LAARS Mini-Therm JVS (Sizes 50-225) - Install and Operating Manual - Manual (Page 32)

LAARS Heating Systems Page 32
9B. Electrical Troubleshooting
1. Remove the control box cover on the front of the
boiler.
2. Verify that 115 volts is reaching the boiler by
testing across the black wire and the white wire
on the transformer.
3. Verify 24 volts transformer output by placing
the meter leads on the yellow and red wires. If
24 volts is not evident, replace the transformer.
Perform the following series of tests with one
meter lead attached to the yellow wire on the
transformer.
4. Place the second lead on the “HEAT” connection
on the terminal board. Turn the wall thermostat
high enough to call for heat. If the meter fails to
register 24 volts, the thermostat or its circuit may
be defective.
5. Place the second lead on the purple wire terminal
on the hi-limit switch. If no voltage across the
switch, check for defective hi-limit, open circuit
due to excessive water temperature, or a low
temperature setting.
6. For JVH only, place the second lead on the
blue wire terminal on the fan proving switch. If
voltage is present, skip to step 8. If voltage isn’t
present, connections or the draft inducer/motor
could be defective.
7. Verify the voltage across the roll-out safety
switch.
8. If it is determined that there is voltage to the
gas valve, the pilot is lit and the pilot sensor is
properly positioned, and the thermostat is set
high enough to call for heat, the gas valve or the
pilot assembly may be defective.
9. See Section 8E for LED fault codes on
temperature controller.
Caution
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation. Verify proper
operation after servicing.
Étiquette
de mise en garde tous les fils avant le
débranchement lors de l'entretien. Les erreurs de
câblage peut causer le mauvais et dangereux.
Vérifier le fonctionnement correct après l'entretien
WARNING
Follow local regulations with respect to installation
of carbon monoxide (CO) detectors and
manufacturer’s maintenance schedule of the
boiler.
AVERTISSEMENT
Conformez-vous aux réglementations locales
pour ce qui est de l'installation de détecteur de
monoxyde de carbone (CO) et du programme de
maintenance du fabricant de la chaudière.