Honeywell zone control acting strange

[JerryR]

We recently moved into a Florida home with a Trane 4 ton heat pump and a Honeywell Universal Mini-zone controller EMM-3U.

It has 2 zones wired with standard thermostats where the zone controller manages heat stages etc.

When heat is called for with thermostat in AUTO fan mode the unit operates as a heat pump with outside unit turning on. Last night I wanted to use fan manually to circulate air through the house to evenly distribute temp because we had fireplace running. To my surprise it was getting very hot in bedroom zone. I measured air intake temp at 72 dF and unit was outputting 101 dF from registers and indoor temp rose to almost 80 dF. . I went outside and the heat pump outside unit was idle so heat was being generated from the electric heat strips as if in Emergency heat mode. Both Thermostats were set to 68 dF. It seems in heat mode, when fan is set to "ON" via thermostat the electric heat strips turn on and compressor is idle when there is no call for heat.

The system initially had conventional single stage thermostats wired RWYG+C. I installed Filtrate Radio thermostats configured as non heat pump. I assumed that since it had conventional thermostats installed that the zone controller would manage the reversing valve being the thermostat did not have an O/B wire.

Here's a link to the zone controller manual
https://customer.honeywell.com/resources/techlit/TechLitDocuments/68-0000s/68-0237.pdf

Any ideas where to start looking?

 

[JerryR]

I just checked zone controller status lights. When one thermostat is set to fan ON, the controller FAN light and single zone light is on. Temp from registers slowly climb as if resistive heater elements are powered. Compressor is not running.

Also with cool/heat mode OFF and fan ON temps climb up. It's like the heater elements are wired to the fan relay.

JR

 

[Sponsor]

 

[DonL]

Is your system using separate transformers for heat and cool ?

The Heating relay must be getting power from somewhere if it is heating.

Maybe a Jumper is installed that should not be. Maybe check Dip switch #7.


Good Luck.

 

[JerryR]

Is your system using separate transformers for heat and cool ?

The Heating relay must be getting power from somewhere if it is heating.

Maybe a Jumper is installed that should not be. Maybe check Dip switch #7.


Good Luck.

BINGO.

Zone controller was mis-wired at output to Air Handler. Being that the same heat source is used for AUX Heat and Emergency heat, the instructions state to wire heat relay to W2, wire a jumper from E to W2 AND set DIP switch 12 to Off.

They had jumper between B and W2 and DIP switch 12 was set to ON.

I wired per instructions and set DIP switch 12 to OFF and everything is now working properly.

Ran through heat on and off. Cool on and off. Fan set to auto and on and heater relay does not come on. If I throw Emergency heat switch to ON, the heat pump does not come on and heat really energizes instead when there is a call for heat.

Later, if needed, I'll set timer DIP switches to turn on heat relay after set amount of time. I don't think I'll need to do this as the a/c puts out ample heat BTUs and there is lots of insulation in attic to retain heat.

Later I'll tackle the bedroom damper that will not close.

JR

 

[DonL]

Great that you got it working.

Good thing that you noticed the problem.


Enjoy.

 

[JerryR]

Don,

Last night, with heat pump working without "assistance" of the aux heater strips, the house temp was very comfortable. The air temp from registers was very comfortably warm, not hot as with the heat strips and heat pump both working at the same time the night before.

FYI, fireplace is propane gas, vented through the outside wall.

JR

 

[JerryR]

Later I'll tackle the bedroom damper that will not close.

JR

Well it turns out that the issue with the bedroom damper that would not close was with the zone Control logic. No matter what, it would never provide voltage to the damper motor to close.

I found a new Honeywell HZ322 zone controller on **** for $95. It arrived today and I had it wired and configured in 20 minutes. It was a piece of cake to program. I also like the digital display of the DATS, Discharge Air Temperature Sensor. Both Zones are now being signaled to open and close properly.

JR