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  1. #1

    Need some advice

    I have a Lennox Pulse furnace that is 19 years old and it has quit working. Had the Lennox repairman out and he concluded that a new unit is in order. He was unable to detect the reason why it isn't working. Here's my problem. I know very little about furnaces and he offered three alternative ways to go. The a/c unit is the same age as the furnace but is working fine now.
    1) Replace just the furnace and keep the old a/c until it dies. Cheapest alternative.
    2) Replace both the gas furnace and the a/c unit.
    3) Replace the whole system with a Heat Pump with a gas furnