Page 1 of 3 123 LastLast
Results 1 to 13 of 33

Thread: Lennox Pulse

  1. #1
    I have a Lennox pulse manuf in 12/89 and according to Lennox, it does not fall under the recall on the heat exchanger. I have never had any problems with it other than sometimes it will come on for 10 sec and then shut off. I have not had it serviced in a while, so I am having someone service it soon. Per Lennox I am having the gas flapper and air flapper serviced, and pressurizing the heat exchanger to ck for leaks. Can anyone think of anything else that I should have done when the tech comes to service it?

    Also, can someone give me an idea of how long this furnace might last, and whether it is worth keeping it? I have kept the air filters changed religiously.

  2. #2
    Join Date
    Nov 2001
    Posts
    1,874
    the only other item to service is the drip leg on the drian line,
    Some have a rubber cap at the bottom, if it yours doesn't he'll need to cut the PVC and glue back a 1 1/2 " coupling.
    The air flapper is the main cause for concern.

    As far as lentgh of service, my brother and uncle both have one. I keep an eye on them. But they are both running as factory intended today. If it passes the test, keep it.But have it checked every yr.

    Also another thing to have your guy look at is the secondary heat exchanger.
    Have him pull the blower and see if it needs cleaned. This will only take about 15 minutes of his time.

    good luck,
    If you try to fail, and succeed.
    Which have you done ?



  3. #3
    Join Date
    Aug 2002
    Location
    manitowoc wisconsin
    Posts
    4,943
    Toolpusher has it covered,good advice.
    Take your time & do it right!

  4. #4
    Thanks a lot for the information.

    Bill

  5. #5
    Join Date
    Jul 2002
    Location
    St Paul, Minnesota
    Posts
    3,468
    Make sure the intake and exhaust do not recirculate. Both pipes should be at least 12" apart. The exhaust should have a reducer on it and you may have/put a 90° elbow on the intake. Also make sure the holding straps stay secure so there is slope back to the furnace on the exhaust and there are no leaks at any of the joints. When in the intake chamber, put a drop of oil on the motor shaft to prevent rust. Check gas manifold pressure.

  6. #6
    Join Date
    Aug 2001
    Location
    Phila,Pa
    Posts
    150
    Hire a lennox technician and not a carrier or york.
    They probally don't have the proper tools to test heat exchangers.

  7. #7
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    I did hundreds of the pressure tests on Pulse furnaces for the last company I worked for, I found 8 or 9 that leaked. I think the total failure rate was less than 3% last I knew.

    If your furnace was built after the cutoff date, the proccess for attatching the the stainless and mild steel parts of the heat exchanger was different and shouldn't be a problem. Unless something new has been found out in the last 3 years or so.

    If furnace hasn't had the gas and air diaphragms changed, or the spark plug and flame sensor, its definatly a good idea to go ahead and do that now. There used to be an update kit that changed the gas oriface and pressure regulator along with the diaphragms, but you may not need one if its a G21, GS21, or GS21V furnace. All G14 and GS14 furnaces should have the update kit installed if its still available. The revised gas presure regulator and oriface make the units operation quieter.

    Just about every problem with a Pulse furnace can be diagnosed by listening to the unit.

    Your best bet is to find a Lennox dealer that services them, as there are a few special tools and knowledge involved that you are unlikely to find from other dealers.

    The problem with the fan coming back on briefly after a heating cycle is usually caused by a dirty secondary heat exchanger, but any restriction to the airflow can cause it, dirty blower, coil, filter, poor duct system, etc. The heat exchanger isn't cooling down enough, so the air temperature goes back up inside the furnace and the thermostatic fan control turns the fan back on.

    The problem can also be caused if the heat assist in the fan control has failed, someone monkied with the settings of the control, the fan control itself is going bad, or if someone installed an incorrect fan control that doesn't have heat assist.
    The unit should have a 7" insertion ChamStat fan/limit control or a 5" insertion Honeywell fan/limit control. They are interchangable, the opening in the unit is shaped to talke either one and there are predrilled screw holes for both. The important thing is that it MUST have heat assist for it to work correctly.

    Overall, I would have to say that the Lennox Pulse furnace is the most reliable resadential furnace I have experience with. Most of the problems I have seen with them were due to lack of maintenance or incorrect installation of the vent and drain systems.

  8. #8
    Thanks for the insight. The service tech could not get the gas flapper to come off. He said it was attached to the heat exchanger and if he put too much force , that it might break the heat exchanger, so he left it in. This is a propane system and might be contributing to it being frozen. Would Lennox provide a furnace to me if the gas flapper was not able to be removed to do the pressure test, or would they require the tech to test the heat exchanger with the gas flapper still installed. Do you suggest that I not worry about the gas flapper valve since the furnace works fine? Would Lennox provide a free replacement furnace if the Lennox recommended routine maint., like replacing the gas flapper every 4 years was not possible without breaking the heat exchanger? What would Lennox do if my heat exchanger broke while trying to replace the gas flapper valve?

    Thanks

  9. #9
    ...All you have to do on the gas diaphramn is back it up with a wrench and use an electric impact. It will pop right off with no damage.

    ken

  10. #10
    Originally posted by ken from nw ohio
    ...All you have to do on the gas diaphramn is back it up with a wrench and use an electric impact. It will pop right off with no damage.

    ken


    The tech had the large 1/2 inch drive socket on what he said was the gas flapper valve. I looked at it again today, and there is nowhere that a wrench could fit onto behind it. There is a big red grommet directly behind what he had the socket on.
    He took off the 90 deg elbow that has the square drive service plug installed in it for a gas pressure guage to be installed into, and then a 2-3 inch straight piece of pipe, to the left of the elbow was unscrewed from what he said was the gas flapper valve. Then he put a large socket on what the short 2-3 inch pipe had screwed into. On the left side, there is a big red rubber grommet where this pipe enters the inner cabinet. This is what he was trying to remove with the big socket. It appeared to be part of the heat exhanger assy, not a removable part. I saw a sticker on what looked like a condenser, that said to use 2 wrenches when removing the gas flapper valve. I am not so sure he was trying to remove the gas flapper.

    I have a pic of the heater I would post, but I can't figure out how to post it.

    Do you have any ideas about what he had the socket on?

    Bill

  11. #11
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    He had the socket on the correct part, he just lacked desire to get it off...

  12. #12
    ...very true Mark !

  13. #13
    Join Date
    Feb 2004
    Posts
    175

    Cool

    Trust the advise of the pulse experts. Lack of desire is correct. He's probabily not experienced with a pulse and is afraid of damging it.

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event