Instructions / Assembly

35
1. Remove top and flue collector from cabinet.
2. Remove “V” baffles from heat exchanger.
3. Remove burner tray. See page 33.
4. If ProTek Shield Assy is attached to the heater,
remove ProTek Shield Assy bonding wire from heat
exchanger stud.
5. Remove heat exchanger from the heater and wash
with a garden hose, making sure soot is removed
from spaces between fins.
6. Reverse above procedure to reinstall.
NOTE: In extreme cases it may be necessary to do
steam cleaning at the local car wash. DO NOT WIRE
BRUSH.
Combustion Chamber Removal
To remove combustion chamber, you must rst have
removed the heat exchanger.
F10723
Figure 64. Refractory Panels
A
WARNING: When removing the burners or heat
exchangers, take precautions to avoid creating airborne
dust and avoid inhaling airborne bers. When cleaning
spills, use wet sweeping or High E󰀩ciency Particulate
Air (HEPA) ltered vacuum to minimize airborne dust.
Use feasible engineering controls such as local exhaust
ventilation or dust collecting systems to minimize
airborne dust. Wear appropriate personal protective
equipment including gloves, safety glasses with side
shields, and appropriate NIOSH-certied respiratory
protection, to avoid inhalation of airborne dust and
airborne ber particles.
Immersion Well Replacement (Millivolt)
1. Shut off water to heater and drain heat exchanger.
2. Remove access panel on water connection side.
3. Remove old immersion well with bushing and sleeve.
4. Install replacement well in header.
NOTE: Installation in polymer header should be hand
tight plus 1/2 turn.
F10670
Figure 65. Well AssemblyUnitherm Governor (U.G.)
Replacement
Unitherm Governor (U.G.) Replacement
1. Shut water, gas and electricity off, close valves and
relieve pressure.
2. Drain heat exchanger.
3. Remove retainer plug located next to the outlet pipe
connection on polymer header models.
4. Unsnap old U.G. to remove from retainer plug. Snap
in new U.G.
5. Reinstall retainer plug, taking care to lubricate
gasket with a non-petroleum based grease such as
AquaLube.
F10725
GASKET
UG PLUG
UNITHERM GOVERNOR
Figure 66. Unitherm Governor - Polymer
To test the operation of the Unitherm Governor - Polymer,
place in hot water (over 110°F [43°C]) and watch for
movement against spring. If there is no movement,
replace unit.
F10642-2
UG/BYPASS ASSY
UNITHERM
GOVERNOR
Figure 67. Unitherm Governor/Bypass Valve Assy – ASME
NOTE: The U.G. on bronze header models (ASME)
can only be replaced by replacing the entire Unitherm
Governor/Bypass Valve Assembly.