1. Universal Electronic Aquastat® L7224U1002 Training Module
Includes Honeywell’s AquaReset® Outdoor Reset Solution

2. What you will learn L7224U Product Overview Key Features Installation
Set Up
Troubleshooting
Product Cross Reference
L7224U Advantages

3. L7224U Universal Electronic Aquastat®
What is the L7224U1002?
Universal electronic Aquastat that provides circulator, burner and boiler temperature control with electronic temperature sensing in an oil fired hydronic heating appliance.
Provides status and diagnostic information through an LED display to enhance the diagnostic process.
One part number:
L7224U1002

4. Aquastat® Key Features
Electronic Aquastat®
L7224U1002
Triple Aquastat (High, Low, Circulator Control)
Outdoor reset ready
EnviraCOM™ communications enabled
Electronic configuration
Diagnostic updates through LED Display
Provides multizone control
Horizontal or vertical flange mounting

5. L7224U Universal Electronic Aquastat
Why choose the Honeywell L7224U1002?
Universal Compatibility
Replaces over 40 existing Honeywell controls
Easy Installation
Redesigned to simplify wiring
Direct or remote mount
Superior Performance and Accuracy
+/- 2 degree accuracy
Multi-Function LED Display
Speeds installation and troubleshooting
Push button product set up & configuration
Get set point, temperature and diagnostic info
EnviraCOMTM communications enabled
Easily add outdoor reset with 3 wires
Remote diagnostics
OnWatch Diagnotic compatible

6. Additional L7224U features
Remote 48” sensors available
One Amp slow-blow fuse
Improved terminal layout and multiple knockouts
Vertical, Horizontal, and Flush-Mounting - configurable for single-function use
Low Limit can be disabled (cold start boiler applications)
Outdoor reset functionality enabled when combined with W8735S1000 AquaReset® kit

7. L7224U Features Enviracom™ Terminals Flush Mounting Tabs (2) Push
Buttons – Configuration
& Access Diagnostic
Information
Thermostat
Terminals
EnviraCOM Data port
Digital Display
Line Voltage
Terminals
Keyed Sensor
Connector
Capacitor
Multiple Sensor Holes
Transformer
Fuse
Relays

8. Ranges and Ratings Setting Ranges +/-2 Degree Accuracy
High Limit: – 240°F
High Limit Differential
(new feature): – 20°F
Low Limit: – 220°F
Low Limit Differential: – 25°F
Electrical Ratings
Voltage: VAC 60 HZ
Burner: Amps
Circulator: Amps
Zone Controller (ZC): 7.4 Amps
Environmental Ratings
Temperature: °F to 150 °F
Humidity: 0 to 95% relative humidity

9. Installation

10. Keyed sensor connector plugs into circuit board
Wiring of the L7224U
Well mounting
PN in.
Included in the box
Flush mounting
PN in.
Keyed sensor connector
plugs into circuit board

11. Wiring of the L7224U -- Thermostat
Terminals 3 2 1 T
Enviracom™
Connect AquaReset® and other
Enviracom devices

12. Wiring of the L7224U – Line Voltage
Terminals
ZR Power from zone relay
to burner
L1 Power hot
L2 Power neutral
C2 Circulator common
B2 Burner common
C1 Circulator hot
B1 Burner hot
ZC Power to zone
circulator relay

13. Connecting AquaReset®
Thermostat
Terminals 3 2 1 T
Enviracom™
Wire 1,2,3 terminals on Aquastat to 1,2,3 terminals
to the Outdoor Reset Module

14. Connecting AquaReset®
Enviracom™
Terminals
Wire 1,2,3 terminals on Aquastat to 1,2,3 terminals
to the Outdoor Reset Module. Mount outdoor sensor
Outside and connect wires to the OT terminals
Outdoor Sensor
Terminals 1 2 3 OT OT

15. Set Up

16. I Set Up of the L7224U To adjust the settings
Press the UP, DOWN, and I buttons simultaneously for three seconds
Press the I button until the desired feature is displayed
Then press UP and/or DOWN to move the set points to desired values
After 60 seconds without any buttons pressed, the control automatically goes back to READ mode
Display
In RUN mode the Aquastat will flash boiler temp (bt) followed by the temperature
To read settings press the I key to scroll thought the functions I
Increase value
of setting
Decrease value
Cycles through
Settings & conditions

17. I Set Point Adjustments Increase value of setting Decrease value
Cycles through
Settings & conditions

18. L7224U Electronic Aquastats® (LED LIGHTS)
EnviraCOM
Network Active
Thermostat
Calling
Burner
Energized
Power to
Zone Circulator
Interrupted
Circulator
Powered

