GSA
Gas-Fired Steam Boilers –
Boiler Manual
24
Part Number 550-110-738/0703
12 Troubleshooting
Verify proper operation after servicing. • See vent
damper manufacturer’s instructions packed with vent
damper for additional information. Failure to comply
could result in severe personal injury, death or
substantial property damage.
Figure 15
Manually opening vent damper
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation.
Never jumper (bypass) rollout thermal fuse element
or any other device except for momentary testing as
outlined in “Chart 1”, page 25. Severe personal injury,
death or substantial property damage can result.
Burner base access panel must be in position during
boiler operation to prevent momentary flame rollout
on ignition of main flame. Severe personal injury or
substantial property damage will result.
Before troubleshooting:
1. Have the following items:
a. Voltmeter that can check 120 VAC and 24 VAC.
b.
Continuity checker.
c. U-tube manometer.
2. Check for 120 VAC (minimum 102 VAC to maximum 132 VAC)
to boiler.
3. Make sure thermostat is calling for heat and contacts (including
appropriate zone controls) are closed. Check for 24 VAC
between thermostat wire nuts and ground.
Troubleshooting sequence:
1. Before proceeding, check for:
•
Loose connections, blown fuse or service switch off?
•
High limit switch set below boiler water temperature?
•
Thermostat set below room temperature?
•
Gas not turned on at meter or boiler?
•
Incoming gas pressure less than:
5" w.c. for natural gas? 11" w.c. for propane gas?
2. If all of the above check correctly, check gas pressures:
a. With boiler off:
•
13" w.c. maximum natural or propane gas pressure
upstream of gas valve.
b.
With boiler on:
•
5" w.c. minimum natural gas pressure or 11" w.c.
propane gas pressure upstream of gas valve.
•
3.5" w.c. minimum natural gas pressure or 10" w.c.
propane gas pressure downstream tapping on gas
valve — Can be adjusted by regulator on gas valve.
c. If gas pressure is incorrect or gas is not available to boiler,
contact gas supplier to correct before proceeding further.
3. Check pilot operation — Follow “Lighting Instructions”, pages
18 and 19.
•
If gas is available and you cannot obtain a pilot flame, try
purging the gas line and cleaning pilot and pilot gas tubing.
Follow “Lighting Instructions” again. If you still cannot obtain
a flame, replace pilot burner and gas tubing. If this does not
allow you to obtain a pilot flame, replace gas valve.
•
If you obtain a pilot flame, but pilot will not remain on, replace
thermocouple. If this does not correct problem, replace gas
valve and pilot burner.
•
If pilot stays on, but main gas will not come on, proceed to
page 25.
In event of vent damper failure:
Effikal vent damper
If troubleshooting chart recommends replacing actuator and actuator
is not immediately available, damper blade can be fixed in an open
position to allow boiler operation. Manually turning blade can cause
actuator damage. Follow these instructions only in case of no heat
or damper actuator malfunction.
1.
Move damper service switch to Hold Damper Open position.
Apply call for heat to boiler. Damper blade should then rotate to
Open position and boiler will fire.
2. If step 1 does not open damper, manually rotate damper blade
to open position using wrench or pliers on flat shaft between
damper and actuator. Boiler will fire. Verify that damper service
switch is in Hold Damper Open position. See Figure 15.
3. Do not leave vent damper permanently in this position. Replace
actuator immediately. If vent damper is left in Open position,
boiler will not operate at published efficiencies.
Johnson Controls vent damper
If troubleshooting chart recommends replacing actuator and actuator
is not immediately available, damper blade can be fixed in an open
position to allow boiler operation. Follow these instructions only in
case of no heat or damper actuator malfunction. See Figure 15.
1. Turn off power to boiler.
Failure to turn off power to boiler can result in severe
personal injury, death or substantial property damage.
2. See vent damper manufacturer’s instructions for procedure to
fix vent damper in open position.
3. Turn on power to boiler.
4. Using wrench or pliers on flat shaft section, manually rotate
damper blade until green light turns on. Boiler will fire. See
Figure 15.
5. Do not leave vent damper permanently in this position. Replace
actuator immediately. If vent damper is left in Open position,
boiler will not operate at published efficiencies.