Weil-McLain ULTRA ULTRA-105 Service Manual page 25

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GAS FIRED WATER BOILER SERIES
Troubleshooting
Troubleshooting procedures (continued)
Boiler not firing and: Check for:
Display first digit shows
0 and last digits show 2
or 3-digit number (boiler
outlet water temperature).
Part number 550-100-029/0810
(continued)
Are room thermostat and DHW
aquastat satisfied?
Is room thermostat or DHW
aquastat calling for heat?
Does display intermittently show 0
for outlet water temperature?
Is blower running on low?
Is room thermostat or DHW calling
for heat, but boiler is not firing?
Check information mode, #4 —
does display show 4.230?
—
1 & 2
Corrective actions:
1 If yes, then boiler should be off — there is no call for heat.
Turn up thermostat or aquastat. Boiler should start.
2 Check parameters 2 and 3.
To change to Parameter mode, press the MODE button one time
when in Standby mode.
Parameter 2 must be ON for DHW operation —
display
.
Parameter 3 must be ON for central heating operation —
01] on display
Refer to instructions in this guide to set parameters.
3 Check parameters 1 and 3.
To change to Parameter mode, press the MODE button one time
when in Standby mode.
If parameter 1 shows 68:
Press "+" until display returns to 140.
Then press "Store."
Display will blink when setting is accepted and stored.
If parameter 3 shows 00:
Press "+" and display will return to "01"
Then press "Store."
Display will blink when setting is accepted and stored.
If problem persists, replace the control module.
From Standby mode, press "Mode" twice and display will change
4
to "Info"
Press "Step" until display shows #6.
If #6 value displays as 32, replace the blower assembly.
Check thermostat or aquastat:
5
Turn off power to the boiler.
Install a temporary jumper on low voltage terminal strip termi-
nals 5 and 6 for central and terminals 3 and 4 for DHW.
Retry. If boiler operates, check the thermostat or aquastat and
connect wiring. Replace if necessary.
Remove jumper and retry.
6 Check boiler wiring:
Turn off power to the boiler.
Check wiring against wiring diagram. Verify all wiring is in good
condition and securely fastened.
Replace harness if necessary and retry.
7 If boiler still does not fire, replace the control module.
1 The outdoor sensor has failed or the wires are shorted. Replace the
outdoor sensor if wiring is ok.
Also, remove the outdoor sensor wires and check operation to ensure
no other problem is occurring.
Instructions in this supplement are based
on factory default parameter settings.
.
[2 01] on
[3
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