Zone Control System Troubleshooting
Note:
Take pictures of wiring before disconnecting from propert hook up later,
NEVER leave jumpers in place as the equipment will not turn off, leading
to potentially dangerous temperatures. Always disconnect 24vac
power to zone board before applying jumpers, reconnect 24vac power when
jumpers are in place.
Jumper Test to verify the HVAC equipment
Disconnect the low voltage wiring from the Zone control board equipment
terminals.
1.
Jumper R to W to verify furnace operation.
2.
Jumper R to G to verify fan operation.
3.
Jumper R to G and Y to verify HVAC operation.
If
HVAC equipment proves to be fully operational, then test zone board.
Jumper test to verify the Zone Board
1.
Disconnect both thermostats at board, remove wires.
You
must disconnect wires from board.
2.
Install jumpers from R to G on board terminals and verify fan
operation.
3.
While R to G jumper is installed, also jumper R to Y and see if
compressor starts (avoid short cycling, and wait 5 minutes in case board
time delays are delaying compressor start.
3B.
For Gas furnaces, jumper R to W or W1
3C.
For heat pumps, consult factory.
4. Do
above on zone 1, then zone 2. DO NOT leave jumpers in place as HVAC
unit will never turn off.
5.
Damper check: Both Dampers should be open when no stat is calling.
Opposite zone damper should close when jumpering zones.
Report
back. YOU MUST remove thermostat wiring from board for this test. If
zone board
If
HVAC unit performs as expected, the problem is likely in the thermostats
or wiring.
Jumper
Test to Verify the thermostat wiring. Kill power to zone board
before attempting.
1. At
thermostat location, remove thermostat from sub base. With
alligator clips, or with jumpers between thermostat terminals, jumper as
follows:
2.
Install jumpers from R to G on board terminals and verify fan
operation.
3.
While R to G jumper is installed, also jumper R to Y and see if
compressor starts (avoid short cycling, and wait 5 minutes in case board
time delays are delaying compressor start.
3B.
For Gas furnaces, jumper R to W or W1
3C.
For heat pumps, consult factory.
4. Do
above on zone 1, then zone 2. DO NOT leave jumpers in place as unit
will never turn off.
5.
Damper Check: Both Dampers should be open when no thermostat is calling.
Opposite zone damper should close when jumpering zones.
Temporary HVAC equipment use, in the event of a bad zone control board,
by jumping a thermostat to equipment wires. disconnect all 24vac power
first:
1.
Make sure all dampers are in the open position
2.
Disconnect both thermostat wires (1 thermostat only) and equipment wires
from panel
3.
Connect thermostat to equipment wiring , NOTE: if thermostat is of the
type to require a 24vac Common wire, this wire IS NOT used on zone
control board, and will not be present. Use only a thermostat that
requires no 24vac common wire (electro mechanical or battery powered)
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