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BOSCH 330 PN User Guide and Instruction Manual

Summary

This detailed manual provides comprehensive guidance for the 330 PN Indoor Flow Modulated Water Heater, designed exclusively for heating potable water in variable flow applications using Natural or LP Gas. It guides users through everything from safe gas connection and placement requirements to proper operation, maintenance schedules, and advanced troubleshooting of common issues (e.g., pilot failure, fluctuating hot water). Essential reading material for qualified installers, service technicians, and end-users ensuring maximum operational safety and efficiency.

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Page 1 Text Content

330 PN /0 INDOOR MODEL Flow Modulated with Standing pilot Suitable for heating potable water only - Not approved for space heating purposes (Intended for variable flow applications with steady cold water inlet temperatures)

330-PN-N - for use with Natural Gas 330-PN-L - for use with Liquefied Petroleum (LP) Gas

Warning: If the information in this manual is not What to do if you smell gas followed exactly, a fire or explosion may result

Close gas valve. Open windows.

causing property damage, personal injury or death.

Do not try to light any appliance.

Do not store or use gasoline or other flammable vapor and liquids in the vicinity of this or any other Do not touch any electrical switch; do not use any appliance. phone in your building.

Immediately call your gas supplier from a neighbor’s

Improper installation, adjustment, alteration,

phone. Follow the gas supplier’s instructions.

service or maintenance can cause injury or

If you cannot reach your gas supplier, call the fire

property damage. Refer to this manual. For

department.

assistance or additional information consult a qualified installer, service agency or the gas Installation and service must be performed by a supplier. qualified installer, service agency or the gas supplier. In the Commonwealth of Massachusetts this product must be installed by a licensed plumber or gas fitter.

Upon completion of the installation, these instructions should be handed to the user of the appliance for future reference.

Page Summary Contents For BOSCH 330 PN User Guide and Instruction Manual

Page 1 330 PN /0 INDOOR MODEL Flow Modulated with Standing pilot Suitable for heating potable water only - Not approved for space heating purposes (Intended for variable flow applications with steady cold wa...
Page 2 Index Index Warning Warning 2 Appliance details 3 2.1 330 PN specifications (Technical data) 3 Warning: The heater must be isolated 2.2 Unpacking the 330 PN heater 4 from the gas supply piping system ...
Page 3 Appliance details Appliance details 2.1 330 PN specifications (Technical Dimensions data) Depth (in): 8.66” (220 mm) Approved in US/Canada Width (in): 12.20” (310 mm) Height (in): 22.83” (580 mm) Capa...
Page 4 Appliance details 2.2 Unpacking the 330 PN heater 2.3 General rules to follow for safe operation This heater is packed securely. Before installing the unit, be certain you have the 1. You should follo...
Page 5 Appliance details 2.4 Dimensions and installation clearances Fig. 3 Dimensions in Inches and (mm) Heat exchanger Burner Dimensions inches (mm) Temperature control Water valve 330 PN Gas connection Out...
Page 6 Installation instructions Installation instructions 3.1 Introduction Warning: The heater must be isolated Please follow these instructions. Failure to follow from the gas supply piping system instruct...
Page 7 Installation instructions 3.4 Mounting Heater Warning: before starting installation: check that there are no loose parts inside the appliance ensure that gas pipe, gas valve, and burner have no damage...
Page 8 Installation instructions 3.5 Combustion air requirements Fuel Gas Code for complete information. In buildings of tight construction all air should be taken from outside. The BOSCH PRO water heater ho...
Page 9 Installation instructions 3.6 Venting Keep the horizontal section short and avoid too many elbows. The maximum horizontal run allowed is half of the total vertical vent height; horizontal vent connect...
Page 10 Installation instructions Masonry chimney GAS VENT TERMINATIONS FOR LISTED VENT CAPS Masonry chimneys shall be built and installed in Roof pitch H (minimum) feet meters accordance with NFPS 211 or loc...
Page 11 Installation instructions 3.7 Gas piping & connections Attach the appliance regulator to the inlet gas pipe. The minimum diameter required for any appliance Before connecting the gas supply, check...
Page 12 Installation instructions FOR NATURAL GAS Maximum Capacity of pipe in Cubic Feet of Gas per Hour for Gas Pressure of 0.5 Psig or less and a Pressure drop of 0.3 in Water Column (0.75mbar).(Based on a ...
Page 13 Installation instructions 3.8 Measuring gas pressure or suitably rated stainless steel flex line piping be used for at least three feet before and after the heater (follow Connecting manometer local c...
Page 14 Operation instructions 3.10 Recirculation application Operation instructions Since recirculation through the heater is not permissible, the following drawing is provided to outline 4.1 For your safety...
Page 15 Operation instructions 4.2 Lighting instructions With the gas valve button fully depressed, light pilot by pushing the piezo button. This step may have to STOP! Read the previous safety information. b...
Page 16 Operation instructions 4.4 Setting the water temperature The hottest position is the highest flame position all the way to the right. The 330 PN has a gas control that modulates burner input in respon...
Page 17 Maintenance and service Maintenance and service 5.1 Maintenance intervals Disconnect the water pipe leading out of water valve to the heat exchanger. Do this by removing the retaining pin on water val...
Page 18 Maintenance and service 5.4 Main burners 12. Run solution through the heat exchanger until the solution returning to the descaling reservoir comes out The main burner flames should be blue, with a mor...
Page 19 Troubleshooting Troubleshooting 6.1 Introduction 4. Pilot flame should be blue in color and completely engulfing the tip of the thermocouple. If not, have a Many of the questions customers ask regardi...
Page 20 Troubleshooting 8. If steps 1 through 7 do not correct the problem, then slide control button towards the single flame position confirm that the gas pressure is adequate. Ensure gas for lower hot wate...
Page 21 Troubleshooting temperature. This dial turns counter clockwise for lower proceed further. Contact your original installer or a local temperatures and clockwise for higher temperatures. certified gas t...
Page 22 Troubleshooting debris. Restrictions in the water path can slow water flow through the heat exchanger causing it to boil and make noise. 3. If the water has a high mineral content, the heat exchanger ...
Page 23 Protecting the environment Protecting the environment Packing The packing box may be fully recycled as confirmed by the recycling symbol . Components Many parts in the heater can be fully recycled in ...
Page 24 Interior components and diagram parts list Interior components and diagram parts list 8.1 Interior components Fig. 27 Functional scheme Heat exchanger Flexible hot outlet Burner Gas control slide Temp...
Page 25 Interior components and diagram parts list 8.2 Components diagram 6720608126-02.2 JF Fig. 28 Components Diagram
Page 26 Interior components and diagram parts list 8.3 Parts list Item Description Reference Front cover 8 705 431 413 0 Shield 8 705 506 911 0 Temp. control knob 8 702 000 295 0 Draft Diverter 8 705 505 438 ...
Page 27 Fifteen Year Limited Warranty Fifteen Year Limited Warranty General part(s). All such costs must be borne by the Purchaser. Additionally, this warranty does not cover any labor BOSCH PRO water heaters...
Page 28 Installer Checklist, to be performed by installer upon installation Serial Number ___ ___ ___ ___ ___ ___ ___ ___ (8 digit serial number is located on rating plate on right side panel) Gas Pressure Re...

Manual Details

Brand Bosch
Pages 28
File Size 2.50 MB
Published May 16, 2026
180 views

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Frequently Asked Questions

Does the unit support space heating?

No, it is suitable only for heating potable water and is not approved for space heating purposes.

What gas types can this heater operate with?

It supports Natural Gas (330-PN-N) or Liquefied Petroleum/LP Gas (330-PN-L).

What are the minimum plumbing requirements for installation?

The hot and cold water connections require a minimum size of 1/2” NPT, and the minimum recommended water pressure is 13 PSI.

How do I troubleshoot low hot water temperature or fluctuation?

Check section 6.7 (Water is too hot) and 6.8 (Water is not hot enough) in the troubleshooting guide for specific steps.