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Testing a 15psi pressure safety valve on my boiler

I wanted to do a maintenance test on my new pressure relief valve installed on a Weil-McLain boiler. Its a 15psi Burnham that I purchased online. I asked the plumber to install it a few months ago when he was checking out the boiler but he said that it wouldn't be necessary to check it until heating I replaced it myself...but I don't know if it is working.

I flipped the little lever 90 degrees and then more and nothing happened. Do I need to pull on the handle?


  • ZmanZman Member Posts: 3,480

    A 15 psi boiler relief valve is an unusual item. Most residential systems have 30# T&P.

    Maybe you should post a picture. These are very important to the safe operation of the boiler.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • What I installed

    You can see the valve at the following link. Much better photos than I can take!

    A 15psi PRV was on the boiler when I inherited it. I don't have the specs for the EG-55 PRV other than being 3/4 inch.
  • ZmanZman Member Posts: 3,480

    Ah, you have steam boiler.It will not do anything until the boiler is pressurized with steam, even then there should not be much pressure involved.

    I would post a picture of your install along with the boiler rating plate in the "strictly steam" section. Those guys can check to see if it is correct.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • icesailoricesailor Member Posts: 7,265
    15# relief valves:

    Uhm, is this a steam boiler? They are rated for a maximum, of 15# PSI. The boiler has to be running and making steam when you test it.

    Maybe the "Plumber" tried to explain that to you and you didn't want to hear it.

    Post a photo of the boiler and installation. You may have the wrong relief valve for your installation.

    Are you aware that PEX Supply made more money in profit by selling that valve to you on-line and letting you  install it than I would have made if I bought it from my supplier, installed it and charged you for the valve and installation?

    "Profit" is not an obscene concept and "Overhead" is not the ceiling above you.
  • Yes its a steam boiler

    Sorry I forgot to mention that I have a steam boiler, an EG-55 probably over 20 years old. I'll check into reposting in the steam section, although your observations are very helpful but first I have to replace a bad low pressure gauge.
  • Yes its a steam boiler

    Yes its an EG-55 steam boiler.

    When the plumber fired up the boiler to check the new controls that he installed I asked him to replace a loose skimmer outlet pipe, which he did. He also cleaned up the sight glass, but he didn't want to check the safety pressure valve in case it wouldn't close and he didn't have a 15psi replacement, only a a few weeks later I replaced the valve for about $15. I'm sorry if this offends you, but it was less expensive then calling the plumber back for an $80 service call plus materials. There are a few other things he didn't properly check out and I have since replaced a three bad radiator valves and the pressure gauge that wasn't working properly even when he was working on the boiler controls.
  • got any?

    Got any pictures of the boiler... main thing as for maintence is to clean the pig tail loop every now and then... Weil McLain is a good boiler when properly piped and maintained..
  • Bob HarperBob Harper Member Posts: 732
    Hartford Loop

    The Hartford Loop should have a close nipple where it connects to the equalizer. You may be prone to water hammer with this setup.

    More pics of combustion venting?
  • not only

    Not only that, the whole near boiler pipings needs to be redone..
  • More pictures

    Is this the combustion venting that you wanted to see?
  • gennadygennady Member Posts: 677
    edited November 2013
    Pop safety valve

    Testing is done by insulating supply and return lines ( valves had to be installed by boiler installer). Then you have to jump pressuretroll and manual reset pressuretroll if it is installed. Then you turn thermostat all way up or jump it as well. Watch steam gage. Valve must pop open at 15 psi sharp. Also the best thing to do would be to hire professional for this testing. Do not do it yourself.
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
  • Pressure test

    What about putting both PRV's on a manifold, and then at least one will work hopefully.--NBC
  • Don't like what you see?

    What exactly is wrong with the near boiler piping? At least they aren't copper!
  • Small header

    Do you ever get any hammering in the header, with that reduced takeoff to the equalizer?

    If you look online at the manual for that boiler, you will see how it should have been piped, in order to produce good dry steam. How are your fuel bills?--NBC
  • handsonhandson Posts: 18
    edited November 2013
    Not as simple as I thought it might be!

    Thanks for the details. No wonder the plumber didn't want to test the PRV!
  • handsonhandson Posts: 18
    edited November 2013
    Not my boiler! :-)

    I forgot to mention that I'm not actually living with this heating system. It now belongs to my daughter and her husband. This is the first season they will be using it. The boiler has been out of commission for at least one year and maybe even longer. All of the copper pipes were stolen while the house was vacant. I'm trying to help them get things working rather than have the old boiler/piping ripped out to be replaced by a forced air system.
  • Hartford Loop?

    From a layman's pov it looks "close" (no pun intended)!

    The only thing that I can see that is questionable is the 3 inch header could have extended to a reducing elbow rather than a reducing Tee as it is currently piped. As I compared it to the Weil-McLain EG-55 installation for a counter flow steam system.

    Is this the issue?

    I'd like to know because I have arranged to have a professional review the system in December. He is the only contractor that I could find in Akron, Ohio...using the "Find a Contractor" button in the menu.
  • MDNLansingMDNLansing Member Posts: 297
    edited November 2013
    Not a Pro

    I'm only a homeowner, but from what I can see you are correct with the issue with your header. The header should have extended to the back of the boiler and reduced with an elbow down to the equalizer. Instead of reducing the main to the size of the equalizer in the horizontal plane, it should reduce in the vertical plane when the equalizer drops down. Like stated before, the Hartford loop should have a close nipple stead of the one currently installed.

    As for the pressure test, I wouldn't recommend charging your system to 15 psi. That's about 12 lbs above the maximum you ever want to run under any condition. Throwing 15 lbs through the entire system is asking for trouble. If it's new, you either assume it's good, or take it off and test it offline. Cap one side of it, connect the other side to a gauge and fill valve and then an air compressor. Open the valve and watch the gauge, it should obviously blow at or around 15 psi. So, something like this...

    Compressor - Nipple - Fill Valve - Nipple - Gauge - Nipple - Preassure Valve - Nipple - Cap.

    If you redo the near boiler piping you can install valves that isolate the boiler for future testing. That would allow you to only charge the boiler to 15 psi to test safety measures instead of charging the entire system. Depending on the age and configuration of the system, running it up to 15 psi could do a lot of harm.
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