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Am Stand flame flutter. blowing cold air

Roscoe
Roscoe Member Posts: 23
I have a 3-year old American Standard forced air heating system.  The system consists of (2) units that run in tandem.  They heat an old (1903) large (4500 sq ft) poorly insulated home.  There is a single thermostat/single zone, and the units are wired to run as a single unit.

I have an intermittent problem where the flame of unit 1 will occaisonally flutter and be "blown out".  It doesn't happen on all heating cycles - only on some.  When it does happen, the ignitor will come on and the unit will relight, only to flutter and go out 15-30 seconds later.  This can happen multiple times (5-10?) during a heating cycle - or not at all.

Also - during heating cycles with flame flutter - the fan seems to slow down for a very short period of time (5 seconds?) and then speed up again.  It does not seem related to the exact time when the flame has been extinguished - but I have not been able to 100% confirm.

Lastly - at the end of the heating cycle, the blower will run confinuously for a very long time - up to an hour or more blowing cold air.  This morning the thermostat had been satistifed, but the blower was still running for ever.  I dropper the thermostat setpoint down a couple of degrees, and after a minute or so turned it OFF.  The blower still ran for another 15 minutes before I went into the basement and turned the power to the units OFF.  Fan off delay on both units is set at 100 seconds.

Unit 2 seems to run fine.  They are both fed from a 1-1/4 gas line (new pipe from the meter) that branches to (2) 3/4" lines to feed each unit.  Unit 1 is has a slightly shorter run and is therefore closer to the meter.

The installer has been by multiple times and has replaced the pressure switch (universal unit - not the OEM unit) that he had difficulty wiring, and the combustion chamber blower because it made noise (as it's done since day 1).  He also adjusted the gas valve.  He could not find a port to test the gas pressure, so gave it the old "1 and a half turns" ???  The problem seemed to be solved (did not occur during the next several heating cycles), but of course returned a short time later.

Here's the potential smoking gun - the meter was replaced over the summer.  I had a small, undersized, old meter.  It was replaced with a "485?" after a series of issues with my Alpine boiler.  I was out of the country and the installer convinced my wife to do this - I never would have agreed.  Regardless, this leads me to the belief that it's a pressure problem. 

I called the gas company to check the gas pressure on the downstream side of the meter.  They were getting 7.2" - 8" when the unit was running.  Of course, the flame flutter problem did not occur during the time they were here.  The gas pressure was a bit of a surprise - as the tech said the drawing indicated that the neighborhood has approx. 6" of pressure.  The tech said he felt it was more of a voltage problem than a gas pressure problem.  He also said that the gas valve on the unit did not have a port because they are set by the manufacturer and should not be adjusted.  Wonderful.

Lastly - my gas bill seems to be up 40-50% this season.  Coincidence, or ?

Any ideas would be greatly appreciated.

Comments

  • icesailor
    icesailor Member Posts: 7,265
    edited January 2014
    Checking Pressure:

    You mean that there are no gas drip nipples with caps that the tech can't remove to put a manometer on to check the incoming gas pressure while one or both are running and or stopped?

    Doing the old "one to one & a half turns" on the screw changes the air fuel ratio. Did he put his analyzer on the equipment?

    You sound like you have a control/wiring issue. The other is a fuel issue. If your gas usage seems to be going up, it probably is. If turning the screw in to raise the gas pressure doesn't fix it, it is wrong. If the person doesn't have an analyzer and a device to measure the gas pressure and knows how to use them, find someone who does.

    Some of us find this a rewarding challenge to resolve. Some don't care.

    Also, be sure to check the incoming voltage and polarity when one or both are running. Are they both on the same circuit? If not, are they both on the same leg so that you get 125 volts between the two separate circuits and not 240 volts. If the two are connected, and you have them on separate legs with 240 volts, strange things can happen.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,363
    Gas pressure

    Sounds like gas pressure problem. You need to have the correct gas valve and if you can't check the gas pressure then it shouldn't have been adjusted...your just working blind.

    Could be other problems but I would start there.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,363
    gas valve

    I think he was trying to adjust the GV outlet pressure.
  • Roscoe
    Roscoe Member Posts: 23
    Voltage...

    Thanks for the replies.

    Interesting comment about voltage.  After the difficulties I mentioned with the Alpine - which was caused by a neighborhood power surge - I ran a dedicated circuit to the unit from the breaker box.  The installer had picked up power from two separate circuits - tied into a basement light and from a kitchen receptacle, which I thought was simply lazy work and not done right.  So I put a 20-amp breaker in the panel, ran new Romex to the separate switches that feed the units.

