Intellihot iQ251D Series Deionized Wall Hung Water Heater User Guide

June 13, 2024
Intellihot

iQ251D Series Deionized Wall Hung Water Heater
User Guide

Operation

12.1 Control Panel

Intellihot iQ251D Series Deionized Wall Hung Water Heater -
Control 12.2 Turning Water Heater ON and OFF

  1. When the power cord is plugged in the Main Menu screen will automatically appear.
  2. To turn the water heater OFF, press and hold the Power button in the upper left of the screen.Intellihot iQ251D Series Deionized Wall Hung Water Heater - ON
  3. Press the Power button to turn the unit ON.Intellihot iQ251D Series Deionized Wall Hung Water Heater - button

WARNING
Turning the unit OFF does not disconnect it from the power source. Whenever working around electrical components within the water heater, turn OFF the power at its source. Touching live electrical components can cause serious injury or death.

12.3 Setting the Time

Intellihot iQ251D Series Deionized Wall Hung Water Heater -
Setting Press the Up/Down arrows to make adjustments. Press the Back button to return to the main screen.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
adjustments 12.4 Adjusting the Water Temperature
Note: The outlet water temperature is factory preset to 120°F; however, these commercial water heaters are capable of heating water to 190°F.

DANGER
Hot water temperature over 125°F (52°C) can instantly cause severe burns or death  from scalding. Children, the disabled, and the elderly are at the highest risk of being scalded. Do not leave children or the infirmed unsupervised. Check temperature of hot water before taking a shower or bath. To control water temperature to a particular faucet, temperature limiting valves can be installed by your service professional.

All water faucets must be closed before changing the temperature setting. The unit must not be operating.

  1.  Firmly press the slider and slide it to the right to increase the temperature or to the left to decrease. Firmly hold the icon until the current set point on the display reaches the desired temperature.Intellihot iQ251D Series Deionized Wall Hung Water Heater - Firmly
  2. For finer temperature adjustments, use the (+) and (–) icons.Intellihot iQ251D Series Deionized Wall Hung Water Heater - temperature
  3. Follow any prompts shown on the screen.

12.5 Security
12.5.1 Setting Passcode Protection
It is not necessary to set a passcode for the water heater to function properly. This feature is available to help prevent unauthorized access to the unit.
If a passcode is set, it must be entered prior to accessing the main screen.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
PasscodePress ON/OFF and follow the prompts.

Intellihot iQ251D Series Deionized Wall Hung Water Heater -
prompts 12.5.2 Forgot Passcode
If the unit passcode is lost or forgotten, press the “?” icon on the screen which opens the technical support screen. Call to obtain the passcode.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
Passcode 1 12.6 iNTouch
If equipped, the iNTouch icon will be active.Intellihot iQ251D Series
Deionized Wall Hung Water Heater - iNTouch 12.7 Life Screen
These screens provide a visual indication of the remaining life of various components.
Note: Parts can be ordered by contacting technical support.Intellihot
iQ251D Series Deionized Wall Hung Water Heater - Life
ScreenService recommended: Order appropriate replacement part as soon as possible. To reset life, press and hold the appropriate bar and follow the prompts.Intellihot iQ251D Series
Deionized Wall Hung Water Heater - Service RequiredService Required: Take IMMEDIATE action when this screen appears because the part life is critical. To reset life, press and hold the appropriate bar and follow the prompts.

Service Alert Reset Code
Electrode 836
Blower 2009
Time Valve (Water Valve) 721
Gas Valve 682

O-Ring
(at the HEX inlet & HEX outlet)| 310

12.8 Unit Information
This screen provides the model, software version, serial number, and a link to the contact technical support.Intellihot iQ251D Series Deionized Wall Hung
Water Heater - Service Required 1

12.9 More Screens

Intellihot iQ251D Series Deionized Wall Hung Water Heater - More
Screens 12.9.1 Wi-Fi
Intellihot Gen II water heaters are Wi-Fi capable with the  factory installed IGT-SPR0085 WI-FI module. This featurealso allows the units to be monitored and controlled from a mobile device.Intellihot iQ251D Series Deionized Wall
Hung Water Heater - Wi-FiIntellihot iQ251D Series Deionized Wall Hung Water Heater -
StatusStatus of Wi-Fi connection screen.
12.9.2 Error History

Intellihot iQ251D Series Deionized Wall Hung Water Heater - Error
History The error history screens provides an overview of the entire unit.Intellihot iQ251D Series
Deionized Wall Hung Water Heater - Error History 1 12.9.3 telliCare Service (Subscribe at Startup)
telliCare is a Wi-Fi enabled, prognostics and predictive  maintenance service for Gen II water heaters. This serviceallows water heaters to be monitored and controlled remotely via an app on a mobile device.Intellihot iQ251D Series
Deionized Wall Hung Water Heater - Service 1Tap anywhere on the screen to continue.Intellihot
iQ251D Series Deionized Wall Hung Water Heater - screenIntellihot iQ251D Series Deionized Wall Hung Water
Heater - QR Cod

If telliCare setup is skipped, register the unit by scanning the QR Code via the App.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
SubscribeSubscribe to this service by downloading the telliCare app from iTunes App Store and following the prompts on the app.

Connecting Multiple Units

13.1 General Information
Multiple units can be connected together to supply large demands of hot water.
The water heaters communicate through a cable connection between each water heater. The benefits of connecting the units are:

  • When demand for hot water is low, fewer units will operate.
  • If one unit has an error code, the others will continue to operate.
  • Changing the settings (temperature, time, etc.) on one unit changes settings on all the units.
  • It allows shut down of one unit for maintenance while the others continue to operate.

13.2 Installation Procedure

  1. Connect all the units to a gas supply pipe. Make sure the pipe is properly sized in accordance with the BTU draw and number of units being operated. Refer to “6. Gas Connection” on page 14 for additional information.
  2. Connect all the units to the power supply. Refer to “9. Electrical” on page 33 for additional information.
  3. Install the air intake inlet and exhaust gas outlet pipes. Refer to “7. Air Intake Inlet and Exhaust Gas Outlet Pipe Connections” on page 18 for additional information.
  4. Install and connect the hot water pipes. If an optional hot water storage tank is required, connect the hot water pipes to this tank. Make sure the water pipe is properly sized in accordance with the number of units being operated. Refer to “8. Water Connections” on page 28 for additional information.
  5. Install and connect the cold water pipes. Make sure the water pipe is properly sized in accordance with the number of units being operated. Refer to “8. Water Connections” on page 28 for additional information.
  6. Connect and route the condensate drain lines to a suitable discharge location. Refer to “8. Water Connections” on page 28 for additional information.
  7. Do Not connect communication cables at this time.
  8. Power up all the units and assign a unique number, one through ten to each unit. Set the STAGING to ON.

Intellihot iQ251D Series Deionized Wall Hung Water Heater -
assignIntellihot iQ251D Series
Deionized Wall Hung Water Heater - Subscribe 1 WARNING
Before making any adjustments or connections inside  the water heater cabinet, make sure the power isdisconnected. Unplug the water and/or turn the circuit breaker OFF.
If necessary, press the Power button to turn OFF each water heater in the system and disconnect power from all the units in the system.
Remove the front cover and locate the main circuit board.
Set DIP switch 3 on the electronic board on all units.
a. On the first water heater, locate DIP Switch 3 on the circuit board. Position the switch in the ON position.
b. On any water heater unit between the first and last unit, position all DIP switch 3 switches in the OFF position.
c. On the last water heater, locate DIP Switch 3. Position the switch in the ON position.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
locate12. Using the supplied cables, connect one end of a cable  into either of two jack receptacles (arrows) located on the circuit board and the other end to the jack in thenext unit.Intellihot iQ251D Series Deionized Wall Hung Water Heater - Dip
Switcha. Pass the communication cable, supplied with water heater, through the grommet located in the bottom of the cabinet.Intellihot iQ251D Series Deionized Wall Hung
Water Heater - throughb. Secure the cable using a zip tie.
c. Replace the front cover.

