What should the pressure be on a Buderus boiler when heating up

Reply

  #1  
Old 01-08-11, 05:22 PM
Member
Thread Starter
Join Date: Jan 2011
Location: US
Posts: 2
Upvotes: 0
Received 0 Votes on 0 Posts
What should the pressure be on a Buderus boiler when heating up

A couple of weeks ago I woke to my wife telling me the boiler was leaking, it turns out the relief valve was leaking. So I shut down the system, replaced the relief valve, and started it back up. Seemed alright for a few days and the I noticed a little stream of water running across the basement floor, thought maybe I bought a defective valve so I relaced it again. Still the same thing. I checked the pressure gauge today and it was at approx. 39 psi at 170 degrees, how can you tell if the expansion tank is bad?
 
Sponsored Links
  #2  
Old 01-08-11, 05:36 PM
Member
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,340
Upvotes: 0
Received 0 Votes on 0 Posts
Originally Posted by setzenfand View Post
how can you tell if the expansion tank is bad?
The expansion tank may not be "bad," just waterlogged. But first, what type of exp tank do you have? Bladder type or conventional steel? Don't replace any more components until you have the problem troubleshot. You've now wasted money on three relief valves. Need to apply logic before throwing parts at it - or call somebody to help.

What does the boiler temp/pressure gauge indicate?

Photos of your system would help us. http://forum.doityourself.com/electr...your-post.html
 
  #3  
Old 01-08-11, 07:45 PM
Member
Thread Starter
Join Date: Jan 2011
Location: US
Posts: 2
Upvotes: 0
Received 0 Votes on 0 Posts
Im not sure but it looks lie a propane tank for a grill. The pressure was around 39 psi at 170 degrees and then the relief valve would startto leak.
 
  #4  
Old 01-09-11, 05:18 AM
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Upvotes: 0
Received 0 Votes on 0 Posts
You have a bladder type expansion tank. Turn off you system and let it cool down to 100 degrees or less. Then drain water out of the system until the pressure is 0 psi. Check the pressure on your expansion tank with a standard tire pressure gauge. It should be 12 psi. If any water comes out when you do this, then the bladder in your tank has failed and you need to replace it. If the bladder appears to be ok, then raise the pressure of the tank to 12 psi. After you get your expansion tank sorted out, refill the water into your system until the pressure gauge on the boiler reads 12 psi. That is the minimum pressure you should have when the boiler is cool. If you have more than 3 floors in your home, it will need to be higher. When the boiler is hot, the pressure will rise a few psi.
 
Reply

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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: