Gas Installation Instructions; Gas Connection; Gas Pressure; Gas/Air Ratio Control - DeDietrich 310 ECO Series Installation And Operating Manual

9.0 INSTALLATION INSTRUCTIONS FOR GAS INSTALLER

9.1 Gas connection

The Gas 310/610 is suitable for use with natural gas only. The gas connection is at the top of the boiler
(see fig. 02). The boiler is fitted with a gas filter as standard to prevent dirt from contaminating the gas
valve or burner assembly. An isolating main gas cocks must be installed in the vicinity of the boiler.

A main gas shutoff valve should be connected to the 2 Inch NPT connection on the boiler, and
must be readily accessible and within hand reach.

Sediment trap must be installed upstream of the main gas cocks shutoff valve.

The boiler fuel train does not require venting to the atmosphere, other regulators and safety
shutoff valves may require venting and relief piping to the atmosphere, consult their
documentation.
9.2 Gas pressures
The boilers main gas valve can accept a maximum inlet pressure up to ½ psi or 14 "w.c. [35 mbar], but
MUST provided with a min. of 3.5 "w.c. [8 mbar] at the gas filter inlet test point when the boiler is
operating at max output. Pressures below this level can result in lockouts (for multi gas appliance
installations this minimum pressure must be available at each boiler with all gas appliances firing on max
output).
Gas system pressure checks:

The boiler main gas cocks shutoff valve and piping must be isolated from any gas piping pressure
testing in excess of ½ psi or 14 "w.c. [35 mbar]

The boiler main gas cocks shutoff valve and piping must be isolated by closing the main gas
cocks shutoff valve during gas piping pressure testing less than ½ psi [3.5 kPa]

The boiler main gas piping and gas train must be leak tested prior to placing the boiler in
operation
9.3 Gas / air ratio control
The boiler has a pressure differential gas/air ratio control. This gas/air ratio control maintains the correct
balance of gas and air quantities to the burner at a constant level under variable loads. This ensures
clean and reliable combustion and high part load efficiency across the entire load range. Minimum airflow
is monitored before a start by an air pressure differential sensor.
De Dietrich Gas 310/610 ECO
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