Reconnect the power and turn the water heater ON.

The water heaters should now be ready to communicate with each other and operate as a single system. Note: Whenever a change is made to any one water heater, all the other units in the system will be automatically updated to the new settings.
13.2.1 telliCare for Multiple Units
If cascading mulitple units, the Wi-Fi module on all units besides “Unit 1” in the sequence need to be disconnected to make room for cascade communication cables. Remove the attached cable at each end from the referenced jacks and set aside.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
through 1

Maintenance

14.1 Draining the Water Heater

CAUTION
Hot water can cause burns to the skin. The water temperature is factory set to 120°F (49°C). To avoid burns, make sure the water heater is OFF and the power supply is disconnected. The water heater will remain hot for some time. Wait until the unit has completely cooled before draining the water heater or performing any other maintenance.

  1. Press the Power button to turn OFF the water heater. Disconnect the electrical power.

  2. Close the water supply inlet and outlet valves. The valve is closed typically when the handle is perpendicular to the pipe, as shown in the illustration.Intellihot iQ251D Series Deionized Wall Hung Water Heater - supply

  3. Remove the front cover panel. Place a container or other method to retain/divert the water under the heat engine inlet.
    Note: The water heater contains approximately one-half gallon of water. Make sure there is enough capacity to contain or divert the water from inside the water heater cabinet.

  4. Remove the clip holding the pipe into the heat engine.
    Flex the pipe enough to allow the water to drain from the heat engine.Intellihot iQ251D Series Deionized Wall Hung Water Heater -
holding Note: Do not allow the water to pool or stand in the bottom of the water heater cabinet. Remove any spilled water with a clean, dry cloth.

  5. When all the water has drained from the water heater, replace the pipe and the clip.

14.2 Filling the Water Heater

  1. Open the hot water outlet valve. Slowly open the cold water inlet valve.
  2. pen a hot water faucet. Once a steady stream of water flows and all the trapped air is purged from the system, close the hot water faucet.
  3. lug the unit into an electrical power supply.
  4. Open a hot water faucet. The water heater should operate normally.

Wiring Diagrams and Troubleshooting

15.1 Operational Flow Chart

Intellihot iQ251D Series Deionized Wall Hung Water Heater - holding
1 15.2 Complete Wiring Diagram (all models)Intellihot iQ251D Series Deionized Wall Hung Water Heater -
holding 2 15.3 Troubleshooting Guide

