Ignition problem
Comments
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that is the atmospheric vent for the regulator. in some circumstances it may need to be piped outside but it is not a pressure tap. some gas valves have a pressure tap bult in to them too. otherwise you might need to adapt off the drip tee.
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Ok. I'll shut the gas and put an adapter on the drip t, don't see any other ports. Thanks
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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Inlet pressure (mbar), while off. Do we need a reading while it's running as well?
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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yes. the idea is to see if it drops below about 4" wc when everything goes out.
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No. that's the gas valve vent.
When the main burners ignites is it blowing out the pilot? Was the pilot assembly put back in the correct position?
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In my video you can see the pilot is on along with the burners. Then the pilot goes out followed by the burners, also seen in video. (The pilot stays on a minute before going out)
The pilot assembly bolts into place. No way to reposition it without modfying the brackets.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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Ok. I'll have to go back and measure that drop.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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When i saw the video the burners were already lit and pilot was dying. I don't think i saw the beginning
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Yes, i trimmed a minute off the start to show the moment the pilot dies followed by the burners...i.e. the minute i cut was identical to the few seconds at the start of the video.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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Inlet pressure goes down just a little to 16.9 when the burners come on. Will try again tomorrow with a new thermocouple. Her pilot assembly has a tab broken off, has been working years with it like that so I doubt it's the issue. Will look for someone local who can do a combustion analysis if tomorrow is a fail.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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what is the pressure when it goes out? the pressure should drop a little when there is flow.
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i didn't have the ability to watch the video until now. what is happening is
- the pilot burner goes out.
- the thermocouple cools because the pilot burner is out
- the safety valve closes ant turns off the main and pilot burners because the thermocouple isn't being heated by the pilot burner.
the root cause is the pilot burner going out.
ideally you'd have fittings to tee in to the pilot burner line and check pressure there and see if it still has pressure when the pilot goes out.
disassemble the pilot and tubing and make sure there is no debris in the tube or in the orifice in the burner assembly.
look for someone that knows how to adjust oil burners and gas power burners if you can't specifically find someone that understands conversion burners. can also look for people nci certified in combustion.
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Pilot looks good while it is burning. kind of strange to have the pilot cut out like that. The thermocouple works or it wouldn't pull in.
I would think a defective valve (maybe they ran over that as well) or incoming gas pressure issue.
I would eliminate a gas pressure issue and see what is left.
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they had some sort of issue with the old valve too so it is possible it is the new valve but unlikely.
if i'm following the pilot goes out after a minute to a few minutes with the main burner off too.
since it does it with the burner off i'm leaning toward some debris in the pilot tube that is getting blown in to the orifice as @109A_5 suggested as i think it out more
if you tee the monometer in to the pilot burner and it goes out while still having pressure with the burner off then it has to be some sort of clog/debris in the pilot burner.
is that a reverse flare for the pilot port? auto parts store is the place to get fittings for that
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looks like it is a weird reverse compression fitting, might have to do something with tight fitting tubing to test it. it is low pressure so you can use vinyl or rubber tubing slip fit over for testing
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I watched the video. That is odd. The pilot also sounds odd, like maybe the pilot gas pressure is too high.
" Ok, so the pilot goes out on it's own after a few minutes, thermostat off. "
I'm wondering if the pilot gas pressure is too high so the thermocouple is not being heating correctly. The pilot gas pressure is adjustable.
Not that is matters much now but the inlet pressure port (if it exists) is above the inlet gas pipe tapping.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
Thanks. What should the pressure be?
First, I'll remove the pilot tube and make sure it's clean (using compressed air) as Mattmia suggests. Then I'll reassemble using a new thermocouple.
Not sure about the reverse fitting flare, will check that too.
Thanks all
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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take the pilot burner apart, there is usually an orifice in there, make sure there isn't something floating around in there.
you set the pressure by the flame size. that flame is big by modern standards but is probably right for that old burner.
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When the pilot goes out you can here the agitated flame sound go away. Debris in the orifice or poor orifice shape, gas pressure too high to the pilot. Inspect the orifice. Not sure there is an actual pressure specification for the pilot gas circuit. As @mattmia2 suggests adjust by flame size. It just sounds wrong to me.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System1 -
Will check that orifice tomorrow morning
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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i would be careful about how i took it apart to try to catch any debris that is in the pilot burner tubing or burner. i'm thinking a piece of teflon tape or fiber or something like that is in there.
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9.2 mbar = 3.69 inches of water column. That's a bit high going to the burners.
16.9 mbar = 6.79 inches w.c. I'd call that marginal.
There's either a problem in the inside gas piping or a problem with the incoming gas service. Try to check the pressure at the meter. You may have to get the gas company involved.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting0 -
Thats looks like the internal regulator vent. you may need to remove the drip leg nipple and cap and measure inlet pressure from there. You mention "local plumbing" are you in the SF Bay? Also change the scale to inches of water column that's easier for most of to work with and reference at least….
oops i now see other replies.. lol i had my browser up for awhile before commenting..
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Ok. Took apart the pilot assembly about three hours ago. One of the two tiny orifices looked possibly blocked. The wire i could find was either too small(soft) or too big to poke through so hit it from both ends with compressed air.
Put it back together with a new thermocouple, and fired it up. Has been on since. If it lasts through the night I'll call it a win.
Thanks again.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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Sounds good.
The smallest wire of a typical Oxy-acetylene tip cleaner may help if needed. There are other ways.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
in my area 7 at the regulator and 6.5 out of the meter is pretty common.
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it is better to use something soft unless yo know what you're doing, it is pretty easy to increase the size of the hole with steel tools and increase the firing rate.
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Well aware of that thanks. I build race motorcycles for fun, I love jetting/setting up carburetors. Jets have to be cleaned carefully for the same reason
Pretty funny you pictured those, as a welder the first thing i tried was the nozzle cleaner..smallest was too large. I have those tiny drill bits because sometimes drill out my own carburetor jets, nothing was small enough. I make my own motorcycle control cables so tried unraveling a strand of the smallest, still too big. Tried unraveling copper strands from electrical wire, the only one small enough was too soft to be of use.
I would have just bought a new pilot assembly but didn't find any locally.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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baso gas products makes all the parts for a pilot like that
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Yeah when you get down that small soft is pretty useless. Maybe a strand of bicycle shift inner cable, the diameter is smaller than the bicycle brake cable. So far I can't find any data in the strand diameter.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
Insanely small. Probably easier to just have a spare basso part on hand than finding the right sized orifice cleaner.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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The problem with replacement is getting the hood and the orifice size correct, many to choose from. Maybe you can reuse the hood. You may have to adjust the pilot adjustment on the gas valve to get a replacement to work correctly.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System1 -
I rip a piece of wire off of a copper cleaning brush. its thin and sturdy enough to clean the pilot holes. I hold the orifice up to a light bulb and look thru it to see if its clean. In my area R E michels carry batwing pilot assemblies. Or they used too
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I looked at my brass brushes but the strands were too short to reach the orifices.
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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Was wondering about that when looking at online replacements... aren't the sizes stamped on them?
Bryant 245-8, 430k btu, 2-pipe steam in a 1930s 6-unit 1-story apt building in the NM mountains. 26 radiators 3800sqf
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the orifice is a separate piece that goes inside though i have never taken one apart so i'm not 100% sure how. is it staying lit? i was thinking something like a strand of #30 or so stranded wire
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The Honeywell Q348U is a universal batwing replacement.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting1 -
I was working on a different project using a Stainless Steel wire brush. It is a small wire brush, not much bigger than a tooth brush. The wires measured 0.007 inches or 7 thousands of an inch, probably smaller than most pilot orifices for NG. The smallest wire in my torch tip cleaner was about 0.018 of an inch.
Not sure if the orifice size is stamped on the orifice like with automotive or motorcycle carburetor orifices may be.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System1 -
looking at the honywell catalog it looks like they are coded.
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The Q348U comes with several different orifices. For target-type pilots, check out the Q345U, which has an adjustable head as well as different orifices.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting1
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