Honeywell L7224 Installation Manual

69-1720EFS-03

L7224U Oil Electronic Aquastat

Controller

INSTALLATION INSTRUCTIONS

APPLICATION

The EnviraCOM™ enabled L7224U Oil Electronic

Aquastat sensing in a UL limit-rated controller with a single sensing probe. The L7224U controls the circulator, oil burner and boiler temperature.

The L7224U is “Outdoor Temperature Reset” ready, which is enabled when connected to the Outdoor Reset Module. This option is intended for all applications except for tankless coil systems for domestic hot water.

The L7224U replaces the L8124A, L8124C, L7124U, L7148A, L7248A,C, L7224A,C, and L8148A controllers and is intended for residential applications.

IMPORTANT:

Controller provides electronic temperature

Use of Outdoor Temperature Reset on a tankless coil application requiring a Low Limit setting may result in limited system effectiveness and reduced efficiency.

The L7224U provides 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.

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, noncondensing.

Approvals:

Underwriters Laboratories Inc. Component Recognized. Canadian Underwriters Laboratories Inc. Component

Recognized.

Accessories (Ordered Separately):

W8735S1000 AquaReset™ Outdoor Reset Kit (includes

50022037-002 Outdoor Reset Module and C7089U1006 Outdoor Temperature Sensor)

W8735S1008 AquaReset™ Domestic Hot Water Kit

(includes 50022037-005 Domestic Hot Water Module and 32003971-003 Sensor)

C7089U1006 Outdoor Temperature Sensor (used with

the 50022037-002)

32003971-003 Temperature Sensor (used with

50022037-005) Sensor (See Table 2). Sensor Well Clamp 121371AA. 14,000,485-016 1/4 in. (6.35 mm) diameter, 1-1/4 in.

(31.75 mm) length glass cartridge Fuse, 1 A,

Slow-Blow. 120650 Heat Conductive Compound.

Table 1. Wells for L7224U Controller.

Part

Number

123869A 1/2 (12.7) NPT 3 (76.2) 1-1/2 (38.1) 123870A 3/4 (19.05) NPT 3 (76.2) 1-1/2 (38.1)

Part Number

50001464-001 12 (304.8) Well-mounted controls 50001464-002 18 (457.2) Flush-mounted controls 50001464-003 24 (609.6) 50001464-004 36 (914.4) 50001464-005 48 (1219.2)

Spud Size

in. (mm)

Table 2. Sensors for L7224U Controller.

Insertion

in. (mm)

Length in.

(mm) Application

Insulation

in. (mm)

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

WARNING

INSTALLATION

When Installing this Product...

1. Read these instructions carefully. Failure to follow

them could damage the product or cause a hazardous condition.

2. Check the ratings given in the instructions and on

the product to make sure the product is suitable for your application.

3. The installer must be a trained, experienced service

technician.

4. After installation is complete, check out product

operation as provided in these instructions.

5. Set High Limit, Low Limit and Differential to the set-

tings recommended by the boiler OEM.

6. Record the maximum High Limit setting from the

replaced controller in the text box provided on the cover insert label.

7. Record the High Limit setting at the time of installa-

tion in the text box provided on the cover insert label.

3/4

(75)

7-1/8 (181)

Electrical Shock Hazard. Can cause severe injury, death or property damage.

Disconnect power supply before beginning installation to prevent electrical shock or equipment damage.

Mounting

The L7224U can be mounted in a well mount, horizontal or vertical position, or flush mounted remote from the well.

IMPORTANT

Immersion well must fit sensing element and sensor must rest against bottom of well.

New Installation

Order well assemblies separately; refer to Table 1 and form no. 68-0040, Immersion Wells and Compression Fittings for Temperature Controllers. Boilers usually have tappings that allow the well to be mounted horizontally so boiler water of average temperature can circulate freely over the well. See Fig. 1 for mounting dimensions.

6-1/2 (166)

5-11/16

(145)

3/8

(10)

2-5/8 (67)

4-1/4 (109)

3-13/32 (86)

2x 1/4 (7) x 3/8 (9)

Fig. 1. L7224U mounting dimensions in inches (mm).

1. Turn off all power and drain the boiler, if applicable.

2. If no tapping is provided, prepare properly sized and

threaded tapping near the top of the boiler.

3. Sparingly coat the well threads with pipe dope.

NOTE: Do not attempt to tighten by using the case as a

handle.

69-1720EFS—03 2

3-1/32

(77)

1-3/16

(30)

1-1/8 (29)

1/16 (2)

4. Install the well in the boiler tapping and tighten

securely.

5. Refill boiler and check for water leakage.

6. Identify if installation requires vertical or horizontal

mounting.

7. Remove the well knockout, for either vertical or

horizontal mounting, by carefully prying the knockout from the back of the case, using a flat-bladed screw driver. Refer to Fig. 2.

2-1/16 (53)

M22147B

Fig. 2. Removing horizontal or vertical mounting

SCREWDRIVER

M22118

KNOCKOUT FOR HORIZONTAL MOUNT

KNOCKOUT FOR VERTICAL MOUNT

SENSOR WIRES

IMMERSION WELL CLAMP SCREW

IMMERSION WELL CLAMP

M16120

HEAT-CONDUCTIVE COMPOUND (OPTIONAL)

CONTROLLER CASE

BOILER

IMMERSION WELL

SENSOR

LINE

THERMOSTAT

TERMINALS

ENVIRACOM

TERMINALS

DISPLAY

SENSOR CONNECTOR

SENSOR HOLES

FUSE

FLUSH MOUNTING TAB (2)

M32197

LED's

ZC C1

8. Loosen but do not remove the well clamp screw.

9. Fit the case into the well so the clamp on the case

slides over the flange on the well.

10. Securely tighten the clamp screw.

11. Insert the sensor element into the well until it

bottoms. (If necessary, slightly bend the wire inside the case to hold the sensor against the bottom of the well.)

12. Turn power ON.

13. Set High Limit, Low Limit and Differentials to the

settings recommended by the boiler OEM. (See OPERATION section, also refer to INSTALLATION steps 6 and 7.)

IMPORTANT

Best thermal response is obtained with a well that snugly fits the sensor. Insert the sensor until it rests against the bottom of the well. Use a well of correct length and bend the wiring, if necessary, to hold the bulb against the bottom of the well.

If the well is not a snug fit on the sensor, use the heat-conductive compound (furnished with TRADELINE® models) as follows: Fold the plastic bag of compound lengthwise and twist it gently. Then snip off end of bag and work the open end of the bag all the way into the well. Slowly pull out the bag while squeezing it firmly to distribute compound evenly in the well. Bend the wiring, if necessary, to hold the sensor against the bottom of the well and to hold outer end of the sensor in firm contact with the side of the well. See Fig. 3. Wipe excess compound from the outer end of the well.

knockout.

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

Fig. 3. Position of sensor in immersion well.

Flush-Mounted Aquastat Replacement

Turn off all power and remove the old controller. Refer to the cover insert of the old controller to identify and tag each external lead as it is disconnected. If the old well is unsuitable for the new installation, remove it and replace it with a suitable new well. If the old well is suitable, use it. See Fig. 1 and 4 for mounting tab location.

Fig. 4. Location of L7224U flush-mounting tabs and

3 69-1720EFS—03

LEDs.

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

WARNING

SENSOR WIRES

M22026

HEAT-CONDUCTIVE COMPOUND (OPTIONAL)

BOILER

IMMERSION WELL

SENSOR

LINE

1 2 3 OT OT

C7089U1006 OUTDOOR SENSOR

50022037-002 OUTDOOR RESET MODULE

1 2 3 TS TS

50022037-005 DOMESTIC HOT WATER MODULE

32003971-003 TEMPERATURE SENSOR

M29651

Well-Mounted Aquastat Replacement

Turn off all power and remove the old controller. Refer to the cover insert of the old controller to identify and tag each external lead as it is disconnected. If the old well is unsuitable for the new installation, remove it and proceed with instructions for new installation. If the old well is suitable, use it.

1. Loosen, but do not remove, the well clamp screw on

the side of the controller case.

2. Position immersion well clamp snugly over the

flange of the adapter and tighten the clamp screw.

3. Insert the sensor into the well as shown in Fig. 5.

(If desired, distribute the heat-conductive compound in the tube prior to sensor insertion, as described in New Installation.)

4. Make sure sensor is fully seated to bottom of well

(Fig. 5). Use a small pencil to measure depth of sensor in well, if necessary.

Fig. 5. Replacement sensor installation.

Replacement Sensor Installation

Turn off all power and carefully disconnect sensor from circuit board by pulling gently on the connector.

1. Gently pull sensor from thermo well and through cir-

cuit board by pulling on leadwires.

2. Carefully align replacement sensor with hole in

circuit board and guide through Aquastat case and into well. Refer to Fig. 5.

3. Make sure sensor is fully seated to bottom of well

(see Fig. 5). Use a small pencil to measure depth of sensor in well, if necessary.

