What is safe output temp and pressure for boiler, home


  #1  
Old 10-11-12, 02:20 PM
G
Member
Thread Starter
Join Date: Oct 2012
Location: USA
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
What is safe output temp and pressure for boiler, home

Starting up boiler for first time. Output temp was 200f and raising, pressure was 45 psi and raising, got scared and shut it down. (pressure gauge has red arrow at 20 psi, is this the max or min pressure). thermostat was set to 75f, the room temp gauge was a little below 60f and shaking, room temp by stand alone themometer was 62-65. Do I have a problem. What is good output temp/pressure for WEIL-McLAIN CG-5-SPDN boiler in a two story home?
 
  #2  
Old 10-11-12, 04:05 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Sounds like a problem to me.

Your system should probably not go much above 180°F

The pressure should be around 12-15 PSI when the system is COLD, and may increase by 5-8 PSI when it is at 180°F

Please read:

http://www.doityourself.com/forum/bo...ure-gauge.html

http://www.doityourself.com/forum/bo...sion-tank.html

pressure was 45 psi and raising
This should NEVER happen. There is a SAFETY RELIEF VALVE that is set at 30 PSI which should ( MUST ) open and relieve pressure.

If you saw 45 PSI, then two things:

Either your SAFETY PRESSURE RELIEF VALVE is plugged and this is VERY dangerous!

OR, your pressure gauge is not accurate.

ALWAYS ERR ON THE SIDE OF CAUTION! Do NOT assume that the gauge is bad. If any assumptions are made, ALWAYS ASSUME that the relief valve is plugged in situations such as this, to be on the safe side.

If the relief valve is more than 5 years old, have it changed, plain and simple.

Verify your pressure and temperature gauge accuracy.
 

Last edited by NJT; 10-12-12 at 08:03 AM.
  #3  
Old 10-11-12, 04:07 PM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,344
Upvotes: 0
Received 1 Upvote on 1 Post
See the following: http://www.doityourself.com/forum/bo...ure-gauge.html

Your pressure gauge [MAY BE] wrong. If you had 45 psi in the boiler, the water would have spewing out of the pressure relief valve. You need to [VERIFY THE] gauge on that boiler to do anything else.

You are unlikely to need you water temp to be any higher than 180F. Pressure should be about 12 psi when cold. Take some good pictures of everything and post.
 

Last edited by NJT; 10-12-12 at 08:00 AM.
  #4  
Old 10-11-12, 04:58 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
Pressure at 45 psi...
Your pressure gauge MAY be wrong or your safety valve MAY be defective. Look for the nameplate on the boiler and see what the Maximum Allowable Working Pressure (MAWP) is stamped for, it could be as high as 60 psi although 30 psi is most common.

That stated, very few installations require any more than 20 psi maximum.
 
  #5  
Old 10-12-12, 05:48 AM
N
Member
Join Date: Jan 2012
Location: Canada
Posts: 2,511
Received 21 Upvotes on 18 Posts
Welcome to the forum.
I was you last december when we moved into our current home with our first boiler.

As the others have already mentioned, too hot and too much pressure. The red arrow on 20PSI is about where you should be when the boiler is hot.
If you (like myself) just purchased the house with the boiler and know nothing of it's history, replace both the relief valve and gauge and be done.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: