NavieN NCB300 Condensing Combi Boiler User Manual

: June 13, 2024
: Navien

Table of Contents

NavieN NCB300 Condensing Combi Boiler
Product Information
Product Usage Instructions
Safety Information
About the Boiler
Operating the Boiler
Troubleshooting
Warranty
ErP Information
References
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NavieN NCB300 Condensing Combi Boiler

Product Information

The Condensing Combi Boiler is a versatile heating appliance designed for use with natural gas or LPG (Liquid Petroleum Gas). The boiler includes an LPG conversion kit for easy installation. It is manufactured by Navien LTD and comes in multiple models: NCB300-28K, NCB300-37K, and NCB300-41K. The boiler is equipped with an ignition device that automatically lights the burner, eliminating the need for manual lighting.

Product Usage Instructions

Safety Information
Ensure to read and follow all safety instructions provided in the manual to prevent unsafe operating conditions, fire, explosion, property damage, or personal injury. Keep the manual for future reference.

About the Boiler
Description of the Boiler:
Get familiar with the features and functions of the boiler as described in this section of the manual.

Parts of the Boiler:
Understand the components and parts of the boiler to facilitate maintenance or troubleshooting.

Using the Front Panel:
Learn how to navigate and operate the boiler using the front panel controls.

Operating the Boiler
Turning the Boiler On or Off:
Follow the instructions to safely turn on or off the boiler.

Adjusting the Temperature:
Learn how to adjust the temperature settings of the boiler according to your requirements.

Resetting the Boiler:
If necessary, reset the boiler using the provided instructions.

Setting the CH Heat Demand:
Understand how to set the Central Heating (CH) heat demand for optimal performance.

Troubleshooting
Solving Basic Problems:
Refer to this section for troubleshooting common issues that may arise during boiler operation.

Understanding Error Codes:
Familiarize yourself with the error codes displayed on the front panel and their corresponding solutions.

Warranty
For warranty service, always contact an official Technical Assistance Service (TAS) as mentioned in the manual.

ErP Information
This section provides information related to the Energy-related Products (ErP) Directive compliance of the boiler.

Getting Service
If your boiler requires service, you have several options for getting service:

Contact an official Technical Assistance Service (TAS) at 0844 332 2323 or go to the website (www.navien.co.uk). For warranty service, always contact an official Technical Assistance Service (TAS) first.
Contact the technician or professional who installed your boiler.
Contact a Gas Safe Registered engineer.

When contacting an official Technical Assistance Service (TAS), please have the following information available:

Model number
Serial number
Date purchased
Installation location and type
Error code, if any appears on the front panel display

Safety Information

The following safety symbols are used in this manual. Read and follow all safety instructions in this manual precisely to avoid unsafe operating conditions, fire, explosion, property damage or personal injury. Keep this manual for future reference.

DANGER
Indicates an imminently hazardous situation which, if not avoided, could result in severe injury or death.

WARNING
Indicates a potentially hazardous situation which, if not avoided, may result in injury or death.

CAUTION
Indicates a potentially hazardous situation which, if not avoided, could result in property damage.

WARNING
If you do not follow these instructions exactly, a fire or explosion may result causing property damage or personal injury.
A. This appliance does not have a pilot. It is equipped with an ignition device which automatically lights the burner. Do not try to light the burner by hand.
B. BEFORE OPERATING smell all around the appliance area for gas. Be sure to smell next to the floor because some gases are heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS

Do not try to light any appliances.
Do not touch any electric switch; do not use any phone in your building. Immediately call the National Gas Emergency Helpline on (Freephone) 0800 111999 or your gas supplier from a neighbour’s phone. Follow the instructions received.
Do not return to your home until advised to do so.

C. Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been under water.

WARNING
This appliance can be used by children aged from 8 years and above and persons with reduced physical, sensory or mental capabilities or lack of experience and knowledge if they have been given supervision or instruction concerning use of the appliance in a safe way and understand the hazards involved. Children shall not play with the appliance. Cleaning and user maintenance shall not be made by children without supervision.

DANGER
To prevent burns:

Use the lowest operating temperature setting necessary to provide comfortably hot water.
If your household has children or elderly or disabled residents, consider using a lower temperature setting.
Read all the instructions in this manual carefully before changing the temperature setting.
Feel the water before using it on children, the elderly, or the disabled.

DANGER
This boiler’s water temperature is set to 50°C at the factory for your safety and comfort. Increasing the temperature increases the risk of accidental scalding. Water temperatures at or above 52°C can cause instant scalding or severe burns. Before you decide to change the temperature setting, read the following charts carefully.

Water Temperature| Time in which a young child can suffer a full thickness (3rd degree) burn
---|---
70°C| Less than 1 second
60°C| 1 second
55°C| 10 seconds
49°C| 10 minutes
37°C| Very low scald risk

WARNING

Shut off the gas supply if the boiler is damaged.
Have your installer or plumber show you the location of the gas shut off valve and demonstrate how to close the valve. If the boiler is damaged as a result of overheating, fire, flood, or any other reason, close the manual shut off valve and do not operate the boiler again until it has been inspected by a qualified technician.
Do not store or use petrol or other flammable liquids near this boiler. Doing so may result in fire or explosion.
Do not place combustibles, such as newspapers or laundry, near the boiler or flue system.
Doing so may result in a fire.
Do not place or use hair sprays, spray paints, or any other compressed gases near the boiler or flue system, including the flue termination. Doing so may result in fire or explosion.
Do not operate the boiler with the front cover opened.
Doing so may result in fire or carbon monoxide (CO) poisoning, which may result in property damage or personal injury.
Do not operate this boiler without proper flue system.
Doing so may result in fire or carbon monoxide (CO) poisoning, which may result in property damage or personal injury. Inspect the flue termination and air intake supply annually to ensure proper operation of the boiler. Turn off and discontinue use of the boiler if any of the flue pipes, flue elbows, or intake pipes are damaged in any way, separated at a joint, or show evidence of corrosion, rusting, or melting.
Do not touch the power cord or internal components of the boiler with wet hands.
Doing so may result in electric shock.
Do not make any electrical connections before turning off the electrical power supply at service entrance panel.
Doing so may result in severe personal injury.

CAUTION

Do not attempt to repair or replace any part of the boiler, unless it is specifically recommended in this manual.
For all other service, contact an authorised technician or licensed professional. Improper adjustments, alterations, service, or maintenance may lead to property damage or personal injury, and will void your warranty.
Do not operate the boiler if you feel something is wrong with it.
Doing so may result in product damage or personal injury.
Do not allow children to operate or access the boiler.
Doing so may result in product damage or personal injury.
Do not attempt to change the DHW water temperature while the boiler is being used.
Doing so may result in personal injury.
Do not turn on the boiler unless the water and gas supplies are fully opened.
Doing so may damage the boiler.
Do not turn on the water if the cold water supply shut-off valve is closed. Doing so may damage the boiler.
Do not use this boiler for anything other than its intended purpose, as described in this manual.
Do not remove the front cover unless the power to the boiler is turned off or disconnected.
Failure to do so may result in electric shock.
When servicing the controls, label all wires prior to disconnecting them. Failure to do so may result in wiring errors, which can lead to improper or dangerous operation.
Do not use unapproved replacement or accessory parts.
Doing so may result in improper or dangerous operation and will void the manufacturer’s warranty.
Do not place anything in or around the flue terminals, such as a clothes line, that could obstruct the air flow in or out of the boiler.
This boiler has been approved for use in the UK and Ireland only. Using the boiler in any other country will void the manufacturer’s warranty.
Should overheating occur or the gas supply fail to shut off, turn off the manual gas valve to the appliance.

UKCA/EC Conformity Declaration
Navien, hereby declares that the boiler models:
NCB300-28K, NCB300-37K, NCB300-41K
to which this declaration refers, conform to and comply with the essential requirements of the following applicable European Standards and Directives.
Gas appliances: Regulation (EU) 2016/426
Standards EN15502-1, EN15502-2-1 and EN437
Boiler Efficiency: Directive 92/42/EEC Regulation (EU) No.813/2013 Standards EN15502-1, EN15502-2-1
Low voltage: Directive 2014/35/EU and
Standards EN 60335-1, EN 60335-2-102
Electro-magnetic Compatibility: Directive 2014/30/EU
Standards EN 55014
Pressure Vessels: Directive 2014/68/EU
Navien, manufactures its products using a Quality Assurance system in compliance with Standard EN-ISO 9001:2015.

