36
On electric boilers, the high limit thermostat is located
behind the contactor box cover. On electric boilers
with two heating elements, the thermostat is connected
to one of the heating element lugs. On electric boilers
with four heating elements, the thermostat is located
between the center pair of elements at the top of the
elements.
Steam Supply Solenoid
The magnetic coil of a solenoid valve is removed from
the valve by removing the snap catch at the center
top. Unions are provided to allow easy removal of the
valve bodies. The solenoid valves must be removed
to disassemble them.
Remove the two screws and remove the inlet part of
the body, the compression spring on the back of it and
the plastic part now exposed.
Unscrew and remove the plunger tube. Remove the
plunger (the valve blade is pinned to the lower end of
the plunger). The plastic seat at the exhaust side of
the valve blade may now be removed from the body.
This is a direct acting valve.
The blade must be clean and the blade mating surfaces
of the plastic seat members must be flat and
undamaged. The plunger and plunger tube must be
clean and the plunger must slide freely in the tube.
The compression spring which fits in the hole in the
top of the plunger must be clean and move freely.
Removing the Generator Assembly
Turn off the gas and electrical supplies and close the
water inlet valve. Drain the generator. Remove the
screws holding any control box which would obstruct
removal of the boiler through the front of the generator
base.
Disconnect the
1
⁄4” diameter water inlet tubing.
Disconnect the wire and conduit from the low water
cut-off probes, high limit thermostat, and the automatic
blow down valve (if so equipped). Uncouple the union
on the steam outlet and blow down the lines.
Remove all the screws holding the flue and flue
collector to the generator. Remove the anchor screws
holding the generator to the frame. Slide the generator
forward. The burner box, anchored only by the
generator, must be prevented from sliding forward
with the generator.
Fill Solenoid Valve
It is not necessary to remove the valve body from the
supply line to disassemble it. Remove the retaining cap
and remove coil assembly. Unscrew the stem from the
valve body. All parts are now accessible for inspection
and cleaning. Do not reuse damaged or worn parts.
Pay careful attention to proper orientation and
placement of parts during reassembly.
Water is Not Being Supplied to Boiler
Turn steamer ON. Check that water supply is available
to the steamer. If after 20 minutes no water can be
observed in the water level gauge sight glass, then
check for a problem with the water solenoid valve or
water level control float and/or probe.
The water level control probe may be covered by
scalant, thereby falsely indicating sufficient water is
present in the boiler. Detach, remove and thoroughly
clean the water level control assembly to remove scalants
and lime build-up. This condition indicates extremely
poor water quality being supplied to the boiler. Water
must be cleared up immediately with a proper water
conditioner to avoid complete breakdown of the steamer.
Water may be draining through an open boiler
blowdown solenoid valve as quickly as it is fed to the
boiler. Loose wiring or a burned out coil may prevent the
valve from closing. This valve contains a movable blade
and when closed, the blade reacts as a guillotine which
should be free to move fully down into the valve pocket
(projection at bottom of valve) so that the pierced hole
in the blade aligns perfectly with the body opening. If
debris has accumulated in the bottom of the valve
pocket, then the blade will not be able to move into the
pocket completely.
If the valve coil needs to be replaced, remove valve
from cooker body and remove retaining clip at top of
solenoid. Grasp cover and housing (green) intact
with coil inside and slide off from valve. Unscrew
projecting tube from top of valve body and remove
internal mechanism together with blade assembly.
Next, unscrew both assembly bolts and split brass
body of valve, removing loose internal parts. Flush
and clean pocket thoroughly. Reassemble all parts in
reverse order of disassembly. Energize valve with
120 volt power, and if valve fails to close, replace coil.
Reconnect all plumbing.
