3
A. Combustion air inlet
B. Flueway fitted with stainless steel turbulators
C. Primary water
D. Primary Circuit thermostat (up to 180ºF) sensing bulb
E. Burner
F. Water cooled immersed combustion chamber
G. Primary circuit drain connection
H. Corrugated stainless steel heat exchanger
J. 1 1/2” of rigid (CFC-Free) polyurethane insulation
K. Steel body containing primary water
L Primary Connections
M.Baffles (turbulators)
N. Primary connection
O. Baked enamel steel jacket
T. Domestic water
U. Safety limit thermostat (200ºF) (manual reset) (not shown)
L.W.C.O.: Low water cut-off device (not shown)
L
Cold
water
inlet
O
M
K
J
H
F
N
G
E
C
D
T
A
B
U
Hot water
outlet
Anatomy of your Combination Heater
PRE-INSTALLATION
Fig. 1: Cross section of Combination Heater
Legend
1- CODE COMPLIANCE
Combination Heater installation must con-
form to the requirements of local codes and
the authority having jurisdiction. In the
absence of these requirements:
Gas fired heaters should be installed in
accordance with National Fuel Gas Code,
ANSI Z223.1.
For installations in Canada - CGA/B149
Installation Code for Gas Burning
Equipment.
All electrical wiring, including grounding
of the heater must be in accordance with
local codes; or in the absence of local codes
with the National Electrical Code,
ANSI/NFPA 70.
The HM G-Series combination heaters are
exempted from ASME Section VIII-1-86-136.
Check with local codes for applicability.
2- VERIFYING VENTING SYSTEM
• Confirm that the venting system is of
sufficient size to handle the flue gases
of all connected equipment.
•
Check that it is clear and free of obstruc-
tions. Particular attention should be
given to replacement of oil systems.
•
Soot may have degraded the chimney
liner and/or accumulated in the chimney
liner requiring a liner replacement or
cleaning.
•
Visually inspect the venting system for
proper size and horizontal pitch.
If inspection reveals that the existing
chimney is unsafe or inadequate for the
application, it should be rebuilt to con-
form to local or national codes, lined or
relined, or provided with a new chimney
or vent sized for the application.
DANGER