L7224U OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT
7-1/8
(181)
6-1/2
(166)
5-11/16
(145)
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
settings 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 instal-
lation 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.
69-1720EFS—13
3/4
(75)
2-5/8 (67)
4-1/4 (109)
Fig. 1. L7224U mounting dimensions in inches (mm).
®
CONTROLLER
3/8
(10)
3-13/32 (86)
2x 1/4 (7) x 3/8 (9)
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.
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.
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.
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
2
1-3/16
(30)
2-1/16 (53)
1/16 (2)
3-1/32
(77)
1-1/8 (29)
M22147B