19. Digital Readout of System Conditions
Run mode – display shows boiler temperature
Display
Text Description Shows
bt Boiler Temperature
HL High Limit
LL Low Limit
Hdf High Limit Differential
Ldf Low Limit Differential
tt Local Thermostat Status
tte Enviracom Thermostat Status
brn Burner Status
cir Circulator Status
Zc Zone Control
Zr Zone Request
err Error Code
°f Degrees Fahrenheit
°c Degrees Celsius
LED display
Push “I” button
to see other values

20. Digital Readout of System Outdoor Reset Functions
The following messages are only available when connected to a W8735S1000 outdoor reset kit and/or W8735S1008 domestic hot water priority kit
Display
Text Description Shows
duu ZR configured as Domestic
Hot Water Request
ASC Anti Short-Cycle timeout
bSP Boiler Setpoint
dhc DHW module connected
ot Outdoor temperature
otL Outdoor temperature low
otH Outdoor temperature high
btL Boiler temperature low
bP Boost Period
bS Boost step
UUS Warm weather shutdown
temperature
LED display
Push “I” button
to see other values

21. L7224U Electronic Aquastats® (Digital Readout of System Conditions)
Run mode – display shows boiler temperature
LED display
Technicians Quick Reference Guide #
Push “I” button
to see other values

22. Troubleshooting

23. Troubleshooting: L7224U Electronic Aquastats® (Error Codes)
Is there an error code on the display?
Error
Code Cause/Action
Err 1 Sensor fault; check sensor
Err 2 ECOM fault; check EnviraCOM™ wiring
Err 3 Hardware fault; replace control
Err 4 B1 fault; check B1 wiring/voltage
Err 5 Low line voltage; check L1-L2 110 Vac
Err 6 Fuse; check ECOM wires, replace fuse
Err 7 EEPROM, HL, LL, Hdf, Ldf; Reset to default values. Restore desired settings.
Err 8 Repeated B1 fault (voltage present at B1 when output is
turned off); check B1 wiring/voltage

24. Troubleshooting: L7224U Electronic Aquastats® (AquaReset Error codes)
Is there an error code on the display?
Error
Code Cause/Action
Err 9 Outdoor reset system failure, check wiring
Err 10 Boost Failure, check outdoor reset curve settings
Err 11 Domestic Hot Water module failure, check wiring
Error codes 9, 10 and 11 only apply when AquaReset and/or Domestic Hot Water priority modules connected to Aquastat

25. Troubleshooting: L7224U Electronic Aquastats®
On Watch QuickLookTM 72
For Honeywell EnviraCOM™ enabled equipment
Read EnviraCOM™ Error Codes
Line Voltage
Aquastat Well Temperature
The QuickLookTM 72 is available through

26. Product Cross Reference

27. Product Cross Reference
Where do I find Honeywell universal electronic aquastat cross reference information?
Honeywell Application Selection and Cross
Reference Guide – Form
Honeywell Laminated Truck Visor – Form O
Honeywell Residential Technical Support: O

28. Aquastat® Cross Reference Table
This chart can be found in the Residential Combustion Application Guide: Form #

29.
See Cross Reference Search box in right column.

30. L7224U Advantages
When promoting the Honeywell L7224U1002 keep these advantages in mind:
This Universal control replaces over 40 existing Honeywell controls.
Save time searching for the exact replacement parts
Stock less parts on the shelf and in the truck
Installation is easy with this redesigned control.
Wiring has been simplified
Mounting choices - control can be direct or remote mount
Performance and accuracy are superior to past controls.
+/- 2 degree accuracy
The multi-function LED display means less time spent on installation and troubleshooting.
Push button product set up & configuration
EnviraCOMTM communications enabled is an added advantage providing remote diagnostic capabilities.

31. L7224U Universal Electronic Aquastat Knowledge Test
Now that you completed this training module, take the short quiz to test your knowledge.

32. Test
The L7224U provides temperature control of circulators, burners and boilers with electronic temperature sensing? T of F
The L7224U is considered a single function aquastat which provides high limit and low limit control? T or F
The L7224U is accurate within +/- 2 degrees? T or F
A 48” sensor is available to accommodate application requirements? T or F
Setpoints are easily adjusted with the up and down push buttons? T or F

33. Test
The “I” button cycles through settings and conditions? T or F
Error codes can be read only through the LED display? T or F
The low limit can be disabled for a cold start boiler application? T or F
Honeywell provides cross reference information for replacing over 40 existing controls? T or F
The L7224U has a LED light that shows whether the burner is energized? T or F

34. Answer Key T F