Bryant gas boiler will not fire

Reply

  #1  
Old 11-23-08, 07:17 AM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Bryant gas boiler will not fire

I have an older Bryant gas boiler, model 234-4PW Series D fed by natural gas that will not fire. It is set up as a 3 zone forced hot water system. All three t-stats are calling for heat, & all three circulator pumps are working. The pilot flame is on, steady and blue in color but the furnace wont fire up. Just before this happened, the burner would fire for 5 or 10 seconds go off, then fire for another 5 or 10 seconds go off and continue until it was a steady flame. Recently it went through the cycling and then stopped without firing up. Since then the pilot remains steady and blue, the circulating pumps are running but no burner flame. Could it be a thermo-coupling or a pilot generator? Is that something I could fix myself?
 
Sponsored Links
  #2  
Old 11-23-08, 01:27 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
Bryant Boiler

It sounds to me like you are either not getting power to the gas valve or it is not responding. What is the number on the aquastat?
I could not find anything on your boiler on Bryant's web site.
 
  #3  
Old 11-23-08, 01:44 PM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
I'm really a rookie when it comes to gas boilers. I'm not sure what an aquastat is. Power seems to be OK. I was without heat all last night. Suddenly this afternoon the burner fired up and we began getting heat again. That lasted for a couple of hours and then it began short cycling again. The water level seems fine, and the expansion tank has a small amount of water in it. The water pressure is running around 12 psi. I don't hear any surging or gurgling noises when the water is circulating. Would there be a flame sensor that would be the culprit? I'm really at a loss and any and all help is greatly appreciated.
 
  #4  
Old 11-23-08, 01:52 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
Aquastat

Follow the wires from the gas valve. They should take you back to the aquastat. It is usually a grey box roughly 4x6". One of the most common aquastats is the Honeywell L8148. The letter at the end of the L8148 is important. Do you have a volt meter & know how to use it?
 
  #5  
Old 11-23-08, 02:51 PM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Yes, I do have a volt meter and know how to use it. Can you tell me how to upload a photo. I have some of the boiler that might help. One wire from the gas valve goes directly into the boiler Then a wire returns out and heads toward the pilot flame. Lastly a wire returns from the pilot flame area and back into the gas valve.
 
  #6  
Old 11-23-08, 06:15 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
Photo

The easiest way to post a photo is to open a free account with photobucket.com or similar photo hosting site, post the pictures there, & provide a link to them here.
 
  #7  
Old 11-24-08, 06:33 AM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Hope these photos will help If you can't see them on this post, they can be found on http://s421.photobucket.com/albums/pp294/Ja0r/
 
  #8  
Old 11-24-08, 06:11 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
Good Photos

Thanks for the pics but I'm afraid the controls on that boiler are not familiar to me. If I were there I could likely figure it out but not being able to put my hands on it...
 
  #9  
Old 11-25-08, 01:04 PM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
OK Thanks for your effort. Perhaps there is someone else out there that could help. I need to take care of this before the winter really settles in up here in the Northeast.
 
  #10  
Old 12-22-08, 07:11 PM
Member
Join Date: Dec 2008
Posts: 1
Received 0 Votes on 0 Posts
the high-limit control may be the problem

I have Bryant gas boilder 230-4WG, very old model. I found during very cold days the gas went off before the room temperature reached the set temperature. After I investigated every part of the system, I found the high-limit control was cut off by the heat from the furnace. The high-limit control is a device the prevent the furnace internal temperature goes too high, it is a safety control. I can not find the solution to this problem, either, because I can not find the same replacement part.
 
  #11  
Old 12-23-08, 02:52 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
High Limit

Are there any numbers on the control? A picture of it might help.
 
  #12  
Old 12-23-08, 04:55 PM
Member
Join Date: Aug 2006
Location: Baltimore
Posts: 37
Received 0 Votes on 0 Posts
Did you try replacing the thermo couple? My neighbor had a similar problem and that took care of it........
 
  #13  
Old 01-01-09, 10:05 AM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Grady, I've posted some photos that I hope will help. One in particular indicates the voltage readings I get as the burner kicks on and off. On the upper contacts that you see, the gas valve opens and the burner fires up as the voltage drops to 36.1 V. Then after +/- 10 seconds, as the voltage returns to 39.6, the gas valve closes and the burner shuts down. Out of the 4 contacts all readings were similar except for the one shown with the burner off at 19.9 and on when it drops to 17.8. Interesting that the short cycling problem seems to occur only when it gets down into the single digit outdoor temperatures (F). (johnz002's reply in this thread seems to hit on it as well.) The problem I seem to be having is the gas valve will not stay open long enough for the water to reach the high limit temp (Set at 190 F) In any case if you can look at the photo at the following web address I would certainly appreciate any help you can give: http://s421.photobucket.com/albums/pp294/Ja0r/ We are presently in a cold snap up here in the Northeast and the house temp dropped to 46 F last night. (Double clicking on the photo will increase it's size to make it more legible.)
 

Last edited by J0rlando; 01-01-09 at 10:09 AM. Reason: Additional info
  #14  
Old 01-01-09, 03:29 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
Voltage

On what is your meter set to be getting voltages like that? It should be on ac volts. Maybe set to DC?
 
  #15  
Old 01-01-09, 03:45 PM
Skip4661's Avatar
Member
Join Date: Dec 2008
Location: West Michigan
Posts: 298
Received 0 Votes on 0 Posts
Do you have two wires going to the pilot assembly, one wire being orange and rubbery and the other wire smaller and probably white in color?
 
  #16  
Old 01-01-09, 03:50 PM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
My meter is set to read 200V AC. The only settings in the AC range is 750V, 200V, 20V, & 200mV. If I set it on 20V, I get 1.0 or 0. When it is set to the 200V, I get the readings shown on the photo. There's a 24 volt transformer at the bottom of the controls, so I was surprised when I saw readings above the 24V. However, I really don't know that much about boilers so I had no idea if this was normal or not. Also, could you identify the parts shown in the photo? I believe the top section is the aquastat, the bottom a transformer, but I don't have a clue as to the middle part.
 
  #17  
Old 01-01-09, 04:01 PM
Skip4661's Avatar
Member
Join Date: Dec 2008
Location: West Michigan
Posts: 298
Received 0 Votes on 0 Posts
Looks like you have a two wire, Carrier type pilot assembly. The way this pilot operates, the pilot lights and heats up a metal strip. When this strip heats and flexes it closes a switch in the assembly. When this switch closes it sends power to open the gas valve. That pilot flame looks very weak. Probably not producing enough heat to close the switch. That pilot will need to be cleaned.
 
  #18  
Old 01-01-09, 04:26 PM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
There is one white wire and one yellow wire coming off the pilot assembly. they then connect to a twin black wire where one of the black wires connects to the gas valve and the other goes up toward the controls
 
  #19  
Old 01-01-09, 04:32 PM
Member
Thread Starter
Join Date: Nov 2008
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Isn't that just simply to keep the pilot lit?
 
  #20  
Old 01-01-09, 06:57 PM
Skip4661's Avatar
Member
Join Date: Dec 2008
Location: West Michigan
Posts: 298
Received 0 Votes on 0 Posts
Originally Posted by J0rlando View Post
There is one white wire and one yellow wire coming off the pilot assembly. they then connect to a twin black wire where one of the black wires connects to the gas valve and the other goes up toward the controls
If you can, check for 24v power on the wire coming from the controls and going to the pilot.. Then check for 24 volts at the gas valve on the wire that comes from the pilot. You should check these to ground or commom. If you have power to the pilot but not to the valve, the pilot switch is not closing. Regardless the pilot needs to be cleaned. Sometimes you can remove the aluminum tubing from the gas valve and blow through it. Sometimes this will clear the pilot orfice enough to be effective. Be sure to turn the power off before doing any work on the boiler.
 
  #21  
Old 01-02-09, 04:17 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 13,928
Received 0 Votes on 0 Posts
Control Parts

The top is the aquastat, middle is a relay (burner?), & the bottom is the transformer.
 
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: