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Can I replace this pressuretrol with a vaporstat

The pressuretrol on my boiler seems to be faulty.  Cuts out if I set pressure below 2psi and does not come back on.  Also starts clicking and then boiler goes off and comes back on several times. 

1. Should I replace with a vaporstat instead of a pressuretrol?

2. What are the positives and negatives of replacing with vaporstat?

3. Can any competent plumber install a vaporstat or does it take expertise with steam?

Here is a picture of the pressuretrol and thanks to Todd ECR a manual for the boiler (which obviously does not answer the question).

Sears Roebuck and Co

Series 2D512

Boiler Model No 229 96165

Serial # 760 3478

Input BTU per he 174000

Output BTU per hr 139200


  • Steamhead
    Steamhead Member Posts: 16,888
    Check the pigtail under the pressuretrol

    the loop in the piping. With the control acting like that I'd bet it's plugged. If the pigtail is brass, it can be cleaned. If it's steel, replace it with a brass one. 
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Bullethead
    Bullethead Member Posts: 21
    Three questions hoping for answers.

    Thanks for the suggestion on pigtail.  I will see if I can resolve that.

    But does anyone have an opinion on the three questions I have posed regarding pressuretrol vs vaporstat?  Are these questions more complicated that I think?
  • BobC
    BobC Member Posts: 5,479

    The right vaporstat will allow the boiler to run in a lower pressure range IF the pigtail is clear and the port into the boiler is also clear. It usually is not worth replacing a working pressuretrol in most cases but if your going to have to install a new one it's probably worth paying extra for the vaporstat.

    All you have to do is unwire the old one (after disconnecting the power), twist it off and twist on the new one (and wiring it up). make sure pipe dope or teflon tape is used on the plumbing connections.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • vaporvac
    vaporvac Member Posts: 1,520
    Add to, not replace...

    The Vstat doesn't replace the pressuretrol, but is in addition to it. The 0-30 pressuretrol is a safety device required by code. I have heard of no downside to using a Vstat, although I would get the o-16oz one.

    Someone else will have to comment on the difficulty of setting one up. I couldn't imagine it's much more than reading the instructions, but from my experience that's often asking alot. You could certainly get the brass bits required to attach it and I would encourage you to add brass unions to all your controls to make clean out of the pigtails easier. I would put a Vstat on its own pigtail and maybe put a shut-off valve to protect it if you do higher pressure blowdowns. Most installers wouldn't go through the extra effort to provide these small things. C
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF