Install Instructions

Page 46
14
YES
Recheck
Wiring.
Replace
Control.
When there is no call to fire the burner, the voltage
should be 0 VAC on the gas valve.
Is there
24 VAC on
the Gas
Valve?
NO
Is the
Thermostat
(T-T) Calling
for Heat?
YES
YES
Is the
Indirect
(DHW) Calling
for Heat?
NO
NO
Is the
Red LED
(LOW WATER)
On?
The Control is
Sensing
Low Water.
WARNING!
TURN OFF POWER TO BURNER IMMEDIATELY!
CAUTION – ALWAYS ALLOW A BOILER TO FULLY COOL
BEFORE ADDING WATER.
Recheck wiring. Burner should never fire when
red or yellow LED’ are lit.
Is either
Yellow LED
On?
The Control has
Reached Target
or High Limit
Temperature.
The Control is
Operating
Normally.
The Control is
Operating
Normally.
The burner will continue to fire when there is a call
from the thermostat or external zone.
If there is no call for heat, there should be 0 VAC on
the gas valve.
If there is voltage, the control should be replaced.
Troubleshooting Flow Chart 2 – Burner Will Not Shut Down
YES
YES
NO
NO
11.C.2 Troubleshooting Flow Chart 2 (burners on)
WARNING
LAARS Heating Systems