High pressure in my Weil-McLain boiler system

Closed Thread

  #1  
Old 08-08-18, 05:27 PM
Member
Thread Starter
Join Date: Nov 2012
Location: USA
Posts: 71
High pressure in my Weil-McLain boiler system

I noticed water on the floor around the boiler the pressure relief valve was discharging each time the boiler kicked on to heat our water. The pressure has almost always been over 30 and 40 according to my boiler gauge. I have changed both of the expansion tanks in my system over the last two days. The expansion tank on the boiler was not holding a charge. The other expansion tank was on the water holding tank and it would leak water out of the air valve when checking PSI. I followed the PSI gauge instructions link on this site to check my own boilers gauge and it is showing that the pressure is higher then the gauge is reading on the boiler by 20 psi which is the water pressure in the house 60 psi.

Not sure what to do next to trouble shoot. This? I thought I bled the system correctly but maybe I did not or maybe I am missing something. I had a similar problem 4 years ago and NJ helped me out.

Any help greatly appreciated

Thanks

oak
 
Attached Images       

Last edited by Oakey; 08-08-18 at 05:49 PM.
Sponsored Links
  #2  
Old 08-08-18, 06:34 PM
Member
Join Date: Mar 2010
Location: USA
Posts: 3,048
Preset the boiler expansion tank to the intended boiler cool pressure (probably 15 PSI) before installing it or with the heating system pressure near zero (let water out to achieve this).

Preset the expansion tank above hot water tank to a few PSI less than the intended domestic water system pressure (after any pressure regulator). For a pump and well system set this expansion tank to a few PSI less than the normal minimum water system pressure aka pump turn on pressure. Do this with the main cold water shutoff closed (or pump shut off) and a cold faucet open upstairs resulting in near zero system pressure at that moment.
 
  #3  
Old 08-08-18, 09:24 PM
Member
Thread Starter
Join Date: Nov 2012
Location: USA
Posts: 71
I pressurized the Hot Water Expansion tank to 2 - 3 psi less then domestic water pressure as you said. I could not get the boiler down to zero but I did get it close maybe 5 psi and checked the psi whi said 12 psi. The new tank came pressurized at 12 psi. I just started it up again it stayed at 20 psi when I came back down 40 minutes later it went up to 40 psi again?
 
  #4  
Old 08-09-18, 05:48 AM
Member
Join Date: Jan 2008
Location: Southeastern Pennsylvania
Posts: 2,652
I followed the PSI gauge instructions link on this site to check my own boilers gauge and it is showing that the pressure is higher then the gauge is reading on the boiler by 20 psi which is the water pressure in the house 60 psi.
Are you sure you had the test gauge connected to a boiler drain? It sounds like maybe the gauge was connected to a domestic water drain.

(but I'm not one of the experts)
 
Closed Thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes