GB312 Seriess
Natural Gas Condensing Boiler
Technical Specifications
Venting Guidelines
This boiler requires a flue system approved for Category IV (condensing, positive
pressure: to ANSI Z21.13/CSA4.9.) It can be direct vented horizontally or vertically.
Combustion air can be obtained from the space or via sealed combustion. Consult
your local codes for details.
Basic Water Quality Guidelines
Water hardness
❚
Fill the system with clean water from the
municipal water supply.
❚
Consult your local water department for
the level of CaCO3 (calcium carbonate) to
determine if water treatment is necessary.
❚
Do not use water from salt bedding systems
(ion exchange) used to soften water.
❚
Approved Anti-freeze (Aluminum safe)
❚
Rhomar – Rhogard (at a concentration no
more than 60% by volume).
❚
Noble Company – Noburst-AL (at a
concentration no greater than 50% by
volume).
Maintenance
❚
Follow the instructions of the approved anti-
freeze vendor. An annual visit by a qualified
service technician is recommended.
Corrosion
❚
Damage to the system can occur when
oxygen is introduced to the heating system
water. The following must be avoided for
best system operation:
• Undersized or faulty expansion vessels
• Open vented systems
• If the system can not be constructed
as a sealed system, the use of a heat
exchanger as a means of system
separation is required.
Retrofit installations
❚
Installing a dirt trap such as a wye-strainer
is required. It must be installed in the
immediate vicinity of the boiler on the return
pipe at the lowest point in the system.
Manufacturer
Flue System
Material
Heat Fab
Saf-T Vent EZ Seal
AL29-4C
Z-Flex
Z-Vent IV Special Gas Vent
AL29-4C
Metal Fab
Corr Guard
AL29-4C
Pro-Tech
Fas-N-Seal
AL29-4C
Security Chimney
CI-System
AL29-4C
Locastion
Manufacturer
System
USA
Spears
CPVC schedule 80 pipe to ASTM D1784
Canada
IPEX
System 636 CPVC
GB312 Boiler Size
Required Air Flow (CFM)
GB312/90
95
GB312/120
95
GB312/160
130
GB312/200
160
GB312/240
190
GB312/280
220
Approved Stainless Steel vent systems
CPVC Venting Systems
(Requires use of starter adapter. See Installation Manual for list of approved chimney manufacturers.)
CPVC Venting Systems
Vent and combustion air supply system installation must comply with Part 10, Venting of
Equipment of the National Fuel Gas Code, ANSI Z223.1 or CSA B.149 or other applicable local
building code regulations.
IMPORTANT:
The flue and air supply system must be designed for a
maximum pressure of 0.40 inches WC (100Pa) for the overall system (vent and combustion air
system) Vent Terminations: Approved Tee, Termination Elbow or Roof Cap for all category IV
venting systems is required.
