7. Spark plug
Water temperature thermostat
8. Control panel
Water temperature limit switch
9. Water pump
Stack temperature switch
10. Disconnect plug
11. Disconnect plug
Pump and blower motor
Figure 4-102. Heater wiring diagram.
damaged threads. Replace cracked or badly damaged
pipes and fittings. Inspect the sight glass for broken
glass or any other damage. Replace a damaged sight
Dry cleaning solvent, P-D-680 or P-D-
glass assembly. Test the tank for breaks by filling with
661, used to clean parts is potentially
water. Repair leaks by brazing.
Reverse the procedure in a.
property. Use in a well-ventilated
4-108. Water Manifold
area as the fumes are dangerous if
Avoid repeated and
(1) Drain the system.
prolonged skin contact. Do not use
(2) Remove the limit switch cover (27, fig. 4-
near open flame or excessive heat.
Flash point of solvent is 100F.-138F.
(3) Tag and remove the leads.
(4) Uncouple the lead (20 to the pump motor
b. Cleaning and Inspection. Clean the tank with a
cloth dampened in a cleaning solvent. Wash all other
(5) Remove the two lines ( and 29).
parts in a cleaning solvent and dry thoroughly. Inspect
the pipes and fittings for cracks, leaks, or