X. Service Instructions
DANGER
This boiler uses flammable gas, high voltage electricity, moving parts, and very hot water under high pressure. Assure that all gas and electric power supplies are off and that the water temperature is cool before attempting any disassembly or service.
Assure that all gas valves and electrical disconnect switches are off before attempting any disassembly or service.
Do not attempt any service work if gas is present in the air in the vicinity of the boiler. Never modify, remove or tamper with any control device.
WARNING
This boiler must only be serviced and repaired by skilled and experienced service technicians.
If any controls are replaced, they must be replaced with identical models.
Read, understand and follow all the instructions and warnings contained in all the sections of this manual.
If any electrical wires are disconnected during service, clearly label the wires and assure that the wires are reconnected properly.
Never jump out or bypass any safety or operating control or component of this boiler.
Read, understand and follow all the instructions and warnings contained in ALL of the component instruction manuals.
Assure that all safety and operating controls and components are operating properly before placing the boiler back in service.
A.General. Inspection and service should be conducted annually, except as noted. Turn off electrical power and gas supply while conducting service or maintenance. Follow instructions TO TURN OFF GAS TO APPLIANCE. See Figures 48, 49, 50 or 51.
B.Maintenance of Low Water Cutoff
1.McDonnell & Miller
a.Drain boiler to point below Tapping 'K'. See Figure 2.
b.Disconnect wire(s) connecting control and probe.
c.Remove control from probe.
DANGER
Assure that the boiler is at zero pressure before removing the LWCO probe. Do not rely on the pressure gauge to indicate that the boiler is at zero pressure. Open the safety valve to relieve all internal pressure prior to proceeding. Safety valve discharge piping must be piped such that the potential for burns is eliminated.
d.Unscrew probe from Tapping 'K'. Inspect for scale and sediment buildup.
e.Remove light deposits with damp cloth soaked with vinegar.
f.Remove stubborn deposits using diluted phosphoric acid (H2PO4) solution, 3 parts water to 1 part phosphoric acid. Normal operation will occur with up to 0.2 inch of contamination. If scale or contamination exceeds 0.2 inches, clean probe more frequently.
g.Clean Tapping 'K' to remove old pipe dope and other foreign matter.
h.Apply moderate amount of good quality pipe dope to probe threads, leaving two end threads bare. Install probe in Tapping 'K'. Mount control on probe. Attach wire(s) between control and probe.
i.Fill boiler to normal waterline. Add water treatment as needed.
2.McDonnell & Miller 67 Float Style Only.
a.Weekly (or more frequently if necessary). Open
b.Annually. Dismantle to extent necessary to remove obstructions and insure proper function of working parts.
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