Nuisance lockouts and flame failures
webster Burner JB-1 constantly having random flame failures. manifold gas pressure is 2.6” its firing natural gas, pilot gas pressure was 3.45. I’ve tightened all electrical connections, check them every time I service the unit, it’ll randomly just drop out. I’m running for combustion: 8.0 o2 7.22 CO2 3ppm, consistently. 9.9 volts dc for flame signal(manager had to go back 10 days after and checked some more stuff.) it’ll run for a while then just lockout. You reset it, it picks up where it left off and runs again. What else would you recommend I check?
Update: Pilot assembly plan on checking it when I go back there. I checked the pilot gas pressure but as you all know it worked perfectly when I installed my manometer in the tap. I’ve been highly considering having them install a Honeywell 7800 just so we can see what’s going on and when? I know it’s expensive but they’ve spent quite a bit on having us out there constantly.
Comments
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Spark gap within spec? Electrode(s) in good shape, look real good at porcelain insulator for cracks. Ignition transformer provide a good sized spark?
Are you referring to pilot gas pressure or main gas pressure. You need to check both at test tees.
Does the flame light instantly, or is there a slight delay? In most cases with gas power burners (most burners I guess) the problems are normally with getting the pilot lit and established. Rarely does the flame drop out on main flame.
Webster burners used to be common here in NJ, however I have not touched one in years. We see more Powerflame burners, the smaller ones (about your burner size) are prone to inadequate air for proper light off and a stable flame during pilot. If all else fails and your pilot gas pressure is good, might want to open the air shutter slightly and see if things improve.
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I danced with a similar problem on a similar power burner.
It might be the pilot gas regulator falling down when the main valve opens.
Or the pilot lifts off it's burner (and away from the flame sensor) when main valve opens.
Another case was the pilot gas was tapped after the main gas valve regulator and this confused the pilot regulator when the main valve opened, dropping the pressure to the pilot regulator. Took me years to finally notice that simple gas train problem…..but it was installed by an old pro, so you are not to question the "dead men"…..assume they did things right on the original install.
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I agree that definitely sounds, plausible kind of where I’m looking to be honest. They have a fire-eye safeguard so it doesn’t tell you anything it’s the model D I’m pretty sure. They’re getting a bit aggravated with us so I’m hoping to get it fixed pretty soon.
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You need to check your gas pressure. you seem to be a little low on your CO2 which obviously means a little high with your O2. check it against the spec.
is this a high fire measurement? if it is I would be surprised it when it goes to low fire is when you lose it your O2 should get even higher in low fire.
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I worked on quite a few Websters back in the day. What kind of flame sensor does it have? I am going to assume UV. I hate flame rods and find them unreliable, so I hope its not that.
One thing I have run into a few time that some do not realize is low line voltage for the control circuit.
Most ignition transformer are rated @ 120 volt primary. If your only getting110 or 115 volts this will affect the ignition transformer output for instance a 120-6000 volt tans running at 110 volt input will only put out 5460 volts.
One way or the other with commercial burners it is usually the pilot, weather a gas problem, or an ignition problem. Flame sensing is another common issue. Especially if you have a hated flame rod.
Is this happening just in the recent cold weather? Or has it been a problem all along?
I had problems with 3 jobs in a particular city during cold weather all three burners started locking out. They were all different PowerFlame burners.
I found out the gas company was dumping propane into the natural gas supply to help keep the pressure up during heavy demand (called shaving). The fix on all three jobs was to take off the factory supplied 120/6000 volt transformers and install 120/8500 volt transformers which I don't think are available now. Webster transformers.
Believe it or not.
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If you have 2.6" at high fire, that is good but you might need to put an analyzer on it and keep an eyeball on the flame ( or on meter measureing uv voltage.). It could have a spot in the curve that is lean and goes "invisible" to the UV sensor or as others have said, the flame lifts off the pot and out of sight. Does this burner modulate to low fire and stay lit? Or, does it turn off until called upon and relights? I ask because you were going to check the pilot. I would think you have an intermittent pilot that extinguishes once main flame is proven.
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it’s UV with a fire-eye flame safeguard it only happens in the winter and usually on mondays it’s very weird. I’ll definitely check that.
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it has the capability for high and low but I think it just fires on high fire. It seems to me like the pilot stays lit even when main flame is open. I could be wrong though. That does help me a bit with more to check.
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What is the combustion air temperature?
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it is an outside shed I do not know, it may be a bit cold.
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With that size burner yes they often did leave the pilot on.
Winter and being outdoors is a clue for me
Never had much trouble with Webster pilots. Power Flame is more of a problem. If you check the gas pressure and everything checks out You might go for a larger ignition trans.
But you mentioned high and lo fire and it always runs on high. Is the air damper in the low fire position when the burner lights? Where is the scanner mounted I forgot inside the blast tube I think??
Normally you want the air damper open about 1/4-3/8" for ignition
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Flame scanner is in the blast tube, the damper really doesn’t move much. Yes the damper is always in the same spot, It has a linkage tied to a gas valve.(double block) I’ll check the damper also make sure, it’s weird setup to me I was told it can do both low and high I’ve only ever seen it do high fire.
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If you look inside the gas valve actuator if there are only 2 wire the valve just goes open and closed….no lo-hi fire.
If there are 4 wires inside 2 are 120v to power the valve from the Fireye gas valve terminal. The other 2 wires are lo-high fire. They would usually go to an aqustat or pressure control depending on if you have steam or water. That control would do the low hi fire.
When the valve opens if the LO_HI fire control is "made" the burner goes straight to high fire. When that control opens it goes back to lo fire.
One problem you can have with that set up I have seen a couple of times is when the gas valve gets powered and starts to open it immediately starts to open the damper even though the gas has not gone through the valve yet and the burner has not lit. This increased air may give you pilot issues if that is happening. You can usually get around it by adjusting the air damper or linkage
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appreciate the information thanks
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