Filter
Top Products
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.
To test operation of Unitherm Governor, place in hot water
and watch for movement against spring. If no movement,
replace.
MAINTENANCE AND CARE
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.
26
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.