DIY Home Improvement Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #1 ·
My Carrier heat pump with the Edge thermostat is turning on the emergency electric back up elements when I switch thermostat on heat mode (not EM HEAT). Did it this morning thermostat was in cool mode and reading 67 degrees, turned system to heat mode and set thermostat to 69 degrees. System turned on, no Emergency or Auxiliary heat indicated on thermostat, outside unit running. Within a few minutes we could smell the dust burning off the heat elements, outside unit still running and no EM. Heat indicated on thermostat.
Read through manual on thermostat and could not locate anything that pertains to this issue. Oh it is 59 degrees outside.
Any suggestions?
Thanks
Kevin
 

·
Hvac Pro
Joined
·
23,688 Posts
EM emergency heat is when you turn it on manually to overide the heat pump.
Auxiliary heat is when it cannot keep up with the heat demand.

If you set it to heat and your setpoint was 2 degrees higher than the room temp it may turn on the Aux heat. Was it showing Aux heat? You said no EM heat but was the Aux heat on?

There may be a time delay B4 it kicks in the Aux heat.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #3 ·
No auxiliary indicator was on, the old system and thermostat had a 3 degree setting difference before auxiliary heat was activated. I guess I will have to try raising temp one degree at a time. I find it hard to believe that the system / thermostat would initiate auxiliary heat every time a two degree change is made. especially when it has the set back features for raising and lowering for different times.
 

·
Hvac Pro
Joined
·
23,688 Posts
Normally modern electronic thermostats have a .5 deg differential ( deadband ) between cut in and out.

Meaning they don't usually drop a full deg F B4 turning on the AC so you don't notice the air feeling too hot or cold. There is a electronic heat anticipator/cycles adjustment per hour to smooth it out but the days of dropping 1 to 1.5 deg B4 the heat cut in are gone.

Point is 2 deg F may be past their comfort deadband and yeah if you use setback that may override the deadband in the program BUT if you are running it just basic on/off it may go to Aux.

With a 2 stage gas furnace you if you drop more than 1 deg F it kicks in the second stage.
 

·
Registered
Joined
·
15,632 Posts
Some stats allow a droop/differential to be set for aux heat, check the install manually carefully.

Really good ones can lock out the aux heat above a certain outdoor temp.

Honeywell and some others use an algorithm instead of fixed differential for staging.

Basic cir source heatpumps are set it and forget it systems (at least in heating mode), raising and lowing the temp thorough the day is a bad idea - wastes energy on aux heat and the capacity to recover quickly just isn't there.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #6 ·
Thanks for the replies, will read the thermostat manual again. I had read the the owners manual with no luck, however I found the installation instruction manual and it goes into more depth on the thermostat and its programming process.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #7 ·
Well, I think I may have found my issue. "Auxiliary Heat Lockout Temperature" This selection is available on heat pump systems with a valid outdoor temperature sensor connected. Available settings, Off then 5 - 55 degrees in 5 degree increments. Default is OFF which allows aux. to operate when ever sufficient demand for heat is available.
I also found the outdoor sensor in the box the thermostat came in.
 

·
Hvac Pro
Joined
·
23,688 Posts
Good 4 U.:smile:

Yeah you need the install manuals to get into the specific features not the owners manual.

Default positions/settings are usually pretty neutral and generic and setbacks etc are custom settings. They also keep it neutral for older people or those that feel colder quickly etc so they/we can run it in basic mode and keep it simple.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #9 ·
Good 4 U.:smile:

Yeah you need the install manuals to get into the specific features not the owners manual.

Default positions/settings are usually pretty neutral and generic and setbacks etc are custom settings. They also keep it neutral for older people or those that feel colder quickly etc so they/we can run it in basic mode and keep it simple.
Plus it takes time to put the sensor in correctly on the north side of home for optimal sensing of outside temp. So they don't disclose it to the owner. Sad install.
 

·
Hvac Pro
Joined
·
23,688 Posts
Try keep it out of direct sunlight.

Yeah it is sad when you pay good money and don't always get good results. That is why we are here to help.:thumbsup:
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top