Page 27
SECTION IV: INSTALLATION (cont .)
GAS CONNECTIONS
CAUTION
Do not use this water heater with any gas other than the type listed on the rating label.
Check the rating label on the front of the water heater and make sure the gas to be
used matches the gas stated on the rating label. Consult your local gas company or
Bock Water Heaters with any questions.
A manual valve, union, and a sediment trap shall be provided in front of the gas valve. All gas
piping must conform to local codes and/or the National Fuel Gas Code ANSI 223.1/NFPA 54 or
CSA B149.1.
Note:
When sizing the gas piping to the heater, make sure that the pressure at the valve is
sufficient when all other appliances are operating. Undersized gas piping will reduce water
heater performance and life as well as result in nuisance lockouts. Also verify that the gas
service and meter are sized properly for the load.
Gas piping should be carried oversize, i.e.:
3
⁄
4
inch or 1 inch or larger for
1
⁄
2
inch valve to
within 2 feet of the valve itself. This sustains pressure at the valve during start-up to prevent
flashbacks caused by momentary pressure loss. For natural gas, 5” W.C. pressure must be
maintained upstream of the gas valve during operation. For LP gas, a minimum of 11” W.C.
must be maintained upstream of the gas valve. A
1
⁄
8
inch NPT pipe connection should be
installed upstream of the manual shut-off valve to check incoming gas pressure.
During pressure testing of the gas supply piping, close the manual gas shut-off valve to the
water heater. Test pressure shall not
exceed
1
⁄
2
PSIG (14” W.C). The gas valve is only rated for
1
⁄
2
PSIG. To test at pressure greater than
1
⁄
2
PSIG, close the manual shut-off valve and
disconnect the gas operating valve.
Turn on gas and inspect piping for leaks by “painting” each joint with a soapy water solution
and check for bubbles. Make sure that excess solution does not enter the control’s plastic
housing and all wiring remains dry.
WARNING
DO NOT use an open flame to check for leaks. Serious injury or death could result from
fire or explosion.
The pipe thread compound that is used on gas piping must be of the type resistant to
propane gas. Do not use teflon tape on gas piping.
The recommended gas piping to the water heater control is shown in Figure 16.
Figure 17 gives an overview of all field piping connections.
