Bosch GWH C 920 ES Instruction Manual page 23

Minimum
3"
Fig. 23 Gas connection
Once connections are made, check for gas leaks at all
joints. Apply some gas leak detection solution to all gas
fittings. Bubbles are a sign of a leak. A combustible gas
detector may also be used to detect for leaks.
Danger: If you have a leak, shut off the
gas. Tighten appropriate fittings to stop
leak. Turn the gas on and check again
with a gas leak detection solution.
Never test for gas leaks using a match
or flame.
GAS LINE SIZING
The gas supply piping for a single heater should be
sized for a maximum draw of 225,000 BTUH. Measure
the length of gas supply line from the building's gas
main to the heater and use the tables in Fig. 25, page
24 or the gas line manufacturer's sizing tables to
determine the pipe diameter necessary. If there are
more gas appliances on the line, size the gas line
according to the total maximum amount of BTU input
rating of all appliances combined.
Note: Undersizing the gas line may result in diminished
hot water flow rate and temperature. See chapter 3.13,
page 29 for the procedure to measure gas pressure.
Proper gas pressure must be confirmed at time of
installation.
6 720 608 836
Gas supply
Cap
Gas piping
Fig. 24
Installation instructions
Inlet gas particle screen
(included)
23