The following switches are optional equipment that may be installed on boiler. These devices have indicator lights that illuminate if tripped. High gas pressure switch – Trips if there is excessive gas pressure on the outlet side of the gas valve and must be manually reset. Low gas pressure switch – Trips if there is low gas pressure on the inlet side of the gas valve and must be manually reset.
- If an indicator light is illuminated, investigate the source of the error for that particular switch.
- With boiler in service mode, measure the gas pressure in the supply line with a gas pressure meter. Monitor the gas pressure during both low and high fire conditions for correct pressure range.
- If there are no optional switches or none of the indicator lights is illuminated on the optional switches, use an ohmmeter to test each of the switches one at a time. Turn the power off to the boiler and disconnect the switch to be tested from the boiler to determine which has tripped. When you find the tripped switch investigate the cause of the fault based on the purpose of the switch.
