Reznor HRPD (Outdoor Duct Furnaces) Unit Installation Manual - Manual (Page 27)

Form I-RP/HRPD, P/N 132210 R14, Page 27
10.2.4 Clean the Heat
Exchanger
To clean the outer surfaces (circulating air side) of the heat exchanger, gain access
by removing the inspection panels in the ductwork or remove the ductwork. There are
baffles between the heat exchanger tubes as shown in FIGURE 20. (NOTE: If the
heater has been converted to high CFM (see APPENDIX, page 29, and Label on the
unit), these baffles will have already been removed.)
To clean the outside of the tubes and the baffles, remove each baffle individually. To
remove the baffles, remove the screws marked "A" in FIGURE 20, and slide each
baffle forward. Use a brush and/or an air hose to remove accumulated dust and grease
deposits from the heat exchanger tubes and the baffles. Re-install the baffles by sliding
them into the rear slot and replacing the screw.
The inner surfaces (combustion air side) of the heat exchanger can be reached for
cleaning with the burner rack removed. (See Paragraph 10.2.2.) An air hose, an 18-24"
long, 1/2" diameter furnace brush (or heavy wire with steel wool securely attached),
a flashlight, and a mirror are needed. Furnaces designed to provide high efficiency
heating have "V" shaped baffles in the top of each heat exchanger tube. Follow the
instructions below to remove the "V" baffles when cleaning the inner surfaces of the
heat exchanger.
NOTE: High efficiency furnaces manufactured prior to 3/95 have a "C" prefix in their
model designation. All furnaces manufactured beginning 3/95 are designed for
high efficiency and include the heat exchanger "V" baffles.
Instructions to Remove Heat Exchanger "V" Baffles:
1) Remove the ends of the flue gas collection box. On the control side of the
furnace, remove the venter assembly and the flue outlet duct to gain access to the
collection box end.
2) Sizes 125-300 -- Remove one of the tube baffle retaining angles on each inside
wall of the collection box. Each tube baffle angle has one screw.
Size 400 -- Remove the inner baffle from the flue collection box. On the control
side, align the inner baffle with the slot in the collection box edge. Pull the inner
baffle until it clears the heat exchanger. Remove the screw at each end and slide
the flue diverter out of the furnace.
3) Pull the "V" baffles out of the heat exchanger.
Clean the inner surfaces of the heat exchanger from beneath using the brush to "scrub"
the tube walls to remove any accumulated dust, rust and/or soot. Clean the "V" tubes
and re-assemble the heat exchanger and the furnace. Check the furnace for proper
operation.
FIGURE 21 - Remove "V" Baffles to Clean
Inner Surface of Heat Exchanger Tubes
Loosen
Screws
Remove
Screws
Tube Baffle Holddown Plate Rear Baffle
Front
Baffle
Tube
Baffle
Top Baffle
Support
Screws
B
Bottom
Baffle Support
Bracket
s
Air Discharge
Direction of
Airflow
Screw C
Right
Lef
t
Screws A
Screw C
Airflow
Baffles
FIGURE 20 -
When cleaning
outer heat
exchanger
surface remove
directional air
baffles. Remove
Screws "A" and
slide baffles
out. Clean and
replace all
baffles.