Replacement Parts, Combustion Chamber Removal

Combustion Chamber Removal

To remove combustion chamber refractory you must first have removed the heat exchanger. Unbolt metal combustion chamber retainer from top and remove refractory panels individually.

9.DO NOT apply excessive torque during rolling operation and avoid thinning any wall of the tube beyond 0.015".

10.Use same procedure on opposite end.

11.Apply line pressure test. Re-roll if necessary.

12.Reinstall as outlined under HEAT EXCHANGER REASSEMBLY.

Fig. 41: Refractory Panels—Top View

Control Well Replacement

Remove top, sensing bulb and clip. Collapse well tube at the open and with a chisel, push through into head- er and remove the well through header. Insert a new well and roll into place. If a roller is not available, sol- der the well in place with silver solder.

Tube Replacement

1.Remove heat exchanger from heater following instructions outlined under HEAT EXCHANGER REMOVAL on page 45.

2.Remove in/out and return headers. Remove "V" baffle from damaged tube.

3.Remove damaged tube by cutting with a hack saw or shearing with a chisel adjacent to each tube sheet.

4.Collapse stub ends in tube sheets using a chisel or screwdriver. DO NOT cut into tube sheet or mar surface in tube hole in any way.

5.Insert replacement tube by inserting the end with the most fins removed in the opening of one tube sheet. Slide tube until the opposite end clears the other tube sheet and fit the tube into the hole.

6.Insert the tube roller into tube opening up to stop, making certain that 1/8" of tube projects beyond the tube sheet.

7.Attach drill to tube roller, holding it straight and level. Note: Use a 3/8" heavy duty, reversible, electric drill or larger. Proceed to expand tube until tool starts to grab. Approximately 1/2 to 1" of the tool shank will be visible.

8.Reverse drill motor and withdraw tube roller, If necessary wrench out by hand.

Cleaning Flue Gas

Passageways

Soot will clog areas between fins and cause eventual tube failure. Any sign of soot at base of burners or around outer jacket indicates a need for cleaning.

1.Lift off drafthood and flue collector by removing bolts and screws.

2.Remove "V" baffles from heat exchanger.

3.Remove burner tray.

4.Take garden hose and wash heat exchanger, mak- ing sure soot is removed from between fins. (Avoid excessive water against refractory).

5.Reassemble: When heater is fired, some steam will form from wet refractory. This is normal.

6.Identify and correct reason for soot formation.

NOTE: In extreme cases it may be necessary to remove the heat exchanger completely for cleaning. The simplest method is high pressure cleaning at a local car wash. DO NOT WIRE BRUSH!

CAUTION: Soot is combustible, so exercise extreme care.