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High Limit Stop on Honeywell Aquastat

JohnK Member Posts: 7
edited November 2018 in Gas Heating
I have a Honeywell L8148E High Limit Aquastat.

I recently noticed that there is a "stop" that sits right on top of the dial face. The stop appears to be set at 160 . If I am reading the manual correctly, would this stop prevent the boiler from reaching 180F water? My goal is to set the aquastat to 180F.


  • Leon82
    Leon82 Member Posts: 684
    edited November 2018
    That looks like a little saftey feature that makes it hard for anyone to just crank the dial too far who is not experienced.

    They actually have those in foucets and shower valves now too.

    So it looks like you can move it to 180 if you wish.
  • JohnK
    JohnK Member Posts: 7
    I did adjust the safety dial from 160 to 180.

    Now, the boiler water finally gets much hotter!
    HVACNUT Member Posts: 5,038
    That's typical of the L8148.
    They usually come set at 180. The "A" control for oil anyway.
    Easy to adjust to 180 but why? Leave it at 160. That's probably more than needed.
  • JohnK
    JohnK Member Posts: 7
    edited November 2018
    @180F, the cast iron radiators (hot water) have a surface temperature of 150F. Is this too hot?

    The house feels much more comfortable.