DeDietrich GT 123 A Installation And Maintenance Manual page 24

4.2 Boiler Venting – Category III & IV Vent Systems Typical Layouts and Requirements.
Caution & Warning:
Improperly sealed venting system could result in carbon monoxide [CO] poisoning; ensure adequate support and
fastening of system. Ensure venting can safely exhaust all flue gases outside in an effective manner. These systems must
operate under a positive vent pressure condition that is stable. Do not puncture or drill holes in any portion of the venting,
venting to be sealed according to the vent manufacturers recommended method.
Warning & Cautions for Co-Venting:
Co-venting with other appliances shall conform latest ANSI Z223.1 & CAN/CGA 149 installation codes, any
improper operation shall be corrected, the common venting shall be sized according to the appropriate tables in Part II of
the above mentioned codes.
Category III Vent Systems Requirements:
1. Flue gas temperatures above the green line shown in chart A.
2. Usage of an approved type of venting type "BH" Positive breeching pressure
3. Breeching and chimney vent sized in accordance to local national codes or by good engineering methods.
4. Vent safety device equipped on burner [MR].
5. Condensate TEE fitting supplied on the boiler breeching as close as possible and be orientated to avoid
accumulation of flue gas condensation in the boiler or venting is also used to determine the flue gas emissions.
Category IV Vent Systems Requirements:
1. Flue gas temperatures below the green line shown in chart A.
2. Usage of an approved type of venting type "BH" Positive breeching pressure
3. Breeching and chimney vent sized in accordance to national codes or by good engineering methods.
4. Vent safety device equipped on burner [MR].
5. Condensate TEE fitting supplied on the boiler breeching as close as possible and be orientated to avoid
accumulation of flue gas condensation in the boiler or venting is also used to determine the flue gas emissions.
Caution-Warning:
Flue gas condensation is very aggressive and corrosive which could lead to failure of the venting system or drains, consult local and national codes
regarding flue gas condensation disposal. The P-trap assembly must be properly filled with water to avoid escape of flue gas emissions. The flue gas
condensation may require neutralization prior to entering the drain.
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Venting
GT 120 A - GT 1200 A 09/02/08 - 94863361 - 85784009D