Heat Exchanger Cleaning
DC / HC Series (all models)
www.ibcboiler.com
October 29, 2019
Page 2 of 2
INSTRUCTIONAL
NOTE
The heat exchanger has a
small amount of combustion
chamber insulation
(refractory), which contains
ceramic fibers.
When exposed to extremely
high temperatures, the
ceramic fibers, which contain
crystalline silica, can be
converted into cristobalite -
which is classified as a
possible human carcinogen.
Care should be taken to
avoid disturbing or damaging
the refractory. If damage
occurs, contact the factory
for directions.
Avoid breathing and contact
with skin and eyes and follow
these precautions:
1. For conditions of frequent
use or heavy exposure,
respirator protection is
required. Refer to the
“NIOSH Guide to the
Selection and Use of
Particulate Respirators
Certified under 42 CFR 84"
for selection and use of
respirators certified by
NIOSH. For the most current
information, NIOSH can be
contacted at 1-800-356-4676
or on the web at
www.cdc.gov/niosh.
2. Wear long sleeved, loose
fitting clothing, gloves and
eyes protection.
3. Assure adequate
ventilation.
4. Wash with soap and water
after contact.
5. Wash potentially
contaminated clothes
separately from other
laundry and rinse washing
machine thoroughly.
6. Discard used insulation in
an air tight plastic bag.
NIOSH stated first aid:
• Eye contact - Irrigate and
wash immediately.
• Breathing - Provide fresh
air.
CAUTION
Any evidence that the front cover can no longer mate with the heat exchanger walls means that
the either the front cover or the heat exchanger must be replaced.
11. Peel heat exchanger gasket from its groove. See Fig. 3. Carefully inspect the gasket sealing
the heat exchanger to the heat exchanger cover for damage, hardness, cracks, and or
discoloration. If damaged in any way the gasket must be replaced.
12. Clean as necessary. IBC recommends cleaning with a stiff plastic brush, such as used for
scrubbing cooking pots. See Fig. 4. Wear protective gear such as eye protectors, gloves and a
particle mask. Care should be taken to protect the bottom of the boiler cabinet: drape a small
plastic sheet to gather debris from the cleaning. It is especially important to protect the lower
gas supply line from being fouled and the controller from getting wet.
When the heat exchanger is heavily fouled (see Fig. 5), a stiffer brush, scraper or implement may
be needed.
13. In some cases chemical intervention is also necessary; for heavily fouled heat exchangers,
contact your heating wholesaler for a cleaning solution approved for use on the gas side of an
aluminum heat exchangers, such as the two-solution process available from Axiom.
14. While the heat exchanger is open, carefully inspect the heat exchanger gasket for any signs of
discolouration, cracking or brittleness. Replace the gasket at the first signs of wear, at least
every two years, and every year in the case of heavy-use units.
Also inspect the burner, burner gasket, and ignitor.
Figure 2: 6mm Hex Bolts
Figure 5: Heavily fouled HX may require stiffer brush or tool.
How to Access the Heat
Exchanger for Cleaning
continued
9. Using a ball-ended 6mm hex key,
remove all bolts from the heat
exchanger front cover and carefully
remove the front cover, complete
with the fan attached.
10. Place the heat exchanger front
cover in a safe location. Inspect its
back surface for warpage,
especially at the top corners.
Figure 3: Removing a HX gasket
15. Reassemble in reverse order, or
see section 3.5.1 for detailed
instructions. Retighten HX bolts in
a cross pattern. Soap test all gas
connections.
Figure 4: Cleaning HX with a plastic brush.
