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Direct vent piping

ChrisJ
ChrisJ Member Posts: 15,583
This is my dad's furnace that keeps having pressure switch failures. Altitude is 1900ft and the pipe length and 90 count is near the max recommended by the manufacture.



What are the chances this is what is causing the pressure switches to fail or what are the chances the inducer is getting weaker with age? This is a 80k input Luxaire furnace from 2006 running on LP gas.



The first switch lasted 3 years and all of the new ones have only gone a year or so. He would call the installer back out but his concern is the guy will just install a new switch and leave everything alone. The furnace will give an open pressure switch error which will go away if you tap the switch with a screw driver handle. Replacing the switch fixes the problem for another year but seems wrong to keep happening.



Should this be repiped using mostly 45s, or even enlarged to 3" pipe? Is there any reason not to use 45's and have the pipe on an downward angle back towards the furnace? If it should have a new inducer installed, or be repipped he is willing to get it done but wants to know what to do.



As always I appreciate your help! Welcome any and all opinions.
Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

Comments

  • Does this model have a clear condensate pan.

    When those models came out, around your time of install, they had an incorrect hose system that went into the pressure switch. To fix the problem, you have to get a slightly longer hose and create a loop in it to prevent condensate getting trapped in the pressure switch.
  • bill_105
    bill_105 Member Posts: 429
    Hi Jake

    Just curios, is the namestake ,from State Farm,have anything to do with the Insurace co.?
  • Hi Bill,

    Just an inside joke among my buds!
  • ChrisJ
    ChrisJ Member Posts: 15,583
    Pan

    Hi Jake,



    I asked my dad to have a look, will get back to you with the info.

    I'm assuming any piece of silicone hose the right size would work for this?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • yes of same material

    The ones the factory would give us were long enough to make an upright loop- like a roller coaster and not a trap.
  • ChrisJ
    ChrisJ Member Posts: 15,583
    Serial number?

    Hi Jake,



    Again thanks for responding I really appreciate the help.



    Is there any way to tell by serial number or anything? Or any easy way to see the condensate pan without pulling things apart?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • model # tm9***** i think around 2006-2007

    Easy to see the condensate collector pan on this unit . Open the top door of the furnace, look behind the ventor motor. If what the ventor motor is connected to is a large clear plastic assembly, this may be the style of furnace In discussion. Later, the factory corrected the issue. If the ventor is connected to a brown or black assembly, thats a different model. Keep in mind though that your problem still could be condensate getting trapped in the hose or the pressure switch itself. When you tap the switch you are releasing the vapor-lock. Just my thoughts, glad to help.
  • ChrisJ
    ChrisJ Member Posts: 15,583
    edited January 2014
    GM9S080C16UP11

    Description

    080BTU 16CFM 90% 1S UH CHAMPGN



    Serial Number

    WOK6972703



    MODEL NUMBER

    GM9S080C16UP11



    INSTALL DATE

    12/29/2006



    I finally did what I should have in the first place. Here are pictures of the furnace and behind the top door.



    The ventor is connected to a brown plastic assembly so I guess it's different. My question is, being that hose travels way down how could it be looped and not create a trap? Or is this just a totally different setup then you were thinking?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Hmmm.... older model.

    Do you still have The owners/install manual? It should show on the exhaust venting above the furnace a condensate drip tee. This is needed on long horizontal runs to prevent exessive moisture in the vent motor assembly. I am still leaning towards a moisture issue. I think if the venting was too long you would have a problem all the time. And when Piping is too long the pressure switch doesnt ever close.
  • ChrisJ
    ChrisJ Member Posts: 15,583
    Moisture

    Hoses have always been completely dry whenever the switch was removed. Switches have also not shown any signs of condensate.



    The piping is 25' long but being he is at 1960 feet altitude and it has all of those elbows I think it puts him near the maximum allowed. I think they draw the line at 2000 but I'm thinking 1960 is close enough.



    I really wish I had a real manometer. I have a pocket Bacharach draftrite but I doubt its any good for things like this.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • It would help to know the pressure

    If you are unsure of the venting, you should check the pressure difference on both tubes leading to the pressure switch. Look into installing a condensate drip tee, just saves alot of headaches. If you take the hose off the top condensate dam on the pvc pipe inside the furnace,it usually has shavings in it preventing condensate to drain. when too much condensate gets trapped in the ventor the furnace goes out open p. switch. Just other things to look for if you have boarderline venting.  The installer who put this in should know where to draw the venting line.unless its a wind issue.