    From my perspective, they were each fed with 115v from two separate circuits, but are now fed with 115v from a single circuit, which should not affect the operation of the units.  What am I missing?
  • Roscoe
    Roscoe Member Posts: 23
    Gas Pressure

    Re. Gas Pressure - the only change in the system was an increase in the size of the gas meter, which should have improved flow.  Not sure how I could have a pressure problem, after 2-3 years with the unit running fine with the old meter.  Could it be a problem with the gas valve itself?  I've looked at the way it's piped - it does not seem to be set up to easily be replaced.  I also do not see a place to measure the gas pressure on the units.

    Other than calling a tech to start replacing parts - any ideas on what I can do?

    Thanks
  • icesailor
    icesailor Member Posts: 7,265
    edited January 2014
    Amps:

    Look at the amp rating of a single unit. It may only be able to be fed from one 20 amp branch circuit. The fact that the lazy electrician chose to wire it like he did from two circuits that were shared by other appliances show me that it was a consideration for him that there be two circuits. If you ran both furnaces off the same 20 amp circuit from the panel, it may be overloaded. You need an Amp Clamp on a feed to the furnaces to see if there is a voltage drop or an amp spike.

    Understand that if you put two 20 amp breakers side by side in a panel, you will have 240 volts between them. You must alternate (have another circuit breaker between them) to make sure that both circuits are on the same leg if they share ANY power between them. Like transformers and thermostats. Where you say that they run concurrently, I always wonder about that problem. I've worked on equipment that was run with 125 volts but had 240 motors for fans. They were fed with a single 240 volt circuit but the separation was internal and you can't screw it up. Unless the electrician is sharp and on his game, it would be easy to mix them up. Especially when I always understood the codes to require separate circuits for appliances such as this.

    I'm not saying. But it is something to be aware of.

    Personally, if you don't own a digital gas manometer that will read negative pressure and a digital combustion analyzer, you don't belong taking off the cover of a gas appliance and futzing around with it.
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    I am confused

    you start talking about your American Standard furnaces (twinned up) with a problem then all of a sudden it is the Alpine Boiler. If you are having problems with all the units then I would suspect gas problems. What is your location in the country? Is the gas to your house a low pressure system? You can tell that if all you have is a gas meter and no pressure regulator ahead of the meter.



    A warning about checking gas pressures on high efficiency equipment do not use a water filled "U" gauge (manometer) use a digital manometer. This is true on all negative pressure gas valves.



    Give me some make and model numbers on your gas valves and I will then be able to give you a little more insight into what they are and how they operate. If you have negative pressure gas valves they must be set by using a combustion analyzer and using the "throttle" control on the combination combustion air blower and the gas valve. Those valves do have a place to check pressure but they are European style test connections and 99 % of the technicians do not even know what they are.



    It is also not a good ide to use any combustion air blower which is not specifically designed for your units.



    It sound like you need to get someone who understands boilers and then a separate HVAC company for the furnaces.
  • Roscoe
    Roscoe Member Posts: 23
    Sorry for the confusion...

    If you look at my orig post you'll see that my neighborhood had a power surge in July.  The furnace is off in the summer, but the Alpine boiler (hot water) is not.  The Alpine was fried.  Everything was replaced 2x before the orig installer could get it running (ultimately a Burnham rep came and pulled everything out and replaced with new to get it going).  During the first round of parts replacement, the orig installer convinced my wife that the problem was the gas meter - so it was replaced (I was out of the country).



    In July I kicked on the Am Standard furnace for a few minutes and all seemed fine.



    Fast forward to October, and the furnace is running all the time, and I've noticed the flame flutter, etc.



    All parts that have been replaced were replaced by the orig installer, as was the gas valve "adjustment".  The only thing I've done myself is to run a dedicated circuit to supply the unit.



    I have low pressure in my area.  The gas company (National Grid) said they believe it to be approx. 6" water column - but when they came and measured on the downstream side of the meter (with the unit running) they said they were getting 7.2 - 8.  They used a water-filler manometer.



    Based on earlier responses, I will rewire the units onto separate cicuits as they were before.  That will probably have to wait until Friday afternoon.  I'll then update the post (late Friday or Saturday) and include model numbers, etc.



    Thanks to everyone for their help. 





    Based on the responses rec'd
  • SWEI
    SWEI Member Posts: 7,356
    Low pressure

    meaning no regulator ahead of your meter?  Did they test with all three appliances running simultaneously?  What about your stove/oven/pool heater/etc?
  • Roscoe
    Roscoe Member Posts: 23
    Low pressure

    Correct - no regulator on the system anywhere.



