Cleaning Boiler Heat Exchanger; Oiled Bearing Circulators - Cadet 40-120 Installation And Service Manual

12
Maintenance

Cleaning boiler heat exchanger

For recommended materials; including brush, appropriate
extension(s), refractory cover, and detailed instructions see
Table 12B - Heat Exchanger Cleaning Kits.
1. Shut down boiler:
• Follow the "To Turn Off Gas to Appliance" instructions
for the boiler in Section 10 - Startup.
• Do not drain the boiler unless it will be exposed to
freezing temperatures. If using freeze prevention fluid
in system, do not drain.
2. Allow time for the boiler to cool to room temperature if
it has been firing.
3. Remove the bolts securing the fan to the heat exchanger
access cover. Remove the fan.
4. Remove the nuts securing the heat exchanger access cover
to the heat exchanger and set aside.
5. Remove the heat exchanger access cover, burner, and
gas/air arm assembly.
The boiler contains ceramic fiber materials.
WARNING
Use care when handling these materials per
instructions on page 67. Failure to comply
could result in severe personal injury.
6. Remove the condensate hose from the heat exchanger end.
Connect a field supplied 3/4" diameter hose to a drain pan.
Using field supplied means, cover the refractory in the back
of the combustion chamber of the heat exchanger.
7. Use a vacuum cleaner to remove any accumulation on the
boiler heating surfaces. Do not use any solvent.
8. Brush the heat exchanger while dry using a nylon bristle
brush. Caution: DO NOT use a metal brush. Re-vacuum
the heat exchanger.
9. Finish cleaning using a clean cloth dampened with warm
water. Rinse out debris with a low pressure water supply.
10. Allow the heat exchanger to thoroughly dry.
11. Remove the field supplied rear refractory cover from the
back of the combustion chamber of the heat exchanger and
reassemble.
12. Close isolation valves on piping to isolate boiler from
system. Attach a hose to the boiler drain and flush boiler
thoroughly with clean water by using purging valves to
allow water to flow through the water make-up line to the
boiler.
13. Perform start-up and check-out procedures in the Check
Flame and Combustion - Section 10 - Startup on pages 54
and 56 of this manual.
14. Reassemble the unit and restore boiler to operation.
68
Installation & Service Manual
Table 12B Heat Exchanger Cleaning Kit
Kit
Model
Number
CTN20005
40 - 100 KIT30062
MSC20083*
MSC20085
CTN20005
MSC20083*
120 KIT30063
MSC20084
MSC20086
* Do NOT use a metal brush. Only use
CAUTION
the kit provided brush or an equivalent
replacement nylon brush.
Figure 12-3 Rope Gasket - Heat Exchanger Door
ROPE
GASKET
Rope gasket is intended for sealing combustion
NOTICE
(FIG. 12-3). If damaged DO NOT reuse, the
heat exchanger door must be replaced. Consult
factory for replacement heat exchanger door
(kits WTR30015 - WTR30018).

Oiled bearing circulators

1. Check other circulators in the system. Oil any circulators
requiring oil, following circulator manufacturer's
instructions. Over-oiling will damage the circulator.
2. Replace the boiler front access cover.
Part Component
Number Description
Rear Refractory Cover
Nylon 4" Wheel Brush*
1/4" x 12" Drill Extension
Rear Refractory Cover
Nylon 4" Wheel Brush*
3mm Allen Wrench
1/4" x 24" Drill Extension
IMG00264