Normal operating pressure for Burnham gas boiler

Reply

  #1  
Old 11-14-14, 06:02 AM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Normal operating pressure for Burnham gas boiler

Hi all,

I'm a new homeowner, so trying to make sure I'm doing everything right with the boiler. I have a Burnham P205W gas boiler for the baseboard radiators in a 2 story house. The water pressure was initially around 5 psi - not sure if the previous owner drained the system in the summer. I filled the water pressure to about 12/13 psi when the boiler was cold. After turning on the heat, the water pressure increased to about 20 psi and stayed there during the 3 hours of heating. The water temperature increased to about 160-180 degrees.

1. Is 20 psi a normal operating pressure for residential boilers? I see that the max allowable working pressure on the boiler is 30 psi. I've seen online that 12-15 psi is the normal pressure, but is that for cold boilers? Expansion leads to the 20 psi - just want to make sure that's normal. I check the boiler the next morning after turning it off the night before and the pressure went back down to 12/13 psi.

2. While the boiler was on and an hour after I turned it off, I heard some sounds from the pipes. Not loud banging from hammering, but maybe sounds due to the pipes expanding during heating and contracting during cooling. Is this normal?

Thanks in advance.
 
Sponsored Links
  #2  
Old 11-14-14, 06:31 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,473
Received 19 Votes on 16 Posts
Yes, all that sounds pretty normal. If you post a couple of dozen pictures of the installation there are a lot of highly talented people that can point out things to watch.
 
  #3  
Old 11-14-14, 08:58 AM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
I'll take a few pictures when I get home. Is it normal to drain the system during the summer? I was told to keep the pilot light on the entire year because we have a high humidity in the basement and the pilot light would help keep the parts of the boiler dry. I run a dehumidifier too. Would draining the system in the summer and refilling in the winter have negative effects on the boiler?
 
  #4  
Old 11-14-14, 09:34 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,473
Received 19 Votes on 16 Posts
Absolutely do NOT drain the system during the summer. The most corrosive thing in the boiler water is oxygen and that is driven off by normal operation. Draining and refilling accomplishes nothing but to bring in more oxygen so draining and refilling is MORE detrimental to the system than just leaving it alone.

Two different schools of thought on leaving the pilot burning. One side thinks a burning pilot will decrease the amount of rusting in the combustion chamber and gas passages, especially if the surrounding area is one of a high relative humidity. I think that a burning pilot RAISES the relative humidity in the combustion chamber because for every molecule of gas you burn you create two molecules of water vapor.

Leaving the pilot burning will cost you maybe two to five dollars a month with little gain (if any) in boiler longevity. Stopping the flow of air through the boiler (disconnect the chimney from the boiler) will be of greater use than anything in my opinion.
 
  #5  
Old 11-14-14, 10:05 AM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
That makes sense. I'll keep the system filled after this winter and will turn off the boiler and disconnect the chimney as well. Good things to know for my first time with this system!
 
  #6  
Old 11-14-14, 04:04 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Alright, here are some photos of the system. I turned on the system again today. The boiler came on until the water temp reached 180 and then went off. Stayed off until temp dropped to 165 and came on again. I understand the way the radiators work and the fact that the water temp drops as the air is heated around the radiators. I guess it's a long process of heating the house. We had a guy from the gas company come out a few months ago to check out the equipment for leaks and he "tested" the boiler by starting it up full blast directly at the boiler controller. The house became warm really quickly, much quicker than the way it's heating now. I guess that's because it was full blast before and now it's working at the normal temperature?

Name:  photo 1.jpg
Views: 3033
Size:  41.6 KBName:  photo 2.jpg
Views: 2633
Size:  37.3 KB
 
  #7  
Old 11-14-14, 04:05 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
I think it's a bit extreme to disconnect the chimney.
 
  #8  
Old 11-14-14, 04:06 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
The house became warm really quickly, much quicker than the way it's heating now. I guess that's because it was full blast before and now it's working at the normal temperature?
More likely because it wasn't cold outside.
 
  #9  
Old 11-14-14, 04:14 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
the water pressure increased to about 20 psi and stayed there during the 3 hours of heating.
20 PSI is not at all unusual, but it would be good to know that you've got the correct air charge on your expansion tank. I believe I see it peeking out from behind the ductwork at the ceiling.

Read this:

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

There are step by step instructions to be followed TO THE LETTER in order to assure proper air charge in that tank.

Technically, it shouldn't be installed on it's side either. It's done all the time though by installers that can't read instructions or think they know better, or that it doesn't matter. Yeah, it works... but it isn't technically correct.
 
  #10  
Old 11-14-14, 04:16 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
sounds due to the pipes expanding during heating and contracting during cooling. Is this normal?
Most likely expansion noises... pinging, clicking, and an occasional 'thump' are normal. LOUD bangs that wake NJ Trooper from a drunken stupor are NOT normal though... still, probably expansion noises, but not normal.
 
  #11  
Old 11-14-14, 04:17 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
the baseboard radiators
Copper tubing with aluminum fins? or cast iron?
 
