Honeywell envirazone panel w8835 User Manual

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68-0258—04

The C7835A1009 Discharge Air Temperature Sensor (included 

in the Y8835 kits) is a supply-duct-mounted temperature 

sensor probe used to control capacity and prevent high plenum 

temperatures or coil-icing. The sensor is wired to the 

EnviraCom bus using three wires. When a high or low limit is 

reached, the panel shuts off the equipment and keeps the fan 

operating for a minimum of two and one-half minutes. After this 

time, and any applicable minimum-off times imposed by the 

HVAC equipment. It re-energizes the equipment when the 

discharge air has recovered by ten degrees. When the high or 

low limit is exceeded, the Heat (red) or Cool (green) LED on 

the DATS flashes.

When the DATS is in a limit condition, the Heat, Cool and 

Purge LEDs on the W8835 panel continue to operate as if the 

DATS were not turning the equipment off.

The high and low limit is set on the DATS. The high 

temperature limit is set from 110°F to 160°F with a small 

screwdriver or using fingers and the low limit is set at 40°F or 

48°F degrees with a jumper.

A built-in thermal circuit breaker protects the EnviraZone panel 

against shorts in the damper wiring and EnviraCom bus. It 

does not protect against shorts in the HVAC equipment wiring 

into the panel.

When the circuit breaker is tripped, none of the LEDs illuminate 

and the yellow rectangular component located bottom center 

on the panel is hot to touch. 

• Remove power to the panel for at least five minutes to allow 

the circuit breaker to cool off and reset. 

• To eliminate the short, verify the dampers and transformer 

wiring.

The system blower can be set to come on with a call for heat 

as required for hydro-air or electric heat systems. Set the 

blower function using DIP switch 8. When configured for heat 

pump, this DIP switch is not used.

Connect one W8703 to the EnviraCom bus to expand the 

system up to six zones or connect two W8703 to control up to 

nine zones: 

• Wire the first three zone dampers and thermostats to the 

W8835 Envirazone Panel. 

• Wire the additional dampers to the W8703 panels.

• Set the DIP switches on the W8703 to correspond to the 

zones being controlled. See W8703 Installation Instructions.

• Wire terminals 1, 2, and 3 from the additional thermostats to 

terminals 1, 2, and 3 on any of the panels.

Off (Down)

Fan on in heat by panel.

On (Up)

HVAC control of fan.

No LEDs are Illuminated.

No power to the board.

Check for 24 Vac (±10%) across R and C.

Transformers out of phase.

If 48 Vac across R and T1, reverse T1 and T2 wires.

Shorted wire.

Check thermal circuit breaker. If hot, a short exists in wiring.

Damper LEDs on, but no 

other LEDs illuminate on a 

call for heat, cool, or fan.

Insufficient voltage.

Check for 24 Vac (±10%) across R and C.

Incorrect configuration.

Check jumpers and DIP switches for correct configuration.

Heat pump operates 

incorrectly or not at all.

Incorrect wiring.

Verify equipment terminals wiring.

Incorrect configuration.

Verify DIP switches configuration.

No damper LEDs are 

illuminated.

Incorrect configuration.

Verify that XFRM jumpers are set correctly.

Error 35 or 39 message on 

thermostats.

Incorrect zone numbers.

Verify the thermostat zone numbers are set correctly (1,2,3 etc)

Wait is continuously in the 

thermostat display

Incorrect configuration

Verify dip switch 3 is set to conventional (Up) position.  If 
controlling a heat pump, verify that thermostats are not configured 
to lockout the compressor  based on outdoor temperature.
(This feature is not used on zoned applications)