4. Connect sensor to circuit board by pressing

connector on sensor unit into mating connector on circuit board (refer to Fig. 6).

5. For remote sensors (flush mounted Aquastat) be

sure to use the 121371AA clamp to securely hold sensor in place. See Accessories.

WIRING

Electrical Shock Hazard. Can cause serious injury or death.

Disconnect power supply before making wiring connections to prevent electrical shock or equipment damage.

All wiring must comply with local electrical codes and ordinances. Do not exceed the specifications in the Application section when wiring this controller.

69-1720EFS—03 4

IMPORTANT

The terminals on these Aquastat Controllers are approved for use with copper wire only.

Follow the appropriate wiring diagrams shown on the inside of the front cover of the L7224U or in Fig. 9–13.

Refer to Fig. 6 for Connections for the optional Outdoor Reset Module and the Domestic Hot Water (DHW) module. In subsequent wiring diagrams these modules will be displayed with a dotted line signifying that they are optional.

Fig. 6. Wiring the Outdoor Reset Module and the

Domestic Hot Water Module.

OPERATION

General

The L7224U Oil Electronic Aquastat Controller is a primary safety limit-rated device designed for use with oil fired boilers with line voltage burners and circulators. Many boilers do not include wiring or controller compartments as part of the design, but are provided with an integral, replaceable, immersion well that is the mounting hardware for the Aquastat Controllers. Wiring to the other controllers is done through flexible metal conduit.

For boilers that do include a remotely (flush) mounted controller, the wiring may be completed with conduit or routed behind the boiler sheet metal.

A separate electromechanical High Limit is not required in a system that uses this controller to meet Underwriters Laboratories Inc. requirements for oil-fired boiler assemblies, UL 726.

On the L7224U, the High Limit, High Limit Differential, Low Limit, and Low Limit Differential and Anti-Short Cycle time can be adjusted to the setting recommended by the boiler OEM.

The overall range of the High Limit is from 130° F to 240° F (54° C to 116° C). Select devices may have different ranges. Some models have limited ranges on the High Limit setpoint; this limited range is listed on the device label.

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

The range of the Low Limit is from 110° F to 220° F (43° C to 104° C). Select devices may have different ranges. The range of the Anti-Short Cycle time is from OFF to five minutes.

If a 50022037-002 “Outdoor Reset Module” is installed, the reset curve can be set by entering the minimum outdoor temperature, minimum (water or boiler) temperature, and maximum outdoor temperature on the 3-digit display. The range of the minimum outdoor temperature is from -40°F to 40°F (-40°C to 4.4°C) and has a default setting of 0°F (-18°C). The range of the maximum outdoor temperature is from 30°F to 70°F (-1°C to 21°C) and has a default setting of 40°F (4.4°C). The range of the minimum (water or boiler) temperature is from 80°F to 180°F (27°C to 82°C) and has a default setting of 130°F (54°C). See the “Outdoor Reset Module” Installation Instructions (form number 69-2335) for more information on setting the boiler reset curve and all related parameters.

The L7224U is designed for use with 24 Vac electronic and electromechanical thermostats or EnviraCOM™ enabled thermostats, and have screw-type terminals for easy field connection.

To replace a L8148A,C L7148A or L7248A,C controller, the Low Limit function must be disabled; see Adjusting Settings for directions.

Adjusting Settings

To discourage unauthorized changing of Aquastat settings, a procedure to enter the ADJUSTMENT mode is required. To enter the ADJUSTMENT mode, press the

UP, DOWN, and I buttons (refer to Fig. 9) simultaneously for three seconds. Press the I button until the feature requiring adjustment is displayed:

Display Definition

HL_ High Limit. Hdf High Limit Differential. LL_ Low Limit. Ldf Low Limit Differential. duu ZR input configured as external Domestic Hot

Water (DHW) request (ON/OFF)

ASC Anti Short-Cycle Timeout (seconds); “OFF” is

disabled.

otL Outdoor Temperature Low (minimum)

parameter for the outdoor reset curve (F or C)*

otH Outdoor Temperature High (maximum)

parameter for outdoor reset curve (F or C)*

btL Boiler Temperature Low (minimum) parameter

for outdoor reset curve*

bP Boost Period (minutes). “OFF” is displayed if

Boost is inactive*

bS Boost step (F or C) shown only if Boost is active

(bP=ON)*

UUS Warm Weather Shutdown Temperature (F or

C)*

F-C Temperature units (F or C)

* Settings available for adjustment on the 3-digit display

only if the AquaReset Outdoor Reset Module is installed.

