Download the manual for a Honeywell Aquastat from ManualsLib.com. The manual contains detailed installation instructions for the unit, along with diagrams of the unit's components. ManualsLib.com contains manuals for the Aquastat L8124A and L8148A units.
The manuals contain diagrams that show how the Aquastat should be positioned in the immersion well. Internal schematics that show single zone and internal connections are also available. Further schematics show how the Aquastat fits into multizone systems and oil-fired pump systems.
Basic operating instructions are listed at the end of the manual. The instructions cover the unit's high and low limits, and give advice on setting them. Further information regarding the reset button and temperature limits is available at InspectaPedia.com. The series of articles is aimed at helping users troubleshoot the unit and carry out diagnosis and repairs.
InspectaPedia.com contains detailed instructions for finding and using the Aquastat's reset button, along with setting the control sequence and operating the boiler. The Aquastat's differential function has its own section in the article, which discusses how to find the best differential settings for the unit and gives some rules of thumb.
The final section of the Inpectapedia.com article explains how to set the large and small dials and how each setting changes the unit's behavior.