The Benchmark Scheme
Benchmark places responsibilities on both manufacturers
and installers. The purpose is to ensure that customers are provided with the correct equipment for their needs, that it is installed, commissioned and serviced in accordance with the manufacturer’s instructions by competent persons and that it meets the requirements of the appropriate Building Regulations. The Benchmark Checklist can be used to demonstrate compliance with Building Regulations and should be provided to the customer for future reference.
Installers are required to carry out installation, commissioning and servicing work in accordance with the Benchmark Code
of Practice which is available from the Heating and Hotwater Industry Council who manage and promote the Scheme.
Visit www.centralheating.co.uk for more information.

Disposal of the Product
This product should be handed in at a designated collection point, e.g. by handing it in at a duly authorised reseller when purchasing a similar product, or at an authorised collection site for recycling products which contains electrical and electronic equipment (EEE) and batteries and accumulators. Because of the potentially hazardous substances that usually accompany EEE, improper handling of this type of waste could have a possible impact on the environment and human health.
Your cooperation in the proper disposal of this product will contribute to the effective usage of natural resources.
For more information on recycling this product, please contact your city office, local waste disposal facilities, official service for chemical waste or landfill site.

About the Boiler

Description of the Boiler
The Navien NCB300 boiler is available in 3 models: NCB300-28K, NCB300-37K, NCB300-41K.

The main features are as follows:

Power Interruption: When the power is restored after a power failure, the boiler will automatically start and return to normal operation. A manual reset is not required.
Freeze Protection: A sensor inside the boiler automatically detects the temperature and, if necessary, initiates a safety heating cycle to prevent internal equipment damage due to freezing temperatures.
Short-Circuit Protection: Any short-circuit occurring in the boiler’s electrical circuit immediately blows the internal glass fuses and automatically cuts off the gas supply.
Lightning Protection : Each boiler is specially grounded, both internally and externally, to protect against lightning strikes.
Carbon Monoxide Protection: The boiler is designed to maintain a safe air-to-gas ratio and combustion rate. This function is continuously monitored by the boiler’s air ratio control module.
Thermostat Control Failure: Should the thermostat fail to function properly, the boiler’s gas supply will be shut off automatically as a safeguard.
Auto Fan Detection: The rotation of the fan is automatically detected and controlled. Fan failure will stop the operation of the boiler.
Boiling Prevention: Excessive temperatures will automatically stop the boiler.

Parts of the Boiler

Front View

Bottom View

#	Description
a	Gas connection
b	DHW hot water outlet connection
c	Central heating supply connection
d	Return adapter filter
e	Central heating return connection
f	Cold water inlet connection
g	Pump drain plug
h	Condensate water outlet

Using the Front Panel
The front panel allows you to adjust the temperature and view the operating status or error codes. Remove the protective sheet from the front panel before using it.

Icons and Digital Display
The icons and digital display on the front panel provide important information required for the boiler’s operation. Refer to the following table for detailed information.

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Buttons
Using the buttons on the front panel, you can turn on or off the boiler, monitor the current operation status, and set the values required for the boiler’s operation, such as central heating and DHW supply temperatures. Refer to the following table for detailed information.

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Operating the Boiler

Turning the Boiler On or Off
To turn the boiler on or off, press the Power button .

Adjusting the Temperature
Adjusting the Central Heating Temperature

To adjust the central heating temperature:

In normal operation mode, press the menu button The CH demand icon blinks on the screen.
Press the Plus button (+ ) or the Minus button (- ) until desired temperature appears on the display. You can adjust the temperature while the display is flashing.
Once the display stops flashing, the temperature setting is stored.

