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VI
CTORY VSPH Models
26
CAUSE
8. Defective pressure switch. POWER and PRES SWITCH
LED’s flashing
9. Defective high limit control
10. Defective inducer motor
11. Defective gas valve
12. Defective boiler control module
REMEDY
8. Check pressure switch. Replace defective pressure switch.
9. Set high limit setting above boiler water temperature, LIMIT
L
ED should turn on. If not, turn off power to the boiler,
r
emove wires to high limit and check continuity across high
limit contacts. If contacts are open, replace high limit.
10. With thermostat calling for heat and high limit setting above
boiler water temperature, remove blower motor plug from
boiler control (P4 connector). Check for 120 V between ter-
minally 3 and 5 of P4 on control (See Figure 13a and 13b).
If voltmeter indicates 120V, replace inducer assembly.
11. a. Check all above causes.
b. check the gas supply pressure (at the inlet of gas valve)
as shown on the boiler rating plate for the type of gas
used.
c. With thermostat calling for heat and high limit setting
above water temperature, check the voltage across terminal
PV & PV/MV, if 24 VAC presents, replace the gas valve
12. Check all above causes. If all red indicator lights are off
while there is call for heat replace control module.
B. NOT ENOUGH HEAT
CAUSE
1. Thermostat setting is too low
2. Boiler water maintained at too low temperature.
3. Circulator not running.
4. Boiler water level too low.
5. Restriction or obstruction in air intake or venting system.
REMEDY
1. Set thermostat at higher setting
2. Set Aquastat at higher setting.
3. With thermostat calling for heat, check for power to circula-
tor. If power is O.K but circulator is not running, replace cir-
culator.
4. Carefully snap open relief valve handle to determine if boil-
er is full of water, if not full of water, check for system leaks
and check water pressure regulator. Repair any system
leaks. Adjust or replace water pressure reducing valve.
5. Inspect flue and air intake piping. Inspect termination.
C. BURNER WILL NOT SHUT OFF
CAUSE
1. Defective Aquastat (high limit control)
2. Aquastat sensor is not proper
ly inside Aquastat well.
REMEDY
1. Turn off power to the boiler. Remove red and blue wire from
Aquastat ter
minals. Restore power. Check boiler operation,
if burners stop firing, replace Aquastat.
2. Inser
t the sensor into the well.