Install Instructions

7
YES
Recheck
Wiring.
Replace
Control.
When there is no call to fire the burner, the voltage
should be 0 volts between B1 and B2.
 Make sure the burner is wired to B1.
YES
NO
Is the
Low Limit Dial
Set to OFF?
Is there
120 VAC between
B1 and B2?
NO
Is the
Thermostat
(T-T) Calling
for Heat?
YES
YES
Is the
External Zone
(ZC-ZR) Calling
for Heat?
NO
N
O
Is the
Red LED
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. Make sure that burner is wired to
B
1. Burner should never fire when red or yellow
LED is lit.
Is the
Yellow LED
On?
The Control is
Sensing High
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.
 Check temperature display. When the Low Limit is
set, the HydroStat will fire the burner until the
temperature reaches the Low Limit Setting.
If there is no call for heat (from T-T, ZC-ZR or Low
Limit), there should be 0 VAC between B1-B2.
 If there is voltage between B1-B2, the control
should be replaced.
Troubleshooting Flow Chart 2 – Burner Will Not Shut Down
YES
YES
NO
NO