Note

Take note of the original heating temperature in case you want to restore it to the default.
The default central heating supply water temperature range is 40°C (Absolute MIN) to 90°C (Absolute MAX).
The central heating temperature cannot be adjusted when the Outdoor Reset Control is used.
The central heating temperature cannot be adjusted, when the Heat Demand function is set to OpenTherm.

Adjusting the DHW Temperature

WARNING
Before adjusting the water temperature, carefully read “To prevent burns:” on page 4. Water above 52°C can cause instant scalding or severe burns.

To adjust the water temperature:

In normal operation mode, press the menu button . The DHW demand icon blinks on the screen.
Press the Plus button (+ ) or the Minus button ( -) until desired temperature appears on the display. You can adjust the temperature while the display is flashing. Once the display stops flashing, the temperature setting is stored.
Take note of the original water temperature in case you want to restore it to the default.
The default DHW temperature range is 30°C to 65°C.
The boiler will retain your settings during a power outage.
The DHW temperature cannot be adjusted, when the Heat Demand function is set to OpenTherm.

Resetting the Boiler
If an error message appears, you can try resetting the boiler to resolve the problem. To reset the boiler, press the Power button .

If resetting the boiler does not solve the problem, refer to the Troubleshooting section of this manual or contact a Technical Assistance Service.

Setting the CH Heat Demand
To set the boiler’s CH Heat Demand, press the Menu button+ and the Plus button- simultaneously for 5 seconds. “dmnd” will be displayed for 2 seconds, and CH Heat Demand setting mode will begin.

Press the ECO button (ECO). The CH Heat Demand blinks on the screen. Then, press the Plus button ( +) or the Minus button (- ) to set the CH Heat Demand. Press the ECO button ( ECO) to save the value.

Navien Thermostat
Panel
OpenTherm
CH thermostat
Switched Live

Troubleshooting

Solving Basic Problems
If you experience a problem with the boiler, refer to the following chart for possible remedies. Error codes that appear on the front panel display are explained in the following section. For minor problems, resetting the boiler may resolve the issue. To reset the boiler, press the Power button on the front panel.
If resetting the boiler and attempting the remedies suggested below do not resolve the problem, contact Navien Technical Assistance Service (TAS) or a Gas Safe Registered Engineer.

Problem	Possible Cause(s)	What to do

No water comes out when the hot water tap is opened.

|

Is the return adapter filter clean?
Is an error code displayed on the front panel?
Is the boiler frozen?

|

Ensure that the shut–off valves on the hot and cold pipes are open.
If an error code is displayed, refer to “4.2 Understanding Error Codes” on page 14.

The water from the hot water tap is cold or turns cold and stays cold.|

Is the hot water tap open wide enough draw at least 1.9 litres of water per minute (LPM) through the boiler?
Is an error code displayed on the front panel?

| If an error code is displayed, refer to “4.2 Understanding Error Codes” on page 14.
The water from the hot water tap is not hot enough.| Is the set temperature too low?|

Check the boiler’s temperature setting. Refer to “3.2 Adjusting the Temperature” on page 11.
Check for cross plumbing between the cold and hot water lines.

The water from the hot water tap is too hot.|

Is the set temperature set too high?

| Check the boiler’s temperature setting. See “3.2 Adjusting the Temperature” on page 11.
Central heating side malfunction|

Is the setting temperature too low?

| Check the boiler’s temperature setting. See “3.2 Adjusting the Temperature” on page 11.
Is there power to the system, or is the system in standby?| Make sure the power is on, and plugged into the outlet with the correct voltage. Press the Power button and raise the setting temperature. Make sure the boiler is turned on.
Is the system running for domestic hot water (DHW)?| When the unit is heating for DHW, the heating side does not work.
Is the filter on the heating side restricted?| Clean out filters that belong to the heating side.

Understanding Error Codes
When an error code appears on the front panel, refer to the following chart for a definition and possible remedy for the situation.

Item	Error Code	Description	Reset

Combustion

Controller (PCB)

Installation

If the error code is not cleared by resetting the boiler functioning (see “3.3 Resetting the Boiler”) or if it occurs repeatedly, call the nearest official Technical Assistance Service (TAS), indicating the number of the error code appearing on the front panel.