  #12  
Old 11-14-14, 04:29 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Copper tubing with aluminum fins. Looks like cast iron covers for the fins. Look a bit like the one on the left, just colored: http://www.oldcastironradiators.com/...Baseboards.htm
 
  #13  
Old 11-14-14, 04:35 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
So is it just a matter of waiting for the radiators to heat enough and heat the rest of the house. Seems like a long process, at least based on the thermostat.
 
  #14  
Old 11-14-14, 05:32 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
Copper tubing with aluminum fins. Looks like cast iron covers for the fins.
You can look down in the vents and see the copper and fins?

Can you post a picture or two of them?

If they are copper fin tube and someone has replaced the covers with some other design, it's possible that if the covers do not fit properly the heat output will be REDUCED. The largest part of fin tube baseboard's heat is from air convection through the unit. If the fin tubes are not flush with the front and rear covers, air will be diverted AROUND the fins, rather than THROUGH the fins and the heat output will be reduced.

That said, perhaps the covers do fit properly... and in this case I would ask if you've had the covers off and thoroughly brushed and vacuumed the fins. You would be surprised at how much even a thin layer of dust accumulated on the BOTTOM of the fins can reduce the heat output. This will cause the burner to run longer in order to heat the home.

Also, the bottom vent needs to be clear in order for enough air to move through them. If there's wall to wall carpeting blocking the bottom vent for example, that too will greatly reduce the heat output.

So is it just a matter of waiting for the radiators to heat enough and heat the rest of the house
Well, yeah, sorta... I mean that's what heating is all about... but if the radiators aren't putting out the heat they should be, the time will be longer...
 
  #15  
Old 11-14-14, 06:24 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Sorry, my mistake. They're just cast iron. I guess it's not a cover, but the actual radiator: Baseray Baseboard Radiator | Cast Iron Radiators | U.S. Boiler Company. I see some dust in places. Will vacuum tomorrow and see how much I can get. Can't really take these off the wall, so hard to get access to the inside of the radiator.
 
  #16  
Old 11-16-14, 09:20 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
Probably not going to make THAT much difference unless they're really full of dust... it will help some though, just not as dramatic as fin tube.
 
  #17  
Old 11-16-14, 01:20 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Heating seems to be working better. I'm been patient letting it heat the house and it holds the heat well. Noticed something new today. If you look at the photos I posted below, the copper pipe right behind the yellow gas input has a faucet/drain on the bottom. Even though it's turned all the way in the closed position, I saw a few drops of water on the ground below it today. Is the system adjusting for a high pressure - it was around 21 psi last night. Is it just a safety in case the pressure gets too high? Thanks.
 
  #18  
Old 11-16-14, 02:05 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,473
Received 19 Votes on 16 Posts
I can't see the faucet/drain (didn't look real hard) but it is NOT "adjusting for a higher pressure". There should be no leakage at that drain. Easiest thing to do now is to buy a garden hose cap with a regular garden hose gasket (washer) and screw it onto the drain.

[ATTACH=CONFIG]41786[/ATTACH] (Image courtesy of amazon.com)
 
Attached Images  
  #19  
Old 11-16-14, 07:12 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Here are some closer photos. The valve I'm talking about is on the right. I don't mind putting the cap on, just don't want to cover up something which should remain open. What exactly is the valve for? Name:  boiler 3.jpg
Views: 2473
Size:  43.0 KBName:  boiler 4.jpg
Views: 2167
Size:  35.9 KB
 
  #20  
Old 11-16-14, 07:58 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,473
Received 19 Votes on 16 Posts
Mostly for draining the system. Might be used under special circumstances to "power purge" the heating loops. Adding the cap is a proper thing to do, especially during the heating season.
 
  #21  
Old 11-17-14, 05:51 PM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Thanks Furd. Maybe I'm just being paranoid since it's my first time with the system. I know the quiet tapping sounds in the walls are likely from the expansion/contraction during heating. I only really hear it when the boiler runs and the first 15 minutes after the boiler shuts off. Pressure seems to be steady, not dropping. Here's the paranoid part - any chance the tapping is actually a leak in the pipes and it only happens when pressure goes up during heating? It's a fairly constant sound that starts and stops off an on. Don't have access to see the actual pipes since they're in the walls. Tried to look in the basement, but can't see anything suspicious. If I had a leak, would I see a pressure drop pretty quickly? Thanks again!
 
  #22  
Old 11-25-14, 12:09 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,473
Received 19 Votes on 16 Posts
Sorry to be so late in responding, I spent most of last week in the hospital.

Turn off the city water make-up feed to the system and watch the pressure. If it holds stead, allowing for the changes due to temperature, you have no leak.
 
  #23  
Old 12-02-14, 06:26 AM
Member
Thread Starter
Join Date: Aug 2014
Location: USA
Posts: 84
Upvotes: 0
Received 0 Votes on 0 Posts
Thanks Furd. Hope all is okay and hospital wasn't anything serious.
 
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: