Bosch CWH 1000 P Service Bulletin Booklet Download

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WARNIN

ARNIN

ARNING

LP & N

LP & NG ARE EXTREMEL

G ARE EXTREMEL

G ARE EXTREMELY FL

Y FL

Y FLAMMABLE SO

AMMABLE SO

TTTTTAKE EXTRA PRECA

AKE EXTRA PRECA

AKE EXTRA PRECAUTIONS WHEN

UTIONS WHEN

PERF

PERFORMIN

ORMIN

ORMIN G ANY W

G ANY W

G ANY WORK T

ORK T

ORK TO THE HEA

O THE HEA

O THE HEATER

TER

CT-22

page 1 of 1

rev 08/06

Bosch Water Heating

340 Mad River Park, Waitsfield, VT 05673

BBT

NORTH AMERICA CORPORATION

Bosch Group

CLEANING AND REPLACING PILOT

ASSEMBLY

MODELS:

1000P, 1600P, 1600H
260PN, 425PN, 425HN

For 1000P, 1600P, 260PN, 425PN models:
Removing pilot tube and orifice

1. Shut off gas to heater and remove cover per installation

manual.

2. Remove wire clip holding upper end of pilot tube into

burner bracket. (Fig. 1)

3. Remove lower end of pilot tube from black clip on gas

valve being careful not to damage cylindrical air screen

4. Lift up pilot tube and remove from bracket

Cleaning pilot tube and orifice

1. Blow out pilot tube and air screen.

2. Remove brass hex-headed pilot orifice from gas valve

with 8mm wrench. Black clip may have to be removed

with pliers to access orifice with socket wrench

3. Clean orifice with compressed air or aerosol carburetor

cleaner. (NOTE: Do not ream or poke any object through

orifice opening).

Reinstalling pilot tube and orifice

1. Screw clean or new orifice into gas valve and tighten

with 8mm wrench. Do not over tighten.

2. Place cylindrical air screen over pilot orifice. Angle top

of air screen outwards.

3. Feed bottom of pilot tube into angled cylindrical air

screen. Push bottom of pilot tube with air screen into

black clip until it snaps into place. NOTE: Air screen

may become deformed during this process. Simply mold

back into cylindrical shape by hand.

4. Replace cover, open gas supply and return heater to

service.

6. If pilot flame is not strong and blue, replace orifice (NG

is stamped 4C, LP is stamped 3C).

For 1600H, 425HN models:
Removing pilot assembly and orifice:

1. Shut off gas to heater and remove cover per installation

manual.

2. Remove 2 philips head screws holding pilot shield and

pilot assembly to front of burner. Remove pilot shield.

3. Remove pilot assembly from burners (with spark elec-

trode and flame sensor) being careful not to damage

cylindrical air screen on bottom.

Cleaning pilot tube and orifice

1. Blow out pilot tube and air screen.

2. Remove brass hex-headed pilot orifice from top of pilot

electrovalve with 8mm wrench.

3. Clean orifice with compressed air or aerosol carburetor

cleaner. (NOTE: Do not ream or poke any object through

orifice opening).

Reinstalling pilot assembly and orifice:

1. Screw clean or new orifice into pilot electrovalve and

tighten with 8mm wrench. Do not over tighten.

2. Insert pilot assembly into burner and fit cylindrical air

screen onto orifice and pilot tube.

3. Insert screws through pilot shield and pilot assembly

into burner and tighten.

5. Replace cover, open gas supply and return heater to

service.

6. If pilot flame is not strong and blue, replace orifice (NG

is stamped 2C, LP is stamped 1C).

FIGURE 2

Pilot shield

Pilot bracket
screws

Burners

Pilot air
screen

1600H, 425HN pilot assembly

1000P, 1600P, 260PN, 425PN pilot assembly

FIGURE 1

Pilot air screen

Pilot wire clip

Burners

Pilot tube

Thermocouple
lead

Pilot orifice

Summary of Contents for CWH 1000 P

Page 1: ...Service Bulletin Booklet For Compact model water heaters GWH 260 PN GWH 425 PN GWH 425 HN GWH 1000 P GWH 1600 P GWH 1600 H ...

Page 2: ...8 Have a licensed gas technician verify the proper operation of the thermocouple To test the thermocouple disconnect wire from the thermocouple where it connects to the upper ECO located top right side of the heat exchanger Insert a multi meter probe into the thermocouple lead and attach or hold the other probe to the metal chassis of the heater DC com mon Light the pilot flame and hold button whi...

Page 3: ...tankless unit and hold a recently extinguished match candle or any other visible smoke source in front of the triangular open ing on the draft diverter 4 The smoke should be sucked quickly into the opening and up the exhaust vent If the smoke is blown back a negative air situation exists and must be corrected See the combustion air section in the manual or bulletin CT 05 Negative air and freeze pr...

Page 4: ...gas supply back on 2 Operate all other gas appliances at maximum output 3 Record static pressure reading in Table 1 4 Leave manometer connected to inlet tap for operating pres sure test C Operating pressure test 1 Light pilot if neccessary 1000P 1600P 260PN and 425PN models 2 All other gas appliances should still be running at full ca pacity 3 Set heater to maximum output 1000P 1600P 260PN 425PN S...

Page 5: ...n acceptable means of supplying themselves Thus freezing cold air is pulled down the water heater s flue drawn over the copper heat exchanger potentially freezing it and the water valve below Because when idle the water heater holds only cold water freezing can happen quickly possibly causing leaks or ruptures in the heat exchanger and or the water valve The water heater does not pull air through ...

Page 6: ...aning inlet filter for more detailed instructions Check for plumbing crossover A plumbing crossover can be caused by a failed cartridge at a single lever faucet incorrect plumbing or a faulty mixing valve in the piping The crossover will create a back pressure on the water heater and prevent an adequate flow of water through it Close installer supplied cold water shut off valve to the heater if no...

Page 7: ...eased water flow helps to lower the outlet tempera ture and ensures that the heater stays activated espe cially when mixing cold water at the outlet 1 Increase the flow by cleaning the inlet filter screen in the heater Fig 1 Consult bulletin CT 12 Cleaning in let filter for more detailed instructions on removing the inlet filter 2 Increase the flow at all outlets For sinks remove fau cet aerator s...

Page 8: ...ter fitting on the water heater 6 Using another line B connect to the water outlet fitting on the water heater Route the other end of this line into a descaling reservoir 7 Using a 3rd line C from the descaling reservoir connect to the inlet side of circulating pump Verify there is a filter on the end of the line in the descaling reservoir 8 Make sure all connections are hand tight 9 Fill tank wit...

Page 9: ...s likely to experience freezing temperatures less then 32º F all water must be drained from the heater Damage as a result of improper drainage will not be covered under warranty Draining the heater 1 Shut off gas to heater 2 Shut off water supply to the heater using installer sup plied cold water isolation valve If none installed in stall before proceeding 3 Open lowest hot water faucet to drain l...

Page 10: ...1 of 1 rev 10 06 Bosch Water Heating 340 Mad River Park Waitsfield VT 05673 BBT NORTH AMERICA CORPORATION Bosch Group CLEANING INLET FILTER MODELS 1000P 1600P 1600H 260PN 425PN 425HN Removing water filter 1 Shut off the installer supplied cold water isolation valve to the heater If one is not installed install before proceeding 2 Open the nearest hot water tap to drain the plumb ing lines 3 Positi...

Page 11: ... to release from black clip on gas valve Be sure to catch air screen attached to base of pilot tube 4 Pull upwards on upper end of pilot tube to release from bracket 5 Remove black clip from bracket to release spark elec trode 6 Gently press down on top of thermocouple to release it from bracket FIGURE 3 FIGURE 4 Model 1600H 425HN Fig 2 1 Shut off gas and water to heater then remove front cover 2 ...

Page 12: ...ert thermocouple and snap into place Thermo couple tip should sit 1 4 above the burner bed 2 Put spark electrode into place and attach with clip 3 Slide upper end of pilot tube into bracket on burner assembly and reinsert pin 4 Slide base of pilot tube to the right into clip Ensure pilot air screen is installed between pilot tube and pi lot orifice Models 1600H 425HN 1 Slide pilot air screen over ...

Page 13: ... to lock up and stop delivering gas to heater This is the method for unlocking the maxitrol regulator N N N N No o o o ot t t t te e e e e This procedure should only be performed by a licensed gas technician 1 Shut off main gas supply to heater 2 Locate Maxitrol regulator at bottom of water heater 3 Confirm that the arrow on the back of the regulator is pointing up towards the heater and in the sa...

Page 14: ...water connections to water heater 6 Remove the retaining clip Fig 1 Num 1 from the threaded bushing Then remove the threaded bushing Fig 1 Num 2 from the water valve 7 Contents of heater and water lines will drain to bucket below 8 Once all water has drained reinsert threaded bushing into water valve and secure with retaining clip 9 Locate and remove clips on both left and right side connections o...

Page 15: ...drical air screen over pilot orifice Angle top of air screen outwards 3 Feed bottom of pilot tube into angled cylindrical air screen Push bottom of pilot tube with air screen into black clip until it snaps into place NOTE Air screen may become deformed during this process Simply mold back into cylindrical shape by hand 4 Replace cover open gas supply and return heater to service 6 If pilot flame i...

Page 16: ...s valve by loosening 2 set screws from underneath Fig 1 Do not loosen 3 larger screws holding plate onto bottom of gas valve or 1 screw holding on microswitch Remove water valve from heater If set screws do not unscrew easily do not force them as the gas valve may be damaged Try a descaling solution white vinegar CLR or other descaling solution on screw threads Let sit for 1 hour try again to remo...

Page 17: ... 11 3 Now tighten set screws fully and evenly 4 Lubricate O ring on pipe to heat exchanger put into water valve and secure with retaining clip from top 5 Reconnect cold water inlet flex pipe with washer FIGURE 3 F Testing operation Important Before firing the heater run water through heater to check for leaks and purge air 1 Replace and tighten cover and reinstall knob s 2 1000P 1600P 260PN 425PN ...

Page 18: ...cate the lower ECO on the copper pipe exiting the bottom left side of the heat exchanger See Fig 1 3 Using pliers disconnect both spade connections to the ECO 4 Using a 22mm or adjustable wrench unscrew the ECO from the copper pipe Be careful not to overstrain the copper pipe 5 Install new ECO and reconnect wires from electromag net and flue gas sensor Wire orientation polarity does not matter whe...

Page 19: ...omagnet 1 Turn off gas to the water heater 2 Turn off water supply to the water heater using installer supplied cold water isolation valve 3 Remove front cover of water heater as per instructions in the installation manual 4 Using 8mm or adjustable wrench loosen and remove 8mm nut and lead wire connected to electromagnet 5 Using 17mm or adjustable wrench loosen larger 17mm nut and remove electroma...

Page 20: ...o valve green is responsible for the burners 3 Using pliers disconnect wire at spade connection on electro valve needing replacement 4 Remove the two Philips head screws on each side of the Electrovalve 5 Remove the electro valve from the gas valve housing Be careful not to misplace the rubber o ring that seals the electro valve to the gas valve If a new o ring is provided with new electro valve d...

Page 21: ...single ignition wire connection to spark electrode from upper left corner of ignition unit Unclip wire from bracket on top of ignition unit 425HN models only See Fig 1 4 Remove multiple wire connector from lower right corner of ignition unit by gently pulling outwards with needle nosed pliers See Fig 1 5 Remove screw with ground wire connection from upper right corner of ignition unit Metal bracke...

Page 22: ... the upper temperature limiter ECO Fig 3 8 Remove Philips head screw attaching the flue gas sen sor to the draft hood Fig 3 9 Remove thermocouple flue gas sensor with wires from heater Installing thermocouple and flue sensor N N N N No o o o ot t t t te e e e e Replacement parts will come as two separate parts Attach the thermocouple to the safety circuit wiring with the quick connect plug before ...

Page 23: ...BBT North America Corporation Bosch Group Bosch Water Heating 340 Mad River Park Waitsfield VT 05673 Telephone 800 642 3111 Fax 802 496 6924 www protankless com techsupport protankless com ...

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