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AQUASTAT at InspectApedia.com
L7224A,C; L7248A,C,L Oil and
Electric Boiler
Electronic Aquastat
APPLICATION
The L7224A,C and L7248A,C,L 2012 Compliant
Electronic Aquastat
temperature sensing in a UL limit-rated control with a
single sensing probe. The L7224A,C and L7248A,C,L
control the circulator, oil or electric burner or
contactor, and boiler temperature. The L7224/L7248
is "Outdoor Temperature Reset" ready which is
enabled when connected to the W8735Y1000
wireless or W8735S1000 wired Outdoor Reset Kit.
Outdoor Reset with the L7224/L7248 is intended for
all applications except for tankless coil systems for
domestic hot water. Compliance to 2012 DOE
regulation ensures efficiency is maximized without
interfering with domestic hot water demand.
The L7224A,C and L7248A,C,L replace the L8124A,
L8124C, L7124A,C, L7148A and L8148A Controllers.
The L7224A,C and L7248A,C,L series controls
provide status and diagnostic information through an
LED display combined with LED lights as well as
EnviraCOM™ communications enabled thermostats
and diagnostic tools to enhance the diagnostic
process.
L7224/L7248 Aquastat Controllers are intended for
use in residential-type applications.
Operation of this control may delay the burner operation while the residual heat is
circulated out of the boiler.
NOTE: This operation may be different than earlier electronic Aquastat
revisions which did not implement thermal purge.
®
Controllers provide electronic
2012 DOE Compliance and Operation
®
Controllers
INSTALLATION INSTRUCTIONS
IMPORTANT
Use of Outdoor Temperature Reset on a tank-
less coil application requiring a Low Limit set-
ting will result in reduced system
effectiveness and efficiency.
SPECIFICATIONS
Electrical Ratings:
Voltage: 120 Vac, 60 Hz.
Power: 7 VA maximum at 120 Vac plus external loads.
Thermostat current: 100 mA nominal at 24 Vac.
Burner Relay:
7.4 A at 120 Vac Full Load Amperage (FLA);
44.4 A inrush Locked Rotor Amperage (LRA);
Less Ignition Load: 360 VA.
Circulator Relay:
7.4 A at 120 Vac FLA; 44.4 A inrush LRA.
Zone Controller (ZC): 7.4 A at 120 Vac FLA;
44.4 A inrush LRA.
NOTE: All loads combined cannot exceed 2000 VA.
Environmental Ratings:
Temperature: -30 °F to +150 °F (-34 °C to +66 °C).
Humidity: 0 to 95% relative humidity, noncondens-
ing.
Approvals:
Underwriters Laboratories Inc. Component Recog-
nized.
Canadian Underwriters Laboratories Inc. Component
Recognized.
®
68-0281-18
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Table of Contents
Related Manuals for Honeywell Aquasat L7224 A Aquasat L7224 C
Summary of Contents for Honeywell Aquasat L7224 A Aquasat L7224 C
- Page 1 CLICK ANYWHERE on THIS PAGE to RETURN to HONEYWELL L7224U UNIVERSAL AQUASTAT at InspectApedia.com L7224A,C; L7248A,C,L Oil and Electric Boiler ® Electronic Aquastat Controllers INSTALLATION INSTRUCTIONS IMPORTANT APPLICATION Use of Outdoor Temperature Reset on a tank- less coil application requiring a Low Limit set-...
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Page 2: Installation
L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER INSTALLATION Accessories: W8735Y1000 Wireless Outdoor Reset Kit W8735ER1000 Wireless Outdoor Reset Module C7089R1013 Wireless Outdoor Temperature Sensor When Installing this Product... (requires W8735ER1000) 1. Read these instructions carefully. Failure to W8735S1000 AquaReset™ Outdoor Reset Kit follow them could damage the product or cause (includes 50022037-002 Outdoor Reset Module a hazardous condition. -
Page 3: New Installation
L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER IMPORTANT Immersion well must fit sensing element and SENSOR WIRES sensor must rest against bottom of well. CONTROLLER CASE BOILER New Installation IMMERSION SENSOR Order well assemblies separately; see Table 1 and form WELL no. -
Page 4: Replacement Sensor Installation
L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER WIRING SENSOR WIRES BOILER WARNING Electrical Shock Hazard. IMMERSION SENSOR Can cause serious injury or death. WELL Disconnect power supply before making wiring connections to prevent electrical shock or equipment damage. HEAT-CONDUCTIVE COMPOUND All wiring must comply with local electrical codes and (OPTIONAL) ordinances. -
Page 5: Adjusting Settings
L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER A separate electromechanical high-limit is not required in a system that uses this control to meet Table 3. Adjustable Features. Underwriters Laboratories Inc. requirements for oil- fired boiler assemblies, UL 726. Display Definition High Limit. On the L7224 models, the High Limit, Low Limit, Low Limit Differential, and Anti Short-Cycle time can be High Limit Differential. -
Page 6: High Limit Controller
L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER Operation Table 4. Display readout definitions. The L7224 and L7248 models can be in any of four operational states: Normal, High Limit, Low Limit and Text Description Display Error. The controller moves back and forth from Error Code (if one is present) High Limit to Normal to Low Limit state as part of normal operation. - Page 7 Water demand occurs. Domestic Hot Water not interfere with domestic hot water call for heat or demands are serviced immediately, without boilers equipped with Honeywell outdoor reset any delay. accessories. For warm start models where a Low Limit must be set, thermal purge is not applied.
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Page 8: Troubleshooting
L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER Thermal Purge and Domestic Hot CHECKOUT Water Put the system into operation and observe at least one The thermal purge feature is automatically disabled complete cycle to make sure that the controller whenever there is a call for domestic hot water either operates properly. - Page 9 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER Table 6. L7224/L7248 Controller Operating Sequence. Action System Response Thermostat calls for heat. Circulator starts when water temperature is above Low Limit setting (if applicable) or above the Thermal Purge Temperature Limit (tPL) if Thermal Purge is enabled. Boiler temperature is checked.
- Page 10 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER Table 7. L7224/L7248 Controller Operating Sequence with multiple zones connected through the ZR ter- minal. Action System Response Zone Request (ZR) terminal is connected to Boiler temperature is checked. Burner starts when water L1 (Zone calls for heat). temperature is below High Limit setting or at or below the Thermal Purge Temperature Limit (tPL) for cold start boilers if the Thermal Purge Temperature Limit is enabled.
- Page 11 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER Table 10. LED Error Codes. Aquastat EnviraCO Error Code Cause/Action M Alarm Err1 Aquastat sensor fault; check water sensor. Err2 ECOM fault; check EnviraCOM™ wiring. Err3 Excessive electrical noise or frequency out of range. Hardware fault; replace controller. 18, 58 Err4 B1 fault;...
- Page 12 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER Table 11. Troubleshooting Guide System Diagnostic Condition Condition Check Action Boiler is hot, Display is ON. 120 Vac at C1-C2 • 120 Vac at C1-C2, check wiring to pump. house is cold. • Wiring OK, is pump running? •...
- Page 13 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER LINE VOLTAGE W8735Y1000 OR INDIRECT W8735S1000 TANK AQUASTAT 1 2 3 OT OT C7089U1006 TH9421C OUTDOOR INDIRECT SENSOR TANK CIRCULATOR R7184/R7284 (HOT) L2 LIMIT L7224 BURNER ENVIRACOM™ BURNER MOTOR TERMINAL MOTOR SENSOR IGNITER IGNITER LINE VOLTAGE VALVE...
- Page 14 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER ELL=OFF TO ADDITIONAL R845A ZONE 2 RELAYS FOR OTHER ZONES CIRCULATOR (HOT) L2 R845A RELAY ZONE 2 ZONE 2 LOW VOLTAGE ENVIRACOM THERMOSTAT LOW VOLTAGE TERMINALS THERMOSTAT W8735Y1000 OR W8735S1000 L7248L 1 2 3 OT OT C7089U1006 OUTDOOR SENSOR...
- Page 15 L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER W8735Y1000 OR W8735S1008 W8735S1000 MULTI-ZONE 1 2 3 TS TS 1 2 3 OT OT RELAY PANEL C7089U OUTDOOR SENSOR 32003971-003 TEMPERATURE SENSOR R7184/R7284 (HOT) L2 LIMIT L7224 BURNER ENVIRACOM™ BURNER MOTOR MOTOR TERMINAL SENSOR IGNITER IGNITER...
- Page 16 Home and Building Technologies In the U.S.: Honeywell 715 Peachtree Street NE ® U.S. Registered Trademark Atlanta, GA 30308 © 2018 Honeywell International Inc. 68-0281—18 M.S. Rev. 03-18 customer.honeywell.com Printed in United States...