Burnham Boiler Issue
Hoping someone would be willing to help out with my Burnham Low Pressure Boiler (see photo 1).
I seem to be having issues with the automatic pilot (theres no manual ignitor).
I have attached a few photos to help walk through the troubleshooting I did. When i turn power on i hear the thermostat click in and I believe the exhaust switch click? Then i hear the gas valve click and the thermocouple/ignitor click? I seem to be having 2 potential issues...
- The gas valve ignitor plug seems to be reading 63 volts. Shouldn't it be 24?
2. The lines to the high limit/roll out switch seems to be reading 0 volts...Once again, shouldn't it be 24?
I replaced the ignitor/thermocouple and it glows, so that appears to be working. I have the thermostats on and set way high.
is my gas valve shorting out and not properly opening to allow gas to flow? I dont smell gas. Photo just showing i have 24 volts at the transformer.
It just feels like im having a gas supply issue but I dont know why.
Comments
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Should be a wiring schematic inside the front cover, or in the manual. We need to see what else is in that circuit.
Is there a vent damper on the boiler? That is a common cause of no fire conditions.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream
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That is a Honeywell 'Smart Valve". They work a little different. That model valve is pretty old and is no longer made. The valve shown on the attached is a direct replacement so everything should be the same as far as troubleshooting.
Troubleshooting starts on page 11.
The hot surface ignitor is also the flame sensor. Since it is glowing it should be ok. First thing is check all wiring connections.
Then try the troubleshooting chart.
Come back her for more help
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Your second picture is where you are measuring voltage to the hot surface igniter which will be greater than 24 volts in order to get the igniter hot.
Your third picture where you are measuring voltage to the flame rollout switch, you are only measuring one leg of the transformer, so you won't see voltage unless your other lead is placed on the other leg.
Your problem could be as simple as a clog in the small aluminum pilot tube that goes from the gas valve to the pilot. A technician would unscrew the brass nut that connects the small aluminum tube to the control and see if gas comes out of that port on a call for heat. If yes, there's a clog in the line, probably at the pilot. If no, you may need a new gas valve.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 -
there are a lot of YouTube videos on how to troubleshoot a HW Smart valve, if that helps
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
that black zip cord looks like it goes to a safety outside the cabinet. is that going to a vent damper?
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Some of the Smart Valves only use 24 v to the HSI ignitor.
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The photo you sent shows the manual ball valve on the left is shut. Did you close that while you were testing? If not that would be your issue. If someone opened the gas line to the atmosphere there will also be air in the lines that you can bleed from the union. Tighten the union once you smell gas and it should fire up.
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Thanks for the responses everyone. I didnt realize I had any comments. Attached are 2 more photos; one of the schematic and one of the damper. I have pressed the reset switch on the damper and it didnt lead to ignition. is there anything else I can do to deal with a potential damper issue?
to the poster who asked about the gas valve being off, unfortunately I turned that off after attempting to fix it. I wish it were that simple!
Also, on the ignitor gas line, do you all prefer tape or pipe dope for sealing it?
Thanks, I really appreciate it!
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Thank you, how would I troubleshoot the damper? I assume you mean the switch may be bad?
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There is a vent damper. See photo above. There is a reset and I pressed that. Is there a correct way to use a multimeter to check its function? I feel like I hear 2 clicks when I turn on power. the thermostat and vent. Is that what I should hear? Should I take a video?
To add some context, I changed a gate valve and everything was working last year. At some point I turned off the thermostat and it never called for heat again. I didnt completely shut off the boiler. Now, 8 months layer, I cant get a pilot.
I did notice the burners and bottom were very dirty. I cleaned the burners with a wire brush and vacuumed out the bottom.
Thanks!
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If the vent damper were not opening, or if a safety were open, it would not allow the pilot to ignite. Once the pilot is lit, the only thing preventing the Smart valve from opening is that it must sense that the pilot is established. If the pilot is good, then the Smart valve is the problem. This is quite common with them.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
I feel like I hear the damper click. What is the best way to see if the damper is open?
I also used pipedope on the gas line for the ignitor. I am going to clean it off and use tape. I was thinking that maybe it is blocking the gas and preventing ignition.
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Again, if the pilot is staying lit, the problem is the Smat valve, not the damper.
You should not have used any dope at all on the pilot line: it’s a compression fitting, not pipe threads. But if the pilot is staying lit, leave it alone.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
Interesting, I will clean off the pipe dope and retighten. To be clear, I dont have a lit pilot light, I just have a lit surface ignitor.
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The position of the shaft tells when the damper is open. Ten a switch in the damper when fully open allows power to the gas valve.
In this pic the vent is full open. when the call for heat stops this flat metal shaft should turn 90°. Does it?
In some cases those dampers can be manually forced open, maybe a black switch on it to allow that?
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
If the ignitor glows, then its making through all of your safeties. Issue seems to be with either the smart valve itself or gas supply.
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Thanks Bob! I will check if it closes when I get home. I would think that if the vent is fully open, it would not prevent the smart valve from opening, correct? So that seems to suggest i either have a blocked line or failed smart valve?
If I could ask another question…is this boiler getting to the point I should just replace it? Is it worth fixing a 29 year old boiler?
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