750-211 (revised 2009)
Promethean Boilers, Model 4WI Manual
8-15
8.9 — Motorized Gas Valve
8.9 — Motorized Gas Valve
The motorized gas valve (Hydramotor) operating mechanism is
completely immersed in oil and little maintenance is required
because of the sealed design. However, proper operation should
be checked on a routine periodic basis.
Keep outer parts of the valve clean, especially the stem between
the operator and the valve. A nicked, scored or otherwise dam-
aged valve stem can cause leakage. Do not remove dust covers if
installed.
FIGURE 8-18. Motorized Gas Valves
The packing gland is of the O-ring type. If oil is noticed around the operator base or if leakage occurs, repair by
replacing any leaking O-rings and refilling the actuator with oil.
If the actuator is sluggish or fails to operate, even after the oil level is checked, replace the entire operator portion.
8.10 — Solenoid Valves
Foreign matter between the valve seat and seat disc can cause leakage. Valves are readily disassembled; however,
care must be used during disassembly to be sure that internal parts are not damaged during the removal and that
reassembly is in proper order.
A low hum or buzzing will normally be audible when the coil is energized. If the valve develops a loud buzzing or
chattering noise, check for proper voltage and clean the plunger assembly and interior plunger tube thoroughly. Do
not use any oil. Be sure that the plunger tube and solenoid are tight when reassembled. Take care not to nick, dent,
or damage the plunger tube.
Coils may be replaced without removing the valve from the line.
Check coil position and make sure that any insulating washers or retaining springs are reinstalled in proper order.
Be sure to turn off power to the valve in order to avoid electrical shock. Failure to follow these instructions could result
in serious injury or death.
!
Warning
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