Then press the UP and/or DOWN buttons to move the set point to the desired value. After 60 seconds without any button inputs, the controller will automatically return to the RUN mode.

To use the L7224U in a cold start boiler application, disable the Low Limit function by pressing the UP arrow button, DOWN arrow button and I button simultaneously for three seconds. Then push the I button until LL_ is displayed. Then press the down arrow button until OFF is displayed.

Display

In the RUN mode, the Aquastat will flash “bt” (boiler temp) followed by the temperature (i.e., 220), followed by °F or °C.

To read boiler settings, press the I key to read the parameter of interest. For example, press I and HL (High Limit) is displayed, followed by a three-digit number, i.e., 220, followed by °F or °C. Pressing the I button again will display the LL (Low Limit) followed by a three-digit number and the corresponding degree designator. See Fig. 7 for explanation of display readout.

After approximately 60 seconds without any key presses, the display will enter a dim display mode. To return to the bright display mode, simply press and release any key.

5 69-1720EFS—03

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

LOW LIMIT SETTING

HIGH LIMIT SETTING

SWITCH BREAKS ON TEMPERATURE RISE. BURNER TURNS OFF. CIRCULATOR OPERATES ON A CALL FOR HEAT.

SWITCH MAKES ON TEMPERATURE FALL. BURNER OPERATES ON A CALL FOR HEAT.

WITH NO HEATING DEMAND, SWITCH BREAKS ON TEMPERATURE RISE.

SWITCH MAKES ON TEMPERATURE FALL, BURNER IS ON TO MAINTAIN MINIMUM WATER TEMPERATURE. CIRCULATOR IS OFF.

M23365

WHEN WATER REACHES LOW LIMIT SETTING, THE BURNER SHUTS OFF OR THE CIRCULATOR PUMP STARTS (WHEN CALLING FOR HEAT).

10ºF (6ºC) DIFFERENCE

Text

Err

HdF

Ldf

ttE

brn

Cir

ELL duu

ASC

bSP

dhc

otL

otH

btL

UUS

°F

°C

OFF

DISPLAY SHOWS LOCAL SETTING; NOT THE SETTING AS MODIFIED BY AN EXTERNAL ENVIRACOM CONTROL.

SETTINGS ARE VIEWABLE ONLY IF THE OUTDOOR RESET MODULE AND OUTDOOR TEMPERATURE SENSOR ARE INSTALLED AND FUNCTIONING PROPERLY.

SETTINGS ARE VIEWABLE ONLY IF THE DOMESTIC HOT WATER MODULE AND SENSOR ARE INSTALLED AND FUNCTIONING PROPERLY.

Fig. 7. Explanation of display readout.

*Settings viewable on the 3-digit display only if the “Outdoor Reset Module” is installed.

69-1720EFS—03 6

Description

Error Code (if one is present)

Boiler Temperature

High Limit

High Limit Differential

Low Limit (L7224 only)

Low Limit Differential (L7224 only)

Local Thermostat Status

EnviraCOM Thermostat Status

B1 (Burner) output (ON or OFF)

C1 (Circulator) output (ON or OFF)

ZC (Zone Control) output (ON or OFF)

ZR (Zone Request) Call for HEAT (ON or OFF)

External Low Limit Enabled (L7248L only) ZR Configured as Domestic Hot Water

Request (L7224, L7248L only)

Anti Short-Cycle Timeout

Boiler Setpoint

DHW Module Connected (YES or NO)

Outdoor Temperature

Outdoor Temperature Low

Outdoor Temperature High

Boiler Temperature Low

Boost Period

Boost Step

Warm Weather Shutdown Temperature

Units are displayed in degrees Fahrenheit

Units are displayed in degrees Celsius

Input or Output is OFF

Input or Output is ON

Display

Shows

M29552

Operation

The L7224U can be in any of four operational states: Normal, High Limit, Low Limit and Error. The controller moves back and forth from High Limit to Normal to Low Limit state as part of normal operation. The operating states are:

1. Normal: Boiler temperature went below the High

Limit setting (minus the Differential) and has not exceeded the High Limit setting; or, the boiler temperature went above the Low Limit setting and has not gone below the Low Limit setting (minus the Differential).

2. High Limit: Boiler temperature went above the High

Limit setting and has not dropped below the High Limit setting (minus the Differential).

3. Low Limit: Boiler temperature went below the Low

Limit setting (minus the Low Limit Differential) and has not gone above the Low Limit setting.

