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Homeowner Question on Steam Pressure Gauge

Mark K
Mark K Member Posts: 26

I have a gas-fired One-Pipe Steam system. Last August, I had the local gas company come to service/tuneup the boiler. The tech reported that everything was in good working order.

I just turned on the system for the first time last weekend. Everything seems fine. The radiators on the first floor were cranking within 10 minutes of the boiler turning on, and the ones on the second floor also heated up nicely soon after. There was no water hammer noise, and there was just a slight "whooshing" sound from some of the air vents on the radiators.

I went to the boiler to take a look at things while it was running. The gauge glass was 3/4 full of rusty water, but it was gently rising and falling in the glass; no splashing or bubbling.

So here is the question. I looked at the pressure gauge and it was reading 5 psi. The pressuretrol is set for cut-in at .5 with a 1 differential. Given that the house heated up quickly, with no noise and no problems, should I be concerned about this? I looked at the dial three times, to make sure I wasn't misreading it.


  • Fred Harwood
    Fred Harwood Member Posts: 261

    One-pipe steam should work well with less than one psi. Five psi sounds high, and unnecessary. Consider installing a Vaporstat to regulate pressure under one psi.

    If your gauge returns to zero, the gauge probably is OK, and the pig tail not plugged.
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