Bosch 830ESNG User Manual

Installation Instructions

Warning: This kit shall be installed by a qualified

service agency in accordance with these
instructions and all applicable codes and
requirements of the authorities having jurisdiction.

Gas Conversion Kit

For models: 250 SX, 250 SXO, GWH 2400 E, GWH 2400 EO, GWH 635 ES,
GWH 635 ESO, GWH 715ES, GWH 2700 ES, GWH 2400 ES, Evolution 500,
830ES, 940ES, 940ESO

Part. no 8 719 002 176

6 720 607 679 (2009/05) US

Gas Type Conversion

i

2 SCREWS

TO REMOVE

1 Gas Type Conversion

For models: 250SX, 250SXO, GWH 635 ES, GWH

635 ESO, GWH 2400 E, GWH 2400 EO only

LP AND NG ARE EXTEMELY
FLAMMABLE SO TAKE EXTRA
PRECAUTIONS WHEN
PERFORMING ANY WORK TO THE
HEATER.

PROCEDURE MUST BE
PERFORMED BY A LICENSED GAS
TECHNICIAN.

A. Preparation

B 1. Tools needed:

– flat and Phillips screwdrivers
– #40 Torx driver
– digital combustion analyzer

Fig. 2

B 7. Remove yellow painted # 40 Torx cover from the

front of the gas valve revealing a plastic #40 Torx
screw (Fig. 3).

B 2. Turn power switch to off position and unplug water

heater.

B 3. Remove cover.
B 4. Remove control board access cover (Fig. 1).

Fig. 1

Fig. 3

B 5. Remove lower wire harness from control board.
B 6. Loosen yellow painted Philips screw and cover

should rotate down revealing a brass slotted screw
(Fig. 2).

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B. Converting from LPG to NG

6720607679-11.1AL

B 1. Add jumper to location JP6 on the control board

(Fig. 4).

Fig. 4

Gas Type Conversion

B 2. Turn slotted brass screw 3.5 turns counter

clockwise (Fig. 2).

B 3. Turn #40 plastic torx screw 1 tooth clockwise

(Fig. 3).

B 4. Adjust CO2 (see chapter 2).

C. Converting from NG to LPG

B 1. remove jumper from location JP6 on the control

board (Fig. 4).

B 2. Turn slotted brass screw 3.5 turns clockwise

(Fig. 2).

B 3. Turn #40 plastic torx screw 1 tooth counter

clockwise (Fig. 3).

B 4. Adjust CO2 (see chapter 2).

D. Clean up

B 1. Reinstall yellow painted #40 Torx cover on the

front of gas valve (Fig. 3).

B 2. Rotate brass slotted screw cover up and tighten

yellow painted Philips screw (Fig. 2).

B 3. Reinstall lower wire harness onto control board.
B 4. Reinstall control board access cover (Fig. 1).
B 5. Apply conversion sticker to right side panel above

rating plate. Ensure information is filled out
accurately.

B 6. Reinstall cover and return to service.

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3

Measuring and adjusting CO2 levels

2 Measuring and adjusting CO2 levels

The CO2 can only be adjusted by a certified gas
technician with a calibrated CO2 analyzer.

Caution: One factor that may affect

CO2 levels is improper gas pressure.
Please see Chapter 2.12 of manual for
the procedure to measure gas pressure
and record your findings below:

Static Gas Pressure: " WC

P1 Operating Pressure: " WC

The P1 minimum operating pressure is 5" WC for
Natural Gas and 11"WC for Propane. Do not proceed
in adjusting CO2 until pressure is at or above these
levels, but not to exceed 14” WC.

A. Once Pressure is adequate

B Turn ON/OFF switch to the OFF (O) position.
B Remove brass flat head screw on the exhaust collar,

see Fig. 5.

B Insert CO2 analyzer probe into the measuring port.

Avoid air gaps between probe and measuring port.
The tip of the probe should be in the center of the flue
pipe (approx 1.5" inserted).

B. Measuring CO2 (Cover Installed):

B Open hot water taps to achieve a flow rate of at least

4 gallons per minute. (1 tub and 2 sinks should be
sufficient).

B Record the CO2 reading in P2 below. (Analyzer read-

ing may take several minutes to stabilize).

B Press the ‘+’ button until P1 appears. Unit will ramp

up to high fire and the water flow should increase.

B Record the CO2 reading in P1 below.

P2 CO2 Reading: % CO

P1 CO2 Reading: % CO

2

2

Compare your readings to those found in table 1 under
the “With Front Cover” column. If CO2 readings are off
make adjustments as outlined below.

Note: The “Without Front Cover” column give
approximate values with the cover off to ease the
adjustment process. Final readings should be taken
with the cover on.

C. Adjusting CO2:
Note: P1 adjustment will change the P2 reading.

Confirm the P1 value BEFORE adjusting the P2 level.

1. P1 CO2 level adjustment:
B Loosen yellow painted Philips screw (1) and rotate

cover down (2) revealing a brass slotted screw.
Fig. 7.

B Adjusting the slotted screw counter clockwise will

raise P1 CO2 levels and clockwise will lower P1
CO2 levels. Adjustments to the slotted screw will
also change P2 CO2 levels.

Fig. 5

B While holding in the Program (P) button, turn the

ON/OFF switch to ON (I) position (see Fig. 6). As
soon as ‘188’ flashes on the display, release the
Program button. The display should now read P2.

Fig. 6

4

2. P2 CO2 level adjustment:
B Remove yellow painted #40 Torx cover from the front

of the gas valve. (Fig. 8) A plastic #40 Torx screw will
be revealed.

B Adjusting the plastic #40 Torx screw counter clock-

wise will lower P2 CO2 levels and clockwise will
raise P2 CO2 levels.

Note: This screw adjustment is very sensitive and may
take several minutes to stabilize.

3. Verify both P1 and P2 are within the ranges specified
in table 1 under the “With Front Cover” column. Repeat
steps 1 and 2 as necesssary until CO2 values are within
the specified ranges.

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