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steam pressure almost 30!?

I have a Peerless EC-03 steam boiler installed about 7 years ago by a steam pro. He did an excellent job of piping it and he even correct the hot hot water loop which was constantly air bound.( about 25 ft of fin baseboard heat on the 1st floor) He installed a spiro vent and I finally had heat from my baseboards. (Not enough heat but my house is under insulated)

About 2 years ago during a remodel and floor replacement I asked him to replace the baseboards in my den (20' X 16') with radiant underfloor heat. He stapled the tube (about 300ft x2 loops to plywood (vapor barrier & plenty of insulation underneath plywood) filled in with sleepers (3/4) and it was covered with 3/4" wood flooring. It's constantly air bound. My pro is no longer working in the business.

Yesterday I tried to take matters into my owns hands.

I pumped up the T-stat and tried manipulating the valves to get hot water into the tubing.

Since I generally blow down my boiler every two weeks I proceeded to do that at the same time.

I filled a 5 gallon bucket but the boiler did not shut down on low water. I slowly started to add water back. The 30lb pressure gauge rose to about 27 or 28. I watched it run for a while so that the fresh water would boil and then I blew it down again. This time the boiler shut off on low water but the pressure was still 28. I replaced the water, boiled it and shut the boiler off. The pressure went to about NEGATIVE 20. I let everything cool down and in about 3 hours the gauge went back to zero. I removed the pressure trol (didn't test it) and flushed the pigtail. There was black water but no solid gunk. I tried to flush the MM low water cutoff. After putting it back to together I started it up again and the pressure was about 15 went I shut it down and it went negative again. Afraid to run it without a pro looking it over.

My fuel oil company will come to look in a few days (service contract) but they said they have never seen a steamer at 27 (?) and it must be a defective gauge. I think pressure trol or expansion tank. Not sure what my tinkering with the hot water loop had to do with pressure rise, if anything. And of course they can't help with the air locked loops. I need a pro on south shore of western Long Island. Willing to wait (with heat off) because I realize there are people with no boilers and no homes and much much bigger problems than me. Just concerned with safety. don't know anyone in my area who is good with steam and of course I'd like to get hot water loops working.


  • conversiontime
    conversiontime Member Posts: 87
    no liftoff??

    sorry, could not help it! But it the pressure really was 30, you would have major steam blowoff occurring. Low pressure steam boilers are designed to blow the emergency release at around 15 psi which should shut down the boiler. Even if that failed, you would have steam screaming from every radiator vent and valves at 30psi.

    Still very wise to get a pro in to look, you can also install a low pressure gauge on the boiler to get a better idea of its pressure.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    You don't suppose...

    the valve might be plugged?
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • eclark
    eclark Member Posts: 33
    Did you futz with the pressuretrol?

    While you were adjusting the valves around?  What's it set at now? 

    If you haven't already, try pulling it off the pigtail and checking for clogs there.  I just had a similar problem where my pigtail was clogged, the pressuretrol wasn't working anyway and my pressure relief valve had failed.  I was getting 27-28psi at the boiler and it would only turn off when the thermostat quit calling for heat.  I did end up having a screaming steam leak at a union, but I wasnt' anywhere near it when the system was running.  I only found it when I went out looking for it.  New pigtail, new (slightly used) pressuretrol and new pressure relief valve and I'm up and running right where I want to be.
  • Steve_95
    Steve_95 Member Posts: 27
    thanks for the replies

    I appreciate the replies because my heat is off since Sunday and my Oil Co. serviceman is busy with the aftermath of Sandy.

    Last night after cleaning the pigtail for the 3rd time I started the boiler and the gauge was reading 29psi within 20 minutes. It then started to slowly drop down to 5psi. My boiler normally runs at less than 2psi.

    It never shut down on pressure and the relief valve never blew. I got up at 4AM today (because its getting cold in the house) and ran thru the same scenerio: 28-30 psi...after an hour or so dropped down to about 5psi. Appreciate any help. IS there a good steam man available for South Shore LI? My oil guy is good for service but I want a steam pro. There is no one on Find a Contractor.
  • conversiontime
    conversiontime Member Posts: 87
    edited November 2012
    try another gauge


    Since you can remove the pigtail with the gauge, go ahead and replace the 0-30 psi code gauge and test again. I suspect the current gauge is shot and is giving inaccurate readings. Hopefully you should be able to find a 0-30 psi steam gauge locally since they are code required and can make the switch today. A 0-3 psi gauge would also be a great idea later but for now see if you can find 0-30 replacement gauge. You will also need some teflon tape or pipe dope for the threads.
  • jumper
    jumper Member Posts: 2,245
    I don't understand

    I don't understand what steam has to do with your water heated floor. How is that water tempered ? Heat exchange or blended ? The spiro vent has to be at a low pressure to get air out.

    I used to use an air powered ejector for stubborn air.
  • Steve_95
    Steve_95 Member Posts: 27
    help may be on the way...

    Sorry guys... re-reading my original post I can see how confusing and "all over the place" it is. Should have left the hot water loop for a different thread. I'll get to that once I get the steam under control.

    To Conversiontime: thanks for your help. My 30psi gauge is not on a pigtail. It has what looks like 1/4 thread which is threaded into a bushed down 3/4" tap in the face of the boiler.

    Not sure I want to put a wrench to my boiler with my "heavy hand" if you know what I mean.

    My Oil Service Man will "try" to get to me tomorrow, hopefully with a new 0-30 gauge.

    I hope you're right about the gauge being no good. If the pressure was that high (28psi) wouldn't the reliefs blow or wouldn't the p-trol shut it down?

    Will definitely be adding a 0 to 3 gauge after this episode.

    Jumper: sorry for confusing things. The steam of course has nothing to do with my hot water loop problem. The hot water is piped with sort of a loop to blend the return water with the water going out to the baseboards and radiant. I guess I'll need a good hydronics man in addition to the steam expert. Anyone want to take this on?

    Thanks for the help. I'll report back after the serviceman comes.
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