Description Possible Cause Remedy

Blower
Speed Fault| • Blower noisy / impeller jammed.
• Disconnected signal wire.
• Wiring faulty.| • Inspect blower / impeller. Clean and remove any obstructions.
• Check PWN signal. Check for loose wires / pins, and repair.
• If the problem persists, turn control panel OFF, shut OFF gas valve, disconnect power from unit, and contact an authorized service technician.
Igniter
Ignition FailureIntellihot iQ251D Series Deionized Wall Hung Water Heater -
Igniter| • Water over-heat switch tripped.
• Faulty DSI, faulty igniter wire, faulty ignition connection, faulty
PCB, bad igniter.
• Low gas pressure.
• Wiring faulty.| • Check the pump, cross-over solenoid, and for electrical noise
(DSI).
• Replace part.
• Adjust gas pressure at regulator, check / increase size of gas
pipe, check for gas pipe blockage.
• If the problem persists, turn control panel OFF, shut OFF gas
valve, disconnect power from unit, and contact an authorized
service technician.
Open Sensors
Inlet / Outlet SensorsIntellihot iQ251D Series Deionized Wall Hung Water
Heater - Sensors| • Unplugged connectors.
• Faulty sensor wiring.
• Faulty sensor.
• Heat engine water outlet
temperature sensor.
• Flue temperature sensor.
• Inlet water temperature sensor.
• Faulty controller.| • Check connectors and ensure they are securely connected.
• Check for nicked or broken sensor wiring or connectors. Also
check for corroded or wet connectors.
• Measure resistance of sensor at connector (18 kΩ at 50°F,
10 kΩ at 77°F, 3 kΩ at 140°F).
• Replace controller.
Faulty Sensors
Inlet / Outlet SensorsIntellihot iQ251D Series Deionized Wall Hung Water
Heater - Faulty Sensors| • Faulty sensor wiring or
faulty sensor.
• Inlet water temperature sensor.
• Heat engine water outlet
temperature sensor.
• Faulty controller.| • Check for nicked or broken sensor wiring or connectors. Also
check for corroded or wet connectors.
• Measure resistance of sensor at connector (18 kΩ at 50°F,
10 kΩ at 77°F, 3 kΩ at 140°F).
• Replace controller.
Heat Engine
Outlet temperature exceeded set limitIntellihot iQ251D Series Deionized Wall
Hung Water Heater - Heat Engine| • Flow rate changes excessive.
• Faulty sensor wiring.
• Faulty sensor.
• Faulty controller.| • Ensure the water flow rate does not change faster than 1 GPM every five seconds.
• Check for nicked or broken sensor wiring or connectors. Also
check for corroded or wet connectors.
• Measure resistance of sensor at connector (18 kΩ at 50°F, 10 kΩ at 77°F, 3 kΩ at 140°F).
• Replace controller.
Flue
Temperature Exceeded Set LimitIntellihot iQ251D Series Deionized Wall Hung
Water Heater - Flue| • Incorrect vent set up.
• High inlet temperature.
• Faulty sensor wiring.
• Faulty sensor.
• Faulty controller.| • If vent pipe material is CPVC or polypropylene, ensure that CPVC is selected in the vent material screen.
• Ensure inlet temperature is lower than 150°F if vent pipe material is PVC or lower than 190°F if vent pipe material is
CPVC or polypropylene.
• Check for nicked or broken sensor wiring and connectors. Also check for corroded or wet connectors.
• Measure resistance of sensor at connector (18 kΩ at 50°F, 10 kΩ at 77°F, 3 kΩ at 140°F).
• Replace controller.
Blocked Flue Fault![Intellihot iQ251D Series Deionized Wall Hung Water Heater

  • Blocked](https://manuals.plus/wp-content/uploads/2023/09/Intellihot-iQ251D- Series-Deionized-Wall-Hung-Water-Heater-Blocked.jpg)| • Exhaust blocked (bird, etc).
    • Backed up condensate.
    • Wiring loose (switch open).| • Check exhaust termination. Check exhaust connection at water heater. Install screens to prevent blockage.
    • Check slope of drain. Check for double loops, air locks, or
    debris in loop.
    • Check wiring.
    Flue sensorIntellihot iQ251D Series Deionized Wall Hung Water Heater - Flue
sensor| • Unplugged connectors.
    • Faulty sensor wiring.
    • Faulty sensor.
    • Flue temperature sensor.
    • Inlet water temperature sensor.
    • Faulty controller.| • Check connectors and ensure they are securely connected.
    • Check for nicked or broken sensor wiring or connectors. Also check for corroded or wet connectors.
    • Measure resistance of sensor at connector (18 kΩ at 50°F, 10 kΩ at 77°F, 3 kΩ at 140°F).
    • Replace controller.
    Cascading
    FaultIntellihot iQ251D Series Deionized Wall Hung Water Heater -
Cascading| • Loss of communication between units.| • Check for broken or nicked communication cable or loose connector.
    • Ensure that the communication cable is not bundled or tied to any high voltage lines.
    • Ensure dip switch (SW3) is ON in first and last units and OFF in all other units.
    • Ensure each unit numbering is unique.
    Water ValveIntellihot iQ251D Series Deionized Wall Hung Water Heater - Water
Valve| • Faulty sensor wiring.
    • Water valve is damaged or inlet strainer is clogged.| • Check for nicked or broken sensor wiring or connectors. Also check for corroded or wet connectors.
    • Replace water valve and/or clean strainer.
    SoftwareIntellihot iQ251D Series Deionized Wall Hung Water Heater -
Software| • Incorrect settings.
    • Incompatible settings.
    • Incorrect software version.
    • Faulty wiring.| • Review and correct settings.
    • Review and correct settings.
    • Update software version.
    • Check for nicked or broken sensor wiring or connectors. Also check for corroded or wet connectors.
    System AlertIntellihot iQ251D Series Deionized Wall Hung Water Heater -
System Alert| • A system alert is present (main menu screen).
    • Malfunction of monitored part or system.| • Refer to the remedy for indicated part or system.
    FaultIntellihot iQ251D Series Deionized Wall Hung Water Heater - Fault
1| • A fault or error is present (main menu screen).
    • Malfunction of monitored part or system.| • Refer to the remedy for indicated part or system.
    Alert / Error / FaultIntellihot iQ251D Series Deionized Wall Hung Water
Heater - Error 1| • An alert, fault, or error is present  (active screen).
    • Malfunction of monitored part or system.| • Refer to the remedy for indicated part or system.
    AliveIntellihot iQ251D Series Deionized Wall Hung Water Heater -
Alive| • Shows status of water heater.
    • Sleep mode.
    • Sleep mode passcode protected.
    • Indicates a service problem exists within the monitored parts.
    • Indicates an alert exists within the monitored systems.
    • Indicates a fault exists within the monitored parts or system.| • Touch display screen to awake.
    • Touch display screen to awake and enter passcode.
    • Refer to the remedy for indicated part or system.
    • Refer to the remedy for indicated part or system.
    • Refer to the remedy for indicated part or system.

Serviceable Parts

16.1 Electrical Components

Intellihot iQ251D Series Deionized Wall Hung Water Heater - Alive
1

Item Part Number Description
1 IGT-SPR0005 Igniter Module (DSO
2 IGT-SPR0002 Control Board
3 IGT-SPRO089 Small Screen Display Kit
4 IGT-SPRO065 Transformer

16.2 water Line

Intellihot iQ251D Series Deionized Wall Hung Water Heater - Alive
4

Item Part Number Description
5 IGT-SPRO021 Flow Sensor Kit
6 IGT-CST0029 Side Cast
7 IGT-SPRO012 Water Outlet Fitting

16.3 Blower, Gas ValveIntellihot iQ251D Series Deionized Wall Hung
Water Heater - Alive 2

Item Part Number Description
10 IGT-SPR0008 Blower Kit
11 IGT-ELC0012 Blower Adapter Plate
12 IGT-ELC0147 Gray Swirl Plate
13 IGT-ELC0020 Gas Valve Harness
14 IGT-SPR0011 Gas Valve Kit
15 IGT-SPRO097 High Temp Sesnor
16 IGT-SPRO110 Sensors Kit
17 IGT-SPR0066 Resettable Switch
18 IGT-SPRO106 Electrode Kit

16.4 Exhaust &AIR INTAKE 

Intellihot iQ251D Series Deionized Wall Hung Water Heater - Alive
3

Item Part Number Description
19 IGT-SPR0005 Igniter Module (DSO
20 IGT-SPR0002 Control Board
21 IGT-SPRO089 Small Screen Display Kit

16.5 Miscellaneous

Part Number Description
IGT-ELC0092 25 ft cascading cable
IGT-ELCO232 50 ft cascading cable
IGT-SPRO109 0-Ring kit
IGT-SPRO110 Sensors Kit
IGT-SPRO085 iOT Kit
IGT-ELC0181 DSI to Electrode HV Cable
IGT-ELCO289 Display Harness
IGT-ELC0015 Wiring Harness
IGT-SPRO111 Burner Kit
IGT-ELC0087 iQ251D Flow Sensor Wiring Harness
IGT-SPRO067 BMS Kit
IGT-VL0039 Stainless Steel T&P Valve

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