4. Error: The controller has detected an error condition

(e.g., open sensor) and has shut down the burner output. The Zone Control (ZC) output is energized. The controller continues to monitor the system and automatically restarts if the error condition clears. Refer to Table 4–6.

The operating sequence for the L7224U is shown in Table

High Limit Controller

The High Limit opens and turns off the burner when the water temperature reaches the setpoint. The High Limit automatically resets after the water temperature drops past the setpoint and through the adjustable Differential.

Low Limit and Circulator Controller

On a temperature rise, the burner circuit breaks and the circulator circuit makes (assuming no call for heat is present) at the Low Limit setpoint. On a temperature drop of 10° F (6° C) below the Low Limit setpoint (with the adjustable Differential at the minimum setting of 10° F (6° C)), the burner circuit makes and the circulator circuit breaks. Refer to Fig. 7.

Fig. 8. Setpoints and differentials.

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

NOTE: Setting the Low Limit above the High Limit less

the High Limit Differential is not allowed as improper circulator and Zone Control functions could result.

Anti Short-Cycle Feature

The Anti Short-Cycle feature allows for field selection of a minimum delay time between burner cycles. Should a call for heat occur following the end of the previous heat cycle and before the Anti-Short Cycle delay time is expired, the circulator will be allowed to run, but the burner will be held off until the time has elapsed.

NOTE: The Anti Short-Cycle feature is blocked if DHW

demand occurs. DHW demands are serviced immediately, without any delay.

NOTE: When the Aquastat is connected to the oil pri-

mary and/or thermostat via the EnviraCOM bus, the Anti Short-Cycle time does not apply to recycle events such as loss of airflow or flame. It applies only to loss of demand.

ZR-Domestic Hot Water (DHW) Request

The ZR terminal on the L7224U can be selected to service an indirect water heater heat request. This parameter is set via the 3 digit display (see Adjusting Settings section of this document). A heat request via the ZC terminal will have priority over all other features such as the Anti-Short Cycle feature or those enabled by the Outdoor Reset Module (See form69-2235 for more information).

CHECKOUT

TROUBLESHOOTING

When attempting to diagnose system performance, reference to the LED display can help to identify specific areas not working properly. The LED display will scroll Err, followed by a digit (1-8). Refer to Table 7 for a description of each error and suggested actions and Table 8 for a troubleshooting guide.

50022037-002 OUTDOOR RESET MODULE

1 2 3 OT OT

C7089U1006 OUTDOOR SENSOR

SENSOR

LINE

VOLTAGE

CIRCULATOR

LINE

VOLTAGE

OIL BURNER

RELAY

(HOT)

LINE

Put the system into operation and observe at least one complete cycle to make sure that the controller operates properly. See TROUBLESHOOTING section to use LED to assist in determining system operation.

OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR.

M32022

Fig. 9. L7224U single zone connections.

7 69-1720EFS—03

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

LINE VOLTAGE INDIRECT

LINE

TANK AQUASTAT

INDIRECT TANK CIRCULATOR

M31462

L1 50022037-002 OUTDOOR RESET MODULE

1 2 3 OT OT

C7089U OUTDOOR SENSOR

SENSOR

LINE

VOLTAGE

CIRCULATOR

LINE

VOLTAGE

OIL BURNER

RELAY

Fig. 10. L7224U single heat zone with indirect water

tank and circulators. Optional outdoor reset module.

(HOT)

OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR.

Table 3. L7224/L7248 Controller Operating Sequence.

Action System Response

Thermostat calls for heat.

Boiler temperature exceeds the High Limit.

Thermostat is satisfied.

Boiler temperature drops below the Low Limit setting minus the differential (if applicable).

Error conditions 1-5.

Error condition 6.

Error condition 7.

Error condition 8.

Error condition 9*.

Error condition 10*.

Error condition 11*.

* Error condition only available when the Outdoor Reset

Module is installed.

Circulator starts when water temperature is above Low Limit setting (if applicable). Boiler temperature is checked. Burner starts when water temperature is below High Limit setting, less differential. If Anti-short Cycle Time is enabled, the burner does not start until the set Antishort Cycle Time between cycles expires after the previous call for heat was satisfied.

Burner is turned off. Burner restarts when the water temperature drops below the High Limit setting minus the Differential.

Circulator and burner turn off.

Burner is turned on, Circulator is turned off. Burner stops when the water temperature exceeds the Low Limit setting. Power to Zc is removed.

If an error condition is detected, all outputs except ZC are shut down. Burner is off. The controller continues to function and restarts when error is corrected. During the error check sequence, the system checks for drift in the sensor and corrosion in the connections.

EnviraCOM communication is not available.

The controller has reset the High Limit, Low Limit and Differential Setting to a default setting and will continue to run at those settings. Performance of the system will be degraded.

If the error condition is detected, all outputs except ZC are shut down. Burner is off.The controller continues to function and restarts when all three user keys have been pressed longer than 60 seconds.

System continues to run with no outdoor reset functionality

System continues to run with outdoor reset parameters enabled as programmed. Error cleared automatically.

System continues to run with boiler temp set to High Limit.

69-1720EFS—03 8

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

Table 4. L7224 Controller Operating Sequence with

multiple zones connected through the ZR terminal

Action System Response

Zone Request (ZR) terminal is connected to L1 (Zone calls for heat).

Boiler temperature exceeds the High Limit.

Zone Request input is de-energized (Zones are satisfied).

Boiler temperature drops below the Low Limit setting minus the differential (if applicable).

Boiler temperature is checked. Burner starts when water temperature is below High Limit setting. Anti Short-Cycle Time is applied, see Table 3.

Burner is turned off. Burner restarts when the water temperature drops below the High Limit setting minus the Differential.

Burner turns off.

Burner turns on and Zone Control is de-energized. Burner turns off and Zone Control is re-energized when the water temperature exceeds the Low Limit setting.

Table 5. Controller Operating Sequence with External

Low Limit device connected trough the ZR terminal.

Action System Response

Zone Request (ZR) terminal is connected to L1 (External Low Limit call for heat).

Boiler temperature exceeds the High Limit.

Zone Request input is de-energized (External Low Limit is satisfied).

Table 6. L7224 Controller Operating Sequence with

Domestic Hot Water connected trough the ZR

Boiler temperature is checked. Burner starts when water temperature is below High Limit setting. Circulator turns off.

Burner is turned off. Burner restarts when the water temperature drops below the High Limit setting minus the Differential.

Burner is turned off.

terminal.

Action System Response

Zone Request (ZR) terminal is connected to L1 (Domestic Hot Water calls for heat).

Boiler temperature exceeds the High Limit.

Zone Request input is de-energized (Domestic Hot Water is satisfied).

Boiler temperature is checked. Burner starts when water temperature is below High Limit setting.

Burner is turned off. Burner restarts when the water temperature drops below the High Limit setting minus the Differential.

Burner is turned off.

9 69-1720EFS—03

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

WARNING

Table 7. LED Error Codes.

Aquastat

Error Code Cause/Action

EnviraCOM

Alarm

Err1 Aquastat sensor fault; check water sensor. 18 Err2 ECOM fault; check EnviraCOM™ wiring. 18 Err3 Excessive electrical noise or frequency out of range. Hardware fault; replace controller. 18, 58 Err4 B1 fault; check B1 wiring/voltage. 64 Err5 Low Line; check L1-L2, 110 Vac. 59

Err6

Warning: Fuse; check ECOM wires, replace fuse. 92

Err7 Warning: EEPROM, HL, LL, Hdf, Ldf; reset to default values. N/A

Err 8

Err9

Err 10

Err 11

Repeated B1 fault (voltage present at B1 when output is turned off); check B1 wiring/voltage. 25

Warning: Outdoor Reset System failure; communication to Outdoor Reset Module lost, Outdoor Reset Module failure, multiple outdoor temperature sensors detected on the bus, or outdoor temperature sensor failure. Check EnviraCOM wiring (1, 2, 3), check sensor wiring.

Warning: Boost Failure; Boost Mode active at least once per cycle for the last 60 consecutive cycles. Check Outdoor Reset curve settings.

DHW Module/Sensor failure; communication to DHW Module lost, DHW Module failure, or temperature sensor failure. Check EnviraCOM wiring (1, 2, 3), check sensor wiring.

Warnings are generated to enunciate the system is not operating optimally, but the Aquastat is still operating and maintaining boiler temperature. In the instance where an Outdoor Reset Module is used, the warnings may indicate a reset curve setting error one or more features is not running optimally, and the Aquastat is reverting to default settings or has stopped running the Outdoor Reset algorithms. The warnings are cleared when the issue(s) is resolved.

To clear Err 8 condition, depress and hold all three user keys simultaneously for 60 seconds. Err 8 condition clears and display returns to normal. Err 8 condition is designed to catch welded relays on the Aquastat and will normally only occur near end of life for the control. If Err 8 condition has occurred early in the controls life, be sure to check for voltage feedback to B1 when B1 should be off and check current draw on b terminal to be sure burner is not drawing excessive current. Err 8 condition will keep repeating if B1 fault is not cleared.

