25
Pilot Removal & Cleaning
(Millivolt)
1. Disconnect pilot tubing and wires from gas valve.
2. Remove pilot assembly from burner tray.
3. Remove pilot from bracket.
4. Remove pilot orifice and air opening (Honeywell
MV unit only), and clean with wire or small brush.
5. Reverse above procedure to reinstall.
Heat Exchanger Removal
1. Shut water, gas and electricity off, close valves
and relieve pressure, then remove relief valve.
Remove side inspection panels.
2. Remove top jacket holding screws. Remove the
jacket top.
3. Remove the four (4) screws holding down the flue
collector. Remove the flue collector.
4. Remove upper in/out access panel.
Pilot
Thermopile
Air Opening
Orifice
Fig. 33: Honeywell Millivolt Pilot
5. Disconnect all electrical wiring from in/out header.
6. Remove temperature sensor from in/out header.
7. Disconnect flange nuts on In/Out header.
8. Set aside heat exchanger side baffles.
9. Lift heat exchanger straight up using caution not to
damage refractory.
10. Reverse above procedure to reinstall.
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.
Use the Tube Cleaning Kit #052871F to ream the
tubes as necessary. 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.
De-sooting 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, includ-
ing side baffles.
3. Remove burner tray.
CAUTION:
Do not enlarge hole in pilot orifice.
Extension Pieces (2)
Auger with Carbide Tip
Wire Brush
Fig. 34: Tube Cleaning Kit
NOTE:
Please remove heat exchanger from heater
prior to reaming or removing debris.
CAUTION:
Soot may be combustible. Wet sooted
surfaces completely prior to cleaning. Do not use
steel wire brush.