is 60 degrees inside and you set your stat to 70, the temperature difference is so great that if the heat pump alone cannot satisfy, then the auxillary heat would come on to assist the heat pump. Say you were to get a leak in either your condenser or evaporator coils, your heat pump would not work on the regular heat setting on the tstat. In this circumstance you would want to use just the emergency heat until a service tech can evaluate the system.
I'm afraid your question is not very clear. Your heat pump is basically an air conditioning unit with back up heat strips. If your thermostat is wired correctly and I'm certain it was from the factory, then the AC and heat strips will never come on at the same time. Is it not going into cooling mode? Ruud has wiring diagrams for most all their equipment on the internet. With a little research, you should be able to find yours. The Model # of your heat pump is the key to that.
An electric heat pump can heat up your home during winter and cool it during summer.
Sounds like your system is a heat pump. When a heat pump cools in the summer, the inside coil gets cold and the outside coil gets hot. When the heat pump heats in the winter, the inside coil gets hot, and the outside coil gets cold. It sounds like your heat pump is stuck in heating mode. Check your thermostat to be sure it didn't accidentally get switched to heat. It could be the reversing valve inside the unit is stuck, or an electrical control is broken, forcing the reversing valve to stay in the heating position. Perhaps a call to the serviceman is in order!
A heat pump thermostat.
To properly wire a Honeywell thermostat for a heat pump system, follow the manufacturer's instructions provided with the thermostat. Typically, you will need to connect the wires from the thermostat to the corresponding terminals on the heat pump system. Make sure to turn off the power before wiring and double-check your connections to ensure they are correct. If you are unsure, it is recommended to consult a professional HVAC technician for assistance.
A programmable thermostat works fine with a heat pump. Just remember that a heat pump does not heat as fast as a furnace because of the lower BTU ratings so do not set the thermostat as far back as you normally would. Also make sure to buy a thermostat that has heat pump terminals.
The purpose of a thermostat on a heat pump is to regulate the temperature inside a building by controlling when the heat pump turns on and off. It helps maintain a comfortable indoor temperature by sensing the ambient temperature and signaling the heat pump to adjust its operation accordingly. The thermostat allows users to set their desired temperature and ensures that the heat pump operates efficiently.
First, is the thermostat in he correct position for cooling? Is there a red light glowing on the thermostat? There could have been a power surge or outage and the heat pump needs to reset. Turn the power off to the heat pump at the control panel for a couple or minutes then back on again to reset the heat pump.
Any brand or make will work if it is 2 heat 1 cool thermostat
IF THIS IS NOT A HEAT PUMP SYSTEM... COULD BE; thermostat connecting(calling for) heat and cool together. connnection problem in wires- or bad thermostat. find wiring diagram for t-stat, read up on checking voltage in thermostat in the heat-or cool mode. they are separate. does t-stat have separate 'heat-cool' mode. in other words- do you have to switch to heat mode-or cool mode. if it is a heat pump--ask again with that stated in question.
yes it can but everytime you want heat you have to put it on Emergency Heat..
To optimize the performance of your heat pump with a Nest thermostat, you can set a schedule that aligns with your daily routine, enable the learning features of the thermostat, and adjust the temperature settings to maximize energy efficiency.
The outdoor thermostat in a heat pump system helps regulate the system's operation based on the outside temperature. It ensures the heat pump runs efficiently by adjusting the heating or cooling output according to the outdoor conditions.
If you have a Heat pump, you must set the thermostat up for "heat pump". Then you must connect all the wires up according to the manual. If you do not have a heat pump, the wiring may be crossed or touching somewhere. Call a local heating and air conditioning company to trace out the problem.
The purpose of the orange wire on a thermostat is to connect the thermostat to the heat pump, allowing it to control the heating system.