Raypak 336A - Manual (Page 40)

40
TUBE CLEANING PROCEDURE
Establish a regular inspection schedule, the frequency
depending on the local water conditions and the sever-
ity of service. Do not let the tubes clog up solidly.
Clean out deposits over 1/16" in thickness.
The heater may be cleaned from the return header
side, without breaking pipe connections. It is prefer-
able, however, to remove both headers for better visi-
bility through the tubes and to be sure the ground-up
lime dust does not get into the system.
Note that you do not remove the top panel or the
heater exchanger, generally.
After reaming, mount the wire brush in place of the
auger and clean out debris remaining in the tubes.
Another method is to remove the heat exchanger,
ream tubes and immerse heat exchanger in non-inhib-
ited de-scale solvent for severe scale build-up.
DESOOTING PROCEDURE
Soot will clog areas between fins and cause eventual
tube failure. Any sign of soot at the base of the burn-
ers or around the outer jacket indicates a need for
cleaning.
1. Remove top and flue collector from cabinet.
2. Remove "V" baffles from heat exchanger.
3. Remove burner tray. (See pg. 38).
4. Remove heat exchanger from the heater and wash
with a garden hose, making sure soot is removed
from spaces between fins.
5. 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 first have
removed the heat exchanger.
REFRACTORY PANELS - TOP VIEW
Extension Pieces (2) Auger with Carbide Tip Wire Brush
Fig.# 8154.0
WARNING: SOOT IS COMBUSTIBLE. EXERCISE
EXTREME CARE.
IMMERSION WELL REPLACEMENT
(Millivolt and ASME)
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.
Well Assembly
Fig. #2010
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.
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.
Retainer Plug
U.G.
Spring
Gasket
Fig. #2011
To test the operation of the Unitherm Governor, place
in hot water (over 110°F) and watch for movement
against spring. If there is no movement, replace unit.
Atmospheric Heaters Low NOx Heaters