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L7224U OIL ELECTRONIC AQUASTAT

®

 CONTROLLER

69-1720—03

2

INSTALLATION

When Installing this Product...

1.

Read these instructions carefully. Failure to follow 
them could damage the product or cause a hazard-
ous 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.

WARNING

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.

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

1.

Turn off all power and drain the boiler.

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.

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.

M22147B

3/4

(75)

5-11/16

(145)

3/8

(10)

2-5/8 (67)

7-1/8

(181)

6-1/2

(166)

3-13/32 (86)

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

1/16 (2)

1-3/16

(30)

3-1/32

(77)

2-1/16 (53)

1-1/8 (29)

4-1/4 (109)

Summary of Contents for Aquastat L7224U

Page 1: ...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 ...

Page 2: ... 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 averag...

Page 3: ...f 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 Fig 3 Position of sensor...

Page 4: ... 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 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 L72...

Page 5: ...econds Press the I button until the feature requiring adjustment is displayed 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 m...

Page 6: ...t 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 Boiler Temperature Description Display Shows High Limit Differential Low Limit L7224 only Low Limit Differential L7224 only Local Thermostat Status EnviraCOM Thermostat Status Boost Step Warm Weather Shutdown Temp...

Page 7: ...mand 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 2...

Page 8: ...with outdoor reset parameters enabled as programmed Error cleared automatically Error condition 11 System continues to run with boiler temp set to High Limit 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 is checked Burner starts when water te...

Page 9: ...leared WARNING Electrical Shock Hazard Can cause severe injury or death All circuits must have a common disconnect to prevent the possibility of electrical shock 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 ...

Page 10: ...y is ON TT LED is ON B1 LED is ON 120 Vac at B1 B2 If no replace controller If yes check burner and wiring Display is ON TT LED is ON Refer to Err on display Boiler is hot house is cold Display is ON TT LED is ON C1 LED is ON 120 Vac at C1 C2 120 Vac at C1 C2 check 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 Displa...

Page 11: ...ING SCREW PROVIDED 2 3 L1 HOT L2 1 2 1 4 5 6 ZONE 2 LOW VOLTAGE THERMOSTAT R845A RELAY ZONE 2 ZONE 2 CIRCULATOR TO ADDITIONAL R845A RELAYS FOR OTHER ZONES C1 B1 ZC L2 LINE C2 ZR L1 B2 T T 3 2 1 SENSOR LINE VOLTAGE CIRCULATOR LINE VOLTAGE OIL BURNER RELAY 2 LOW VOLTAGE THERMOSTAT L7248L ENVIRACOM TERMINALS OPTIONAL OUTDOOR RESET MODULE AND OUTDOOR SENSOR SHOWN 3 4 1 2 3 OT OT C7089U OUTDOOR SENSOR ...

Page 12: ... 2 2 2 1 1 1 SENSOR LINE VOLTAGE CIRCULATOR L7224 3 4 3 3 5 BURNER MOTOR IGNITOR VALVE BURNER MOTOR IGNITOR VALVE CAD CELL JUNCTION BOX TO REMOTE ALARM CIRCUIT ENVIRACOM TERMINAL TH9421C R7184 LIMIT L1 L2 2 CAD CELL T T3 2 1 L1 HOT L2 1 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 TH...

Page 13: ... lubricant compounds 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 ...

Page 14: ...gles or faceshield if potential for eye contact exists especially if material is heated Hand Clothing Protection Not normally required Protective gloves and clothing are recommended as material is difficult to remove from skin and clothing Other Protective Equipment None required Section 9 Physical and Chemical Properties Appearance Odor Aluminum color semi solid material pleasant odor Solubility ...

Page 15: ...L7224U OIL ELECTRONIC AQUASTAT CONTROLLER 15 69 1720 03 ...

Page 16: ...olutions Honeywell International Inc Honeywell Limited Honeywell Limitée 1985 Douglas Drive North 35 Dynamic Drive Golden Valley MN 55422 Toronto Ontario M1V 4Z9 customer honeywell com U S Registered Trademark 2009 Honeywell International Inc 69 1720 03 M S Rev 08 09 ...

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