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.

Boiler sluggish, Safety Valve went off!

Hello, I purchased a Home in Queens in 2009. (Built 1939) with a new Burnham boiler (Gas/Steam 1 Pipe) installed 2007. It seemed properly installed as per Dan's Steam Night Class. About two weeks ago, my wife put thermostat to about 80'. I asked her 2 lower it (my mom complained to HOT!) (over the phone, wife refused to lower temp) When I got Home, (2 am) the LWCO kicked in and was auto feeding. I waited a few minutes, and set thermostat back to our normal 70 Degrees) Fast Forward two weeks, I do my Bi-weekly check and find out the boiler glass was overfilled (I drained in a Bucket to mid level) it had real dirty/lurky/cloudy water. Recently, (today, 3am) with the current Snowstorm, i decided to crank to 73 degrees (deviating from my normal 70) The boiler fired, but I felt it did not sound "crisp" as it usually does. I felt something was wrong (sluggish,slow boil) so I decided to read a book in the basement (just in case) To my whopping surprise, the Safety violently engaged (it burned my sheetrock!) I Immediately shut off power to system and now have no heat (with about two feet of snow outside!!)

Two weeks ago, I tightened up the radiators upstairs (some were leaking) I also replaced 1 Vent in 3rd floor bathroom and I put chess pieces in about 3 radiators throughout the house to "hopefully assist in overall system performance.

Did I do something wrong?

Should I even try to fire again?

I am flat broke and there is lots of snow outside..

Should I attempt to clean boiler (It might be dirty, glass seems mildly cloudy)

Is the safety valve still serviceable after popping up once?


  • BobC
    BobC Member Posts: 5,473
    Safety Issue

    Well I bet that got your attention!

    A safety that has popped should probably be replaced, to eliminate the possibility ther is something wrong with it. That should not pop till your above 15PSI and you should be running around 1.5PSI normally.

    Did your pressure gauge show what pressure you were working at before the safety popped?

    Take things apart so you make sure the pigtail isn't blocked, if that gets blocked with sludge (and they do) your pressuretrol cannot sense the boiler pressure. If your not comfortable doing that call someone in TODAY. This is a safety issue and should not be taken casually.

    Is your water feeder leaking? Sometimes a bit of crud prevents them from closing all the way. Do you have any idea how often the auto water feeder is turning on?

    You could try shutting the valve that feeds the auto water feeder off and monitoring it to see if your boiler level starts to drop (indicating a slow leak somewhere)

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Jamie Hall
    Jamie Hall Member Posts: 22,952
    I second Bob's remarks...

    a safety valve which opens is a sure-fire attention getter.  And will need to be replaced.  In theory, it should close again, nice and tight, and work just fine, but it is the last line of defence against some even more attention getting fireworks, so...

    That said, it is clear that the pressuretrol(s) failed to operate (you may have one or two).  That suggests rather strongly that when the boiler over filled you got crud in the pigtail(s) to the controls (and, quite possibly, to the pressure gauge).  They should be taken apart and cleaned.

    Should you try to fire again?  My advice, snow and cold notwithstanding, is no -- until you find out why the pressuretrol didn't shut things off.  If they aren't operating for some reason, the only pressure control your boiler has is that safety valve!  So try to get someone out (if you don't feel like doing it yourself) and see why they failed and get them fixed.  The same someone may be able to give you some idea as to why the boiler overfilled in the first place -- a simple long cycle shouldn't do that.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • World Plumber
    World Plumber Member Posts: 389
    Pigtail / presuretroll

    DO NOT TURN IT ON!!!!! Until you find out why the presuretroll didn't shut it down. It sounds like the pigtail is probably blocked. That needs to be checked, cleaned and tested before you turn the boiler back on. Sometimes the relief valve will freeze fast after popping. So I would suggest  replacing it.

        Other wise you are sitting on a BOMB if you run the boiler with out the repair. You could find your house in several towns if you try to use it the way it is. 
  • Shuttle
    Shuttle Member Posts: 24
    I have an idea what might have been the Problem

    Thank-You guys for the great advice. I decided to check the Pressuretol. (It was set on possibly the highest setting "8" outside dial, inside limit read 1 (It has been this way for the whole 2 Years I've lived here!) I also checked the MAIN vent (It was clogged, the Vinegar trick did not work!!!) I went to the local shop and purchased a new main (10 pounds for 24 bucks) I purchased a new safety relief valve for 12 bucks (same exact brand 15PSI) However, I could not remove the old one because the return is in the way (It wont let it turn pats half-way!

    To answer BobC's questions...The boiler read approx 18 when it "boomed"

    Did NOT check if there is leak

    Feeder cranks maybe 1/every 4-5 weeks??(that I know)

    I decided to re-crank it! pressuretol set at .5 and 1 It ran fine, It did not go past 5 PSI

    although, I am still scared at going to sleep with it on. I will wait till tommorow to re-crank it so I can monitor it for a longer period

    Any advice on getting that relief valve off?? (please see pics)

    I will try to give the pigtail a cleaning tommorow morning (to busy at work!!) I shall sleep cold tonight!!!

    Please excuse my wife's red panties in photo!!!

    So far,

    1) I drained the boiler several times (including when on) water! (still dark/cloudy)

    2)I set the pressuretol at .5 and 1 (as per Dan)

    3) I replaced main vent
This discussion has been closed.