13
Part Number 550-110-031/1112
Control Supplement — Standing Pilot Boilers
Verify proper operation after servicing
Never jumper (bypass) any device except for momentary
testing as outlined in troubleshooting chart below. Sub-
stantial property damage and/or severe personal injury
could occur.
Burner access panel must be in position during boiler
operation to prevent momentary flame rollout on igni-
tion of main flame. Severe personal injury or substantial
property damage will result.
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and danger-
ous operation leading to severe personal injury, death
or substantial property damage.
Before troubleshooting:
1. Have a voltmeter that can check 120VAC, 24VAC, and a continuity tester.
2. Check for 120VAC (minimum 102 to maximum 132) to boiler.
3. Be sure pilot is lit. See “Lighting instructions” on page 12 for details.
4. Make sure thermostat is calling for heat and contacts (including appro-
priate zone controls) are closed. Check for 24VAC between thermostat
wire nuts and ground.
Pilot does not stay lit — Troubleshooting
thermopile and high limit control circuit
1. Checking thermopile open system (Figure 5):
a. Use an electronic multimeter, with leads fitted with alligator clips.
SetmeterscaletoDCMillivolts.
b. Unscrew thermopile fitting from gas valve.
c. Attach one meter lead to the end of the thermopile gas valve fitting.
d. Attach other meter lead to thermopile lead (copper surface).
e. Follow Lighting Instruction label on boiler (also found in Control
Supplement or User’s Information manual) to light the pilot burner
onlyand holdthe pilot amemanually.(DONOTlight main
burner.)
f. Check the reading on the multimeter. The reading should be around
700 millivolts.
g. If multimeter reading is significantly less than above, replace the
thermopile.
2. Checking thermopile circuit closed system (Figure 6):
a. Use an electronic multimeter, with leads fitted with alligator clips.
SetmeterscaletoDCMillivolts.
b. Loosen the insulated terminal on the TOP thermopile lead wire
enough to allow clipping a multimeter alligator clip to the spade
terminal.
c. Attach the other multimeter lead to the thermopile lead.
d. Check the reading on the multimeter. The reading should be around
400 millivolts.
e. If reading is significantly less than 400 millivolts, check tightness
of lead wire assembly in gas valve. If the connections are secure
and you have checked the thermopile per step 1 above, replace the
thermopile lead wire assembly.
Figure 5
Figure 6
f. If reading on TOP thermopile lead wire is
around 400 millivolts, move the multimeter
alligator clip to the BOTTOM thermopile lead
wire terminal and check multimeter reading.
g. If multimeter does not read around 400 mil-
livolts, check wiring connections and wire
integrity to the limit controls.
h. Check voltage at each limit terminal to make
sure limit is closed. Correct pressure or tem-
perature condition causing any limit to be open.
Replace limit if necessary.
Troubleshooting
(2 pages)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comments to this Manuals