Which vaporstat

Luv'nsteam

In looking up a part number for the Honeywell vaporstat, L408J, I see there are two sub numbers.  One has a SPST switch (L408J1025) and the other has a SPDT (L408J1009).  I didn't notice any other differences (are there?). 



For my one-pipe vapor steam heating system, which one do I want?



Thank you,



Mike

Unknown

L408J Vaporstats

Hi Mike- Here's some info on Vaporstats for you.

- Rod

Luv'nsteam

Vaporstat choice

Hi Rod, thanks for the PDF's.  After looking at them, I think I want the SPDT vaporstat.  I think this because the vaporstat, LWCO (float) and LWCO (probe) will be wired in series.  The L408J1009 has the SPDT switch and breaks contacts R/B on rise, where the SPST only makes on rise.  SInce I am using the vaportstat to shutdown the boiler on pressure rise, and only the 1009 vaporstat breaks on rise, this is the model I want, correct?



Thank you,



Mike

Steamhead

Yup

you'd use the other one to shut off the burner if the pressure fell. The 1009 is the one you want.

Luv'nsteam

Much appreciated

Steamhead and Rod, many thanks to both of you for your help.



Have a great week,



Mike