From NEPA Crossroads Knowledge Base
Some lookup information for Honeywell Aquastats & Boiler Controllers
The primary differences between the suffixes are integrated circ control and ability to run zone valves. Numbers after the suffix letters usually have to do with fixed or adjustable temp differentials, manual reset, etc. There are direct immersion, immersion well, and strap on mounting types, select whichever you need. Immersion well or strap on types allow you to change a defective unit without draining down the system. Strap on types are handy for when you do not have another port to put an immersion well in a boiler but may not be as sensative.
Honeywell is a little odd in their manuals W/R/T switching terminology. Example, they list the L4006, L4007 and L4008 series as "SPST" then say the L4006G has "two switches break simultaneously". That would be DP switching, not SP.
Aquastat Main index:
Here are the direct links to the PDF manuals for the 8124 series aquastats
(A,C,E,L,M suffix) http://customer.honeywell.com/techlit/p ... 5-6571.pdf
(B,E,G,L suffix) http://customer.honeywell.com/techlit/p ... 0-0786.pdf
L4006A - open on temp rise, SPST contacts, immersion well type
L4006B - close on temp rise, SPST contacts, immersion well type
L4006E - non-immersion well, SPST contacts pipe mountable version of L4006A
Dual Purpose Aquastats (circulator and limit control):
Other Dual Purpose aquastats:
L4008x DPST and L6008x DPDT