    There are only 4 gas-using appliances in the home (Am Standard furnace, Alpine boiler, gas dryer, and gas range).  They tested it with both the furnace and Alpine running, as the flame flutter was happening earlier that day when everyone else was sleeping and therefore the range and gas dryer were not operating (I don't cook or do laundry).
  • Roscoe
    Roscoe Member Posts: 23
    Additional info...

    The problem seems to be more acute in the evening and early morning.  I know this is illogical, but I thought I'd mention it just in case. 



    Last night I woke up around 2:30 am and listened to the unit running for about an hour - blowing cold air.  I went into the basement to power cycle the furnace.  Now BOTH units were having the flame extinguising problem. 



    This morning I rewired one of the units to a separate circuit.  The two units are now supplied via Cir 3 and CIr 40.  No change in performance.  The Alpine boiler was running at the same time, so i powered it down - no change.  The only gas-using unit in the house is the furnace - and it can't hold a flame.

    The units are American Standard   AUC1D120A9601AD.

    s/n (of 1 unit) is  10082NBG7G

    The gas valve doesn't have a name/manufacturer on it, but there's a barcoded tag on the top with the following infomation:  1004  A029  -  5001 1406  -  36J22-209



    I can't see how it can be anything BUT gas pressure/volume at this point.  The orig installed is pointing at the gas company.  The gas company came and measured the pressure and says it's fine.  In the meantime, the furnace isn't running correctly, and my gas usage is way up.



    Again, ideas/suggestions much appreciated.
  • Roscoe
    Roscoe Member Posts: 23
    A quick apology if I offended anyone...

    One additional comment related to my earlier post about the "lazy electrician":



    This morning when rewiring one of the units, I decided to run power directly to the Emergency disconnect switch.  When I opened the box, I found that the white common wires were not twisted together, but someone simply stuck a wire nut on it.  When I reached for it I accidentally bumped it with my finger, and the nut fell off and the wires separated.  Also - the 2 ground wires were not connected to eachother or anything else - they were just laying in the switch box.



    I've also found sections of the 4" pvc exhaust pipe unglued.



    Apologies if I offended anyone with my comment.  I know many installers are taking their personal time to educate and help less knowlegable people like myself.  When I found the unit had been tied into a junction box that fed half the kitchen above it, I assumed that the electrician simply picked up power from the nearest possible location. 
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    The fact that you are in a low

    pressure gas area the time frame of problems says that at the high demand periods early in the AM everyone getting up and turning up the heat (high demand) and then in the evening everyone home (high demand) that the main system in the street is perhaps unable to handle the high load demand at those times. I s any one else on your street having the same problem?



    I assume this is a system that is either spark ignition or hot surface ignition so it has to prove the flame once the burner is on. If the pressure is low the flame will not hit the sensor and insufficient microamps will be generated hence a shut down and re attempt will keep occurring.



    That gas valve is a White Rodgers model 36J22-209 I will look it up and see if there is anything unusual about it.



    Some pictures  of the control boards in the units and gas valve would help. That along with the combustion air blower pressure switch arrangement.
  • Roscoe
    Roscoe Member Posts: 23
    Some photos...

    I've taken a Quicktime video of the flame flutter - but cannot figure out how to post it.  Once I get that sorted out I will add it.
  • Roscoe
    Roscoe Member Posts: 23
    Quicktime video of flame flutter

    I hope this works...
  • Roscoe
    Roscoe Member Posts: 23
    Contractor Help

    David



    The contractor who did the install is licensed, but I don't believe permits were pulled for the job.  I am reluctant to call him back (again!) as he believes the problem is related to the gas meter change (that he recommended) and low pressure in the area.  Note that the unit ran fine for 2 or 3 seasons until the gas meter was changed earlier this year.



    If someone could recommend a contractor in the area (if that's allowed) please do.  I am in NY/Long Island/Suffolk County/Babylon. 



    I'll take some better photos tomorrow and post them.



    David - I see your post was edited by the Admin.  If there's more that you wanted to convey, feel free to send me a personal mssg.



    Thanks
  • Roscoe
    Roscoe Member Posts: 23
    PM sent

    David



    I have tried to provide all of the information you've requested.  I've sent it to you via a personal message as not to clutter the forum with additional photos.  Let me know if you need anything additional.



    Thanks again
  • Roscoe
    Roscoe Member Posts: 23
    Additional info sent

    to your email
  • drhvac
    drhvac Member Posts: 189
    checking gas pressure

    Roscoe I'm very familiar with American Standard equipment and the gas valve on that unit definately has a place on it to check gas pressure. As everybody has said, first obvious thing is to make sure the gas pressure is right. I once had a customer call me with a similiar problem on his furnace which was also American Standard, and the problem was the holes in the outlet ports of the gas burners were plugged up. I'm assuming this has been checked by the first guy you had there, but you never know.