Warranty

Annual service
For Navien warranty to be valid an annual service must be carried out by a suitably qualified and Gas safe registered installer every year after installation. The cost of this annual service is not included in the guarantee.

Your Warranty Conditions
Navien undertakes to rectify any manufacturing defect that occurs within 5 years of the installation date. Please go to our website to see any additional years on the warranty.
For Navien warranty to be valid an annual service must be carried out by a suitably qualified and Gas Safe registered installer every year after installation.

Navien Warranty registration is simple. Just register the boiler on the Navien Installers Warranty App within 30 days of installation. The details of installation will be then be automatically registered within Navien Service Management System. Alternatively, please email a photo of your completed benchmark form to service@navienuk.com.
The completed Benchmark Checklist will be required in the event of any warranty work and may be required by the local Building Control Inspector.
The cost of this annual service is not included in the Warranty.
The start-up and annual service are to be carried out by a suitably qualified and Gas Safe registered installer.
Navien Warranty will be null and void in the following cases:
If the annual service by a suitably qualified and Gas Safe registered installer has not been carried out.
If the boiler has not been installed in accordance with the applicable laws and regulations for this type of appliance.
If the boiler has not been started up immediately after its installation, by a suitably qualified and Gas Safe registered installer.
Navien Smart Plus wireless thermostat comes with 2 year warranty.
Navien Smart Plus wireless thermostat has a standard 2 year manufacturer’s warranty if a suitably qualified engineer has installed the system in accordance with Navien instructions. Failures due to misuses or incorrect installation, use of non suitable power or fuel, supply with water with physical
or chemical properties causing incrustation or corrosion, incorrect handling of the appliance and, in general, for any reason beyond Navien’s control, are excluded from this guarantee. This warranty does not affect the consumer’s rights as stipulated by law.
If your Navien boiler develops a fault your first action should be to contact your installer, as his professional assessment is needed under the terms of Navien Warranty. If you are unable to contact your installer, please phone Navien Service: 0844 332 2323 or visit Navien website: www.navien.co.uk.

Suitable Use
The NCB300 boiler is designed with all the necessary safety systems. Unsuitable use of the appliance for a purpose it was not designed for entails risk of damage to the boiler or property, and even of injury to the user and other persons.
The NCB300 boiler is designed to generate heat for domestic hot water and to be connected to central heating systems. Any use other than the above will be considered unsuitable use of the boiler. In such cases the manufacturer/supplier shall not be liable for any damage caused, and the user will be liable for the damage. Correct use of the boiler includes reading the user and installation instructions and all applicable documents, and complying with the maintenance and inspection conditions.

Everyday Care
Clean the outside of the boiler with a damp cloth with a little detergent. Do not use abrasive products to clean the boiler.

Waste Recycling and Disposal
Observe the applicable national regulations and standards concerning waste disposal.

The boiler
Neither the wall-mounted boiler or its accessories are to be disposed of with the domestic waste. Ensure the appliance and its accessories, where applicable, are suitably disposed of.

Packaging
The transport packaging will be disposed of by the specialist technician who made the installation.

ErP Information

Product Fiche (EU regulation No 811/2013)

KD Navien| Unit| NCB300- 28K| NCB300- 37K| NCB300- 41K
---|---|---|---|---
Central heating : temperature application| | Medium| Medium| Medium
Water heating : the declared load profile| | XL| XL| XL
Seasonal central heating energy efficiency class| | A| A| A
Water heating energy efficiency class| | A| A| A
Rated heat output| kW| 24| 26| 26
Central heating : annual energy consumption| GJ| 7.5| 8.1| 8.1
Water heating : annual electricity consumption| kWh| 39| 36| 39
Water heating : annual fuel consumption| GJ| 18| 18| 18
Seasonal central heating energy efficiency| %| 93| 93| 93
Water heating energy efficiency| %| 84.1| 83.9| 83.1
Sound power level| dB| 52| 47| 47
Specific precautions| Read the user’s information and installation manual before the application is assembled, installed or maintained.