Jon Klima, Owner
360 Trout Lane, PO Box 23, Guffey, CO 80820
Phone: 719 479-2281,  Email:
In business for 39 years





The Honeywell R7412B is a basic ON/OFF digital differential temperature controller from the late 1970s and early 1980s used for automatic control of circulation pumps, valves, dampers, motors and other accessories used in solar energy systems. This controller provides the temperature differential function along with recirculation freeze protection capabilities. The differential temperatures are factory set at 18º/3º F but can be programmed to anywhere from -10 ºF to 40 ºF by changing out the "R-ON" and/or the "R-OUT" resistors on the PC board.


The recirculation freeze protection provided by this controller is factory set at 37 ºF. When the collector sensor drops below this temperature, the controller gives an output to start the circulating pump.


This controller uses Honeywell specific C773 positive temperature coefficient sensors. Click here to see the C773 sensor specifics.


Click here to see the complete Honeywell Specifications sheet.


If you are looking to replace your defective Honeywell R7412B controller or just want one as a backup, order this one today as it is the only one left. Prices shown do not include postage.  Colorado sales will be charged the appropriate sales tax. Yes, I accept credit card payments through PayPal, checks, and money orders.  For questions or to place an order, send me an email (see top of this page) stating what you are interested in along with your zip code.  I'll check the postage to your zip code and send you a return email with the total cost.



Back to the CSC "Used Controllers 4 Sale" page.


This page was last changed on 4-29-2015