50, 53, 149

150

146, 147, 148

Electrical Shock Hazard. Can cause severe injury or death.

All circuits must have a common disconnect to prevent the possibility of electrical shock.

69-1720EFS—03 10

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

Table 8. Troubleshooting Guidea.

System Condition Diagnostic Condition Check Action

Boiler is cold, house is cold.

Boiler is hot, house is cold.

Boiler is hot, no hot potable water

Refer to Fig. 7 for Display and LED locations.

ZC LED ON indicates ZC terminal power is OFF.

ZC LED OFF indicates ZC terminal power is ON.

Display is OFF. 120 Vac system power. Turn system power on. Display is ON.

TT-LED is OFF. Display is ON.

TT-LED is ON. B1 LED is ON.

Display is ON. TT-LED is ON.

Display is ON. TT-LED is ON. C1 LED is ON.

Display is ON. TT-LED is ON. C1 LED is OFF.

ZC LED is ON Display is ON.

TT-LED is ON. ZC LED is OFF

24 Vac T-T. No 24 V; replace controller.

24 V present; disconnect thermostat, short T-T.

120 Vac at B1-B2. • If no, replace controller.

Boiler starts, check wiring and thermostat.

• If yes, check burner and wiring.

Refer to Err on display. —

120 Vac at C1-C2. • 120 Vac at C1-C2, check

Boiler below the Low Limit temperature, wait for boiler to go above Low Limit temperature.

Boiler above LL? If yes, check for 120 Vac between ZC and L2.

wiring to pump.

• Wiring ok, is pump running? If not, replace the pump.

• If pump is running, check for trapped air or closed zone valves.

—

• If no 120 Vac, replace controller.

• If yes, check zone relays, circulators and wiring.

•

11 69-1720EFS—03

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

LINE

M17777D

SENSOR

LINE

VOLTAGE

CIRCULATOR

LINE

VOLTAGE

OIL BURNER

RELAY

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

CONTROL CASE MUST BE CONNECTED TO EARTH GROUND. USE GROUNDING SCREW PROVIDED.

L1 (HOT) L2

ZONE 2

LOW VOLTAGE

THERMOSTAT

LOW VOLTAGE THERMOSTAT

R845A RELAY ZONE 2

ZONE 2

CIRCULATOR

TO ADDITIONAL R845A RELAYS FOR OTHER ZONES

L7224

Fig. 11. L7224U multizone system with circulator connections.

69-1720EFS—03 12

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

M32024

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

OPTIONAL FEATURE ON SELECT MODELS.

REFER TO DEVICE LABEL FOR WIRE COLOR CODE.

VALVE IS OPTIONAL ON SPECIFIED MODELS.

ENVIRACOM™ TERMINAL 3 IS ALSO THE FIRST THERMOSTAT TERMINAL.

LINE

SENSOR

LINE

VOLTAGE

CIRCULATOR

L7224

BURNER MOTOR

IGNITOR

VALV E

BURNER MOTOR

IGNITOR

VALV E

CAD CELL

JUNCTION BOX

TO REMOTE ALARM CIRCUIT

ENVIRACOM™ TERMINAL

R7184

LIMIT

CAD CELL

L1 (HOT)

LEGEND SCREW TERMINAL 1/4 IN. (6 MM) QUICK CONNECT TERMINAL

SOLDERLESS WIRE CONNECTION

OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR.

OPTIONAL DOMESTIC HOT WATER MODULE.

WIRE ONLY THE ENVIRACOM TERMINALS (1, 2, 3) ON OIL PRIMARY IF CONNECTING TO REMOTE DIAGNOSTICS, OTHERWISE CONNECT A JUMPER BETWEEN THE TT TERMINALS.

ZONE PANEL TERMINALS MAY HAVE DIFFERENT LABEL. CHECK PANEL MANUFACTURER SPECIFICATIONS FOR WIRING INSTRUCTIONS.

1 2 3 TS TS

32003971-003 TEMPERATURE SENSOR

50022037-002 DOMESTIC HOT WATER MODULE

MULTI-ZONE REP LAY PAN EL

T T

1 2 3 OT OT

C7089U OUTDOOR SENSOR

50022037-002 OUTDOOR RESET MODULE

applications).

Fig. 12. L7224U multizone system with Outdoor Reset and Domestic Hot Water Modules (indirect tank

13 69-1720EFS—03

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

M32025

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

OPTIONAL FEATURE ON SELECT MODELS.

