I have high boiler pressure at 35 with no noticeable pressure venting, that’s probably a broke value and I don’t know how to reduce it.

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  • Welcome to the DIYSE you are going to need to supply more information for us to help you. A few pictures of the boiler system would be helpful. Also more details. Is there a pressure reducing valve? What type of cushion tank do you have installed? 35 psi is way too high and if it's a true reading it will imply multiple device failures. Reducing it is simple, just remove water. The CAUSE is the concern. – Joe Fala Feb 27 at 2:55
  • Does the PSI go up and down when the boiler warms and cools? PSI gauges can and do go bad. Joes suggestion about removing water will lower the PSI. – HazardousGlitch Feb 27 at 3:05
  • The boiler drain at the bottom of your circulator manifold can be used to drain some water to lower the PSI until the cause can be determined. Be sure to watch your pressure guage and make sure it's actually going down. What made you actually look at your pressure guage? – HazardousGlitch Feb 27 at 3:24
  • Thanks guys. That boiler heats everything in my house.. I haven’t spent a dime in 10 years on it, but it’s lookin over pressured and under performing these days.. story of my life. I just wanted to reduce the pressure before I have to call in the calvary. I really don’t know much about this stuff, but if it’s a easy solution im in. – Stu Feb 27 at 5:34

You will need to find out if the pressure in the boiler is actually 35psi or is the gauge out of calibration. That gauge is called a "tridicator" that measures the boiler's water temperature and pressures. That gauge may need to be replaced. If you haven't had the unit serviced in 10 years it is time to call someone to have that unit serviced. According to the tag on the boiler as shown in upper picture left side, your boiler is rated at 30 psi and the relief valve, the bronze looking thing with the red tag in the bottom picture should have dumped all the water needed to drop the pressure to just below that 30 psi. If that relief valve is bad and frozen that could create a hazardous condition and should be replaced immediately. A good service company will service, clean, and test all the operating and safety controls and return the boiler to a safe operating condition. You are not saving money with a dangerous and inefficient boiler. my 2 cents


This boiler is not serviced well. Go to hardware store and buy guage with female hose attachment. Screw on drain and open valve. It will tell you how much to drain pressure.


Bad pressure gauge, replaced and system working good thanks guys.

  • Hello, again. Thanks for posting your answer; would you mind fleshing it out a bit, perhaps with a picture of the bad pressure gauge, so that future visitors can benefit? Thanks. – Daniel Griscom Mar 9 at 18:21

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