Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Pressurtrol hanging up --Repairable?

mel rowe
mel rowe Member Posts: 324
Thanks for the reply. The Pressurtrol is a Honeywell PA404A (additive differential) type. It is about 18 years old.

Comments

  • mel rowe
    mel rowe Member Posts: 324


    The pressurtrol on my steam boiler is shutting off on the cut-out setting of 1.5 lbs. but does not cut in at .5 lbs. It seems to be hanging up. When I just touch the lever inside, it cuts in okay. Since this is the weekend, is there a way I can possible fix it? I see white residue around the diaphragm area inside. If this is the problem, can I boil it in vinegar water and clean it out? Thanks.
  • What brand and model number ?

    We had a bad batch of PA404s that did exactly what you describe , on new installs . The boiler would cycle once on pressure , then wouldn't come back on unless we raised the cut out and diff settings . We switched to the Honeywell mercury controlled pressuretrols and they work excellent . If you have a mercury control , make sure the level arm inside the control matches up with the hash mark . And the pigtail orientation has to be a certain way - the twist on the pigtail heats up and turns and can affect the reading .
  • Rich Ferris
    Rich Ferris Member Posts: 72
    Do you check the pigtail?

    > The pressurtrol on my steam boiler is shutting

    > off on the cut-out setting of 1.5 lbs. but does

    > not cut in at .5 lbs. It seems to be hanging up.

    > When I just touch the lever inside, it cuts in

    > okay. Since this is the weekend, is there a way

    > I can possible fix it? I see white residue

    > around the diaphragm area inside. If this is the

    > problem, can I boil it in vinegar water and clean

    > it out? Thanks.



  • Rich Ferris
    Rich Ferris Member Posts: 72
    Do you check the pigtail?

    The pigtail could be clogged up. Remove it, blow through it. If it's clogged up you can stick a coat hanger end through it then clean it out. After you reinstall it put water in it to protect the control. It will seek it's own level. Good luck.

    Rich
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    I too...

    Suspect that the "pigtail" is plugged.
    AS Ron said, the orientation of the pigtail should be at a 90° angle to the boiler block.If you have a mercury control, this is WAY important. Chris
  • mel rowe
    mel rowe Member Posts: 324


    I cleaned out the pigtail recently. It was pretty well clogged up. I filled with water when I replaced. This Pressurtrol doesn't have a mercury switch. I suspect it has a diaphragm that moves with the pressure and in turn moves a metal lever that actuates the on/off cycle. That's the area that looks like it has a whitish build-up around it that I wondered about cleaning by placing the lower part of the pressurtrol in a boiling water/vinegar solution.
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    Well....

    Sounds like the diaphram has failed in the pressuretrol and it's time for replacement.

    Don't mess with it...either get someone to replace it or shut it down. This is a safety issue and NOT something that should be taken lightly.Make sure the pigtail is cleared upon replacement, and proprly aligned. Chris
  • mel rowe
    mel rowe Member Posts: 324


    Sounds like the ideal time to switch from a pressuretrol to a vaporstat, like the one someome here gave a link for-the Honeywell L408J. In switching from the Pressuretrol PA404A (additive differential) to the vaporstat, which one would be the correct part number among the several alternatives in this link? http://customer.honeywell.com/Techlit/pdf/65-0000s/65-0287.pdf Thanks a ton for the help.
This discussion has been closed.