Results 1 to 12 of 12
  1. #1
    Join Date
    Dec 2004
    Posts
    23
    Hi,

    Just a few month ago I installed new high efficiency furnace and today it failed. The inducer motor would start for about 30-40seconds, then furnace would shut down. Error message indicated that there was a problem with high preassure switch.
    As this discussion group helped me here before, I want to share my experience on how it was fixed. I was told that this is very common problem.
    I live in Toronto, Canada and here we had very cold few days. I checked outside vents in/out and there were some ice around out vent, I removed it but there was big chunk of ice left on ground and it was touching pipes, just touching, not obstructing holes. When HVAC guy came, he said that if ice is touching pipe, it would make it freeze very fast and you have to remove any contact between ice and vent pipes. We did just that.
    Another thing was that HVAC guy checked all small tubes (for aird) inside furnace that goes into preassure switch, disconnected them and just blew into them to take dirt out.
    That was enough to fix and furnace started to work.
    Just sharing this info if anyone else will have similar problem.

    Thanks


  2. #2
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    Furnace is a few months old and has dirt in pressure switch hoses? I think they will be back to try again.

  3. #3
    Join Date
    Apr 2004
    Posts
    7,680
    My question would be is it vented properly? Then, I would say he probably recycled the power and reset the fault.

    Tell us the model number and brand then explain the vent in detail (diameter, length, hight, number of elbows, vent material etc.)

  4. #4
    Join Date
    Jan 2005
    Posts
    56
    I ran into a similar problem a few years ago. Whoever the contractor was didn't allow any "slope" in the pipe and ice formed about 12" inside the flue pipe! Replumbing the flue did the trick.

  5. #5
    Join Date
    Feb 2004
    Location
    Ontario
    Posts
    700
    You probably had frost built up inside the intake. I work in your vicinity, and during the recent cold spell saw several like this. Sometimes it's hard to know if you've got the frost clear if the intake has a 90 elbow. Recirculation of flue gases into the intake causes the frosting, the swirling snow we had would contribute. Possibly the ice build-up would contribute too. You should check your installation manual very carefully to see that the vent and intake slope, length, size, configuration, location and termination arrangements are exactly according to spec. Even then, it's possible with the right weather conditions for it to frost up, but much more unlikely.
    Question authority!

  6. #6
    Join Date
    Dec 2004
    Posts
    23
    Hi everyone,

    OK I checked my pipes and they do not slope towards furnace! They are actually slope just a bit from the furnace! So know I believe I know why there was so much water comming out of my vent pipe - it was not able to run back to the furnace as it should!
    Thanks everyone for your comments. I already called my installer and they should call me back and we will arange time for them to fix problem. I hope they will not tell me that this is not a big deal.

    Thanks again for all the help you guys provided.

    VM.

    Note: I have Carrier Infinity MVP58 furnace 100BTU, blower size 20. My venting pipes are of PVC material, 6 90 degree turns, 1 45 degree. Pipe diameter is 2-1/2. My pipe lenght in total is about 20 feet. Based on documentation I believe I could have up to 70 ft length. So I hope othervies furnace is vented OK.





  7. #7
    Join Date
    Sep 2001
    Location
    East Stroudsburg, PA
    Posts
    13,215
    Originally posted by trane
    Furnace is a few months old and has dirt in pressure switch hoses? I think they will be back to try again.
    That's a sign of a really bad installation.

  8. #8
    Join Date
    Feb 2004
    Location
    chicago suburbs
    Posts
    4,422
    how about some pics of installation.
    FILL OUT YOUR PROFILE!!

  9. #9
    Join Date
    Jul 2004
    Location
    midwest
    Posts
    2,868
    Originally posted by tinner73
    how about some pics of installation.
    Are you sure you want to see them? If these guys don't know how to run the flue pipes out it makes you wonder what else they don't know about. I don't want to make this home owner worry but I would bet this is one of the easy sections to understand in the installation instructions.

  10. #10
    Join Date
    Dec 2004
    Posts
    23
    OK,

    Now I am really angry. I was sitting this evening and reading how to install furnace, were I was supposed to enjoy my time with family.
    This is what I found now is bad with my installation:
    1. Vent pipes are terminated about 1 inc from outside air conditioning unit. Installation manual states: 'Termination kit should be positioned where vent vapors will not damage plants/srubs or air conditioning equipment'. Now (probably because of no sloping) vent pipe is spraying water directly on my air conditioning unit!
    2. Vent pipes are not sloped toward furnace. Manual states: Slope combustion-air and vent pipes a minimum of 1/4 in per linear ft with no sags between hangers.
    3. My vent pipe is about 12'' above ground. Manual says: Vent pipe clearance should be 12'' above anticipated snow level. If I have 10'' snow (very normal expectation), my pipe will start to such in snow...
    4. Within the furnace they were using the same 2 and 1/2 inc pipe. Manual states: A 2-in. diameter pipe must be used withing the furnace casing. Make all pipe diameter transitions outside furnace casing.

    And this is what I (guy without any furnace knowledge) found so far!

    I was not the cheap bastard, as I knew that installers are as important as furnace brand. I vent with the biggest and most reputable company in Toronto! I wanted this job to be done right. And now I have to spend evenings studying how to install furnace...
    Tomorow I will request that they send me another installer crew. I just cannot aford to pay thousands of $ again to another company.

  11. #11
    Join Date
    Sep 2001
    Location
    East Stroudsburg, PA
    Posts
    13,215
    Go get 'em, bud.

    Wave that installation and operation manual at them and ask them why they feel that they're above following the directions.

    Insist that they make it right.


  12. #12
    Join Date
    Dec 2004
    Posts
    23
    This is just a follow up for my case. Company came in, and re-did all piping. They reduced number of elbows, raised terminations outside of the house higher from the ground and sloped all pipes toward furnace! Now furnace vent does not spray water as it used to be. They also will reline chimney that now has just my natural gas water heater attached. It is 6 in and it was supposed to be relined when furnace was removed.
    Thanks everyone for all your input. You really helped me here a lot!

    VM

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