Heat Transfer MODCON VWH 300 HL, Installation & Maintenance

Page: 42 / 80

PART 7: GAS PIPING
(CONTINUED)
E. DUNGS GAS VALVE
THIS SCREW WITHOUT A COMBUSTION
GAS OUTLET
VALVE
GAS SHUT-OFF
OFFSET ADJUSMENT
GAS OUTLET
CAUTION: DO NOT REMOVE THIS SCREW
PRESSURE TAP
ANALYZER
OR ATTEMPT TO MAKE ANY ADJUSTMENT TO
PRESSURE TAP
GAS INLET
GAS VALVE
GAS INLET
A
SCALE 2 : 3
DETAIL A
THROTTLE ADJUSTER
NOTE: IF FOR ANY REASON THE THROTTLE
NEEDS TO BE ADJUSTED, IT IS VERY IMPORTANT
THAT A "COMBUSTION ANALYZER" BE USED TO
ENSURE SAFE AND PROPER OPERATION.
TURN THE ADJUSTER TO THE (+) TO INCREASE
THE GAS OR (-) TO DECREASE THE GAS SUPPLY.
THIS ADJUSTMENT COULD AFFECT CO/CO%
LEVELS. MAKE SURE THE LEVELS CORRESPOND
TO THE CHART IN COMBUSTION SETTINGS.
(FIG. 10-1)
Fig. 7-2
LP-205-AA Rev. 6/3/08
MOD CON 300 GAS VALVE
tor is used, it must be a minimum of 10 feet from
the Mod Con. It is very important that the gas
line is properly purged by the gas supplier or
utility. Failure to properly purge the lines or
improper line sizing, will result in ignition fail-
ure.
This problem is especially noticeable in
NEW LP installations and also in empty tank sit-
uations. This can also occur when a utility com-
pany shuts off service to an area to provide
maintenance to their lines. This gas valve must
not be replaced with a conventional gas valve
under any circumstances.
GAS-FIRED HOT WATER SUPPLY BOILER
Boiler Manual
41