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  1. #1

    Gas Valve doesn't open fast enough

    Payne furnace 6 years old ran flawlessly until a week ago. Locks out due to no flame present. Random ignition as follows. When valve opens and first burner only lights, next four will light in time for flame sensor to register flame present, even though there is a noticeable delay in ignition. This happens maybe one out of 6 or 7 attempts. When first two burners ignite (almost simultaneously) last three burners will not ignite and furnace shuts down due to no flame present. This is most common scenario.
    Outlet gas pressure starts at 2.5" and slowly raises to 3.5 after approximately 4 seconds ( have to manually light burners to take this reading). Inlet gas pressure was 6" static and dropped to 5" after valve opens and lights. Replaced gas valve and problem still exists. Gas company changed meter and regulator and now inlet is 7" and drops very little when manually lighting furnace, but problem still present. Going a little nuts now, so I recheck everything including manifold alignment and all looks good. I just can't get the slow opening OEM valve to open fast enough to light all the burners before lockout. Any ideas?

  2. #2
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    I'm sure you checked, but are the crossovers dirty/rusty?

  3. #3
    Yes, I checked. Forgot to mention that in my original "long" post. Slid one piece burner assembly out and checked it. Actually, entire furnace looks brand new. Crossovers clean and evenly spaced (no crimping). Thanks though.

  4. #4
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    Sounds like you have it covered.

    I would try a universal fast opening valve to see if that was the problem.

  5. #5
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    And welcome to the site.

    We have a ton of good stuff on the pro section, after 15 posts you can apply for pro access.

  6. #6
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    Have you tried actually wire brushing and/or blowing out the crossovers to clean them?

    I've had really tiny bits of lint/dust, and flakes of galvanized coating play hell with burner ignition before.
    If more government is the answer, then it's a really stupid question.

  7. #7
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    any spiders in the manifold? orifices are clean? is this a 80% or 90%?

    could be combustion or venting problem. try opening both sides of intake and cycle furnace 10 times.

  8. #8
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    look at the burners someone may have pulled them out before you they only go one way. look at the pinched ends on the runner bar just a though seen it before.

  9. #9
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    Quote Originally Posted by chuckcrj View Post
    Sounds like you have it covered.

    I would try a universal fast opening valve to see if that was the problem.
    That could be opening up a law suit if you are considering that as a permanent fix. The last thing you want to do is is give the manufacturer that kind of ammo. "hey man it didn't ship that way'

    I agree with your idea in theory as I have seen slow open valves do all sorts of crazy things. I imagine that a slow open valve by it's very nature is going to compound any ignition problems.

    A spider in an orifice should cause the same problem on each ignition. I am guessing there is no air adjustment capability.

    Is this happening with the blower off or on?

  10. #10
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    is the outlet pressure on the new valve still 2.5-3.5?? that 7" is kinda teetering on the low side of usefulness. check the valve specs for minimum input ratings.

    Has the gas company done any work in the area that may have lowered main line pressures??

    second the efficiency question too.....80%, 90%??

  11. #11
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    Quote Originally Posted by Glennhvac View Post
    That could be opening up a law suit if you are considering that as a permanent fix. The last thing you want to do is is give the manufacturer that kind of ammo. "hey man it didn't ship that way'

    I agree with your idea in theory as I have seen slow open valves do all sorts of crazy things. I imagine that a slow open valve by it's very nature is going to compound any ignition problems.

    A spider in an orifice should cause the same problem on each ignition. I am guessing there is no air adjustment capability.

    Is this happening with the blower off or on?
    What drastic problem could putting a fast opening gas valve cause? Most induced draft furnaces have them, they must not be too dangerous.

    As for the liability end of it, if there is an incident and lawsuit, it won't matter if you installed the exact part. The manufacturer will still say it is the technicians problem. You didn't tighten the gas valve to the proper torque, you didn't use the right thread sealing compound/technique, you dropped it before you installed it, etc. etc. etc....

    You take on the liability as soon as you touch it.

    Do you test every furnace/boiler you touch for CO levels in the flue? If not you are taking a huge liability risk, way larger than simply installing a universal part. Some of the most dangerous furnaces I have found started out as a simple bad igniter or some other repair. If I hadn't tested and someone died, I would be in serious trouble. My combustion analyzer goes with me into the house on every service call right along with my ticket book and tool bag. I have seen 20 ppm ambient CO in 2 boiler rooms in the last 2 weeks alone.

    And I also agree that the partially plugged orifice could be causing this problem. I would check that before trying a different valve.

  12. #12
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    Quote Originally Posted by 71CHOPS View Post
    is the outlet pressure on the new valve still 2.5-3.5?? that 7" is kinda teetering on the low side of usefulness. check the valve specs for minimum input ratings.

    Has the gas company done any work in the area that may have lowered main line pressures??

    second the efficiency question too.....80%, 90%??
    I think most valves are fine down to 5" incoming. As long as it doesn't drop below that with all gas appliances running. On LP I like to see a minimum of 12"

  13. #13
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    Quote Originally Posted by Glennhvac View Post
    That could be opening up a law suit if you are considering that as a permanent fix.
    Little known fact, from the moment you touch a furnace, you're "it" until the next sucker comes along and tags in.
    If more government is the answer, then it's a really stupid question.

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