Heat Exchanger; Freeze Protection - IBC DC 23-84 Installation And Operating Instructions Manual

CAUTION
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.
4-2
DC SERIES COMBI BOILERS DC 23-84, DC 29-106, DC 33-124, DC 33-160

4.1.6 Heat Exchanger

During annual inspection (with the heat exchanger cover removed), examine the
heat exchanger for signs of contamination and clean if necessary. In areas of
poor gas quality or contaminated combustion air, there may be a buildup of black
plaque (typically sulfur). Other fouling agents: airborne dust, debris and volatiles.
Clean the heat exchanger surface with a stiff plastic bristle brush only.
Refer to heat exchanger cover removal instructions in Section 3.5.1 for access
to combustion chamber and heat exchanger. Note that the safety warning
regarding burner refractory on this page must be observed.
4.1.7 Pump
Check that the pump is on in normal space heating operation and that the water
Delta T is reasonable for the heating application. The pump installed in the boiler
is a 3 speed pump and is factory set to speed 3.
4.1.8 Gas Piping
Check for damage or leaks and repair as needed.
4.1.9 Control Module
•
Check that boiler operation is consistent with the steps in Section 2.7
Sequence of Operation.
•
Check that water temperature targets and setpoint are satisfactory and have
not been adversely amended.
•
Check that the domestic hot water generation is performing as expected.
Fouling of the interior of the domestic heating coil can cause poor
performance.
4.1.10 Water Heating System
•
Check water pressure and temperature. There should be no noticeable
change if boiler and system components are functioning normally. Check for
any noise in the system.
•
Check heating system water piping for damage or leaks and repair as
needed.
•
Check for 12-15 psig in normal operation, and look to ensure pressure does
not run up toward 30 psig at high temperature. If pressure rises sharply,
consider replacement of expansion tank. Check also for noise at high fire,
which may signal water quality problems.
•
Water chemistry shall be of a quality generally accepted as suitable for
hydronic applications. See Section 1.6 for details.
•
Ensure any direct "city fill" water connections are left in the closed position to
minimize exposure to leaks and flooding.

4.1.11 Freeze Protection

The boilers control will operate the boiler to protect the boiler from freezing. If the
boiler and system components are subject to possible freezing condition then a
freeze protection solution is recommended. Check freeze protection. Use only
antifreeze made specifically for hydronic systems. Inhibited propylene glycol is
recommended. Antifreeze concentration must be between 25% and 50% of the
total volume of water in the system.
INSTALLATION AND OPERATION INSTRUCTIONS