Maintenanceandcare

MODELS 926-1223

UNITHERM GOVERNOR

INLET/OUTLET HEADER

OUTLET

INLET

Fig. #8224.0

GASKET

UNITHERM GOVERNOR

WITH POWER ELEMENT

MODELS 1287-1826 (Models prior to Jan. '95)

DOUBLE EXTERNAL U.G.

MODELS 2100-4001 (Models prior to Jan. '95)

EXTERNAL U.G.

TotestoperationofUnithermGovernor,placeinhotwater and watch for movement against spring. If no movement, replace.

To be followed one month after initial start-up and then quarterly.

1.Inspect top of heater and draft-hood for soot, and open fuel gas passageways.

CAUTION: Soot may be combustible. Wet completely when cleaning.

2.Clean main burners and pilot burner of dust and lint.

3.Inspect and operate all controls and gas valve. 4.Make visual check of burner and pilot flame. Flame

pattern on main burner and pilot is indicated above. Yellow flame means restriction of air openings. Lifting or blowing flame indicates high gas pressure. Low flame means low gas pressure.

5.Clean room air intake openings to ensure adequate flow of combustion and ventilation air.

6.Remove header opposite inlet pipes when cleaning and inspect internal tubes for scale deposits. If scale does not form within first quarterly inspection, then inspect annually thereafter.

CAUTION: Combustion air must not be contaminated by corrosive chemical fumes which can damage the heater and void the warranty.

7.Keep heater air clear and free from combustible materials and other flammable and corrosive vapors and liquids.

8.Keep moving parts lubricated.

9.Manual operation of pressure/temperature relief valve at least once a year.

SPA WATER CHEMISTRY

NOTE: Chemical imbalance can cause severe damage to your heater and associated equipment. Maintain your water pH between 7.2 and 7.8, and total alkalinity between 100 and 150 ppm. If the mineral content and dissolved solids in the water become too high, scale forms inside the heat exchanger tubes, reducing heater efficiency and also damaging the heater. If the pH drops below 7.2, the heater will be severely damaged.

NOTE: Heat exchanger damage resulting from chemi- cal imbalance is not covered under the warranty.

WINTERIZATION

WINTERIZING YOUR HEATER

When heaters installed outdoors in freezing climate areas are to be shut down for the winter, please observe the following step-by-step procedure:

1.Remove the drain plug or open the drain cock located on the inlet-outlet header. On larger heaters with external Unitherm Governor(s) and piping, locate plug at low point of Governor piping, or break connec- tions and rotate inlet fittings 180° to face downward. Turn off manual main gas and main gas shut off. 2.Disconnect compression fittings on both ends of the 1/8" copper tube and allow the tube to drain. Remove the "heat exchanger inspection panels" on the right side of the heater to gain access to the fitting on the

return header. Remove return header.