60-2278—9 G.R. Rev. 12-01
www.honeywell.com
Automation and Control Solutions Automation and Control Solutions
Honeywell
Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North
35 Dynamic Drive
Golden Valley, MN 55422
Scarborough, Ontario
M1V 4Z9
Printed in U.S.A. on recycled
paper containing at least 10%
post-consumer paper fibers.
L8148A,E,J AQUASTAT® RELAYS
SETTING AND ADJUSTMENTS
Setting
High Limit Switch
Heating systems differ and the correct temperature setting for
one system may not be the correct setting for another. Follow
the boiler manufacturer recommendations for proper setting.
With cover off, turn the dial until the desired setting is directly
below the indicator. Models with optional dial stop can be
adjusted using a small screwdriver as shown in Fig. 15.
Fig. 15. Adjusting models with optional dial stop.
OPERATION
WARNING
Explosion Hazard.
Can cause severe injury, death or property
damage.
This product is intended for use only in systems with a
pressure relief valve.
The switching relay is controlled by the low voltage room
thermostat. On a call for heat, the relay contacts make to
complete the line voltage circulator circuit and also the burner
circuit when the boiler water temperature is below the high
limit. The high limit switch shuts off the burner if boiler water
temperature exceeds the high limit setting.
The AUTO-MANUAL switch (only L8148J millivolt models)
operates the burner during electrical power failure. With the
switch at MANUAL, the burner operates continuously until
high limit is reached or the switch is reset to AUTO. The
circulator, requiring line voltage, is inoperative. When power is
restored, reset the switch to AUTO to resume automatic
operation.
CAUTION
Equipment Damage Hazard.
Can cause equipment damage and operational
failure.
Never apply a jumper across (or short) terminals B1,
B2, or B3. This burns out the transformer.
CHECKOUT
Put the system in operation and observe through at least one
complete cycle to be sure all equipment functions as
described in the Operation section.
INSERT CORNER OF SMALL
SCREWDRIVER IN THIS
NOTCH AND PRY STOP
UPWARD FROM DIAL FACE
WHILE HOLDING STOP AWAY
FROM DIAL FACE WITH
SCREWDRIVER, TURN
DIAL UNTIL DESIRED HIGH
LIMIT SETTING IS ALIGNED
WITH POINTER
RELEASE SCREWDRIVER;
MAKE SURE HIGH-LIMIT
STOP RESTS FLAT
AGAINST DIAL FACE
POINTER
HIGH LIMIT
STOP
DIAL FACE
M8889