REFER TO DEVICE LABEL FOR WIRE COLOR CODE.

LINE

SENSOR

LINE

VOLTAGE

CIRCULATOR

L7224

BURNER MOTOR

IGNITOR

VALV E

BURNER MOTOR

IGNITOR

VALV E

CAD CELL

JUNCTION BOX

TO REMOTE ALARM CIRCUIT

ENVIRACOM™ TERMINAL

TH9421C

R7184

LIMIT

CAD CELL

L1 (HOT)

LEGEND SCREW TERMINAL 1/4 IN. (6 MM) QUICK CONNECT TERMINAL

SOLDERLESS WIRE CONNECTION

VALVE IS OPTIONAL ON SPECIFIED MODELS.

ENVIRACOM™ TERMINAL 3 IS ALSO THE FIRST THERMOSTAT TERMINAL.

OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR.

DUU MUST BE SET TO “ON” ON THE AQUASTAT.

1 2 3 OT OT

C7089U1006 OUTDOOR SENSOR

50022037-002 OUTDOOR RESET MODULE

INDIRECT TANK CIRCULATOR

LINE VOLTAGE INDIRECT TANK AQUASTAT

Fig. 13. L7224U single zone system with circulator, indirect water tank and EnviraCOM™ thermostat.

69-1720EFS—03 14

MATERIAL SAFETY DATA SHEET

L7224U OIL ELECTRONIC AQUASTAT® CONTROLLER

Section 1. Product And Company Identification

Product Name: Heat Conductive Compound

MSDS ID: DS9021

Synonyms: MS1699

Product Use: Heat conductive material used to enhance contact and heat transfer in temperature sensor applications.

Manufacturer: Honeywell Inc. 1985 Douglas Drive North Minneapolis, MN 55422.

Date Released: October 8, 1999

Customer Response Center: 800-328-5111

Emergency Telephone Information: 888-809-3787

NFPA Ratings:

Health 0; Flammability 1; Reactivity 0; Personal Protection B

Section 2. Composition, Information on Ingredients

Ingredient CAS Number Percent PEL TVL

#2 Lithium Complex Grease (70%): Mineral Oil 64742-65-0 35-50

Mineral Oil 64742-62-7 20-25

Lithium Hydrostearate/Sebacate Complex

Zinc Alkyldithiophosphate 68649-42-3 0-2 — — Aluminum Paste (30%): Aluminum, as Al 7429-90-5 20-25

Aliphatic Petroleum Distillates 8052-41-3 10-15

Stearic Acid 57-11-4 1-2 — — Aromatic Petroleum Distillates 64742-95-6 1-2

Additional Information: Part No. 120650 (0.5 oz tube); Part No. 107408 (4 oz can); Part No. 197007 (5 gallon

container). May also contain minute amounts of lithium and molybdenum lubricant compounds.

68815-49-6 4-9 — —

5 mg/m

15 mg/m

2900 mg/m

5 mg/m

10 mg/m

525 mg/m

5 mg/m

Section 3. Hazard Identification

Acute Health Effects:

Skin: Excessive contact may cause skin irritation and dermatitis.

Eye: Direct contact with eye will cause irritation.

Inhalation: No adverse effects are expected.

Ingestion: Ingestion of product may cause nausea, vomiting and diarrhea.

Chronic Health Effects:

Existing skin rash or dermatitis may be aggravated by repeated contact.

OSHA Hazard Classifications: None.

Carcinogenicity: Not considered to be a carcinogen by either OSHA, NTP, IARC, or ACGIH.

Section 4. First Aid Measures

Eye Contact: Flush eyes with water for 15 minutes. Remove any contact lenses and continue to flush. Obtain medical attention if irritation develops and persists.

Skin Contact: Remove excess with cloth or paper. Wash thoroughly with mild soap and water. Obtain medical attention if irritation develops and persists.

Ingestion: Contact physician or local poison control center immediately.

Inhalation: Remove patient to fresh air and obtain medical attention if symptoms develop.

Section 5. Fire Fighting Measures

Material Flash Point: > 383° F (195° C). Will burn if exposed to flame.

Extinguishing Media: Carbon dioxide, dry chemical or foam.

Special Fire Fighting Procedures: None.

Explosion Hazards: None. Aluminum powder can react with water to release flammable hydrogen gas. In the form of this product, this reaction is not expected.

15 69-1720EFS—03

+ 33 hidden pages

Honeywell L7224 Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual