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About Vaporstat install

RobLC
RobLC Member Posts: 93
in THE MAIN WALL
Currently, we have a P404A Honeywell Pressuretrol. This units differential settings are 1 to 5 lbs. It is single phase, has one black wire and one red wire coming from the on/off switch for the boiler. The boiler is an old gas-fired steam boiler.

The current settings are .5 for the cut-in and almost 1.5 (more like 1.3) for the differential.

We would like to install a Vaporstat.

What would be the best model and settings, e.g., Honeywell model ? and cut-in ounces and differential, cut out?

Thank you.

Comments

  • Abracadabra
    Abracadabra Member Posts: 1,948
    L408J1009

    settings vary depending on your situation, but I like to start at about 12 oz with a 8 diff
  • RobLC
    RobLC Member Posts: 93
    Ok, thank you for the info. Then we'll try 12oz and 8oz. This would mean that Vaporstats are subtractive?

  • Abracadabra
    Abracadabra Member Posts: 1,948
    yes.. the 2nd setting is a subtractive differential. So 12oz with 8oz diff setting means off at 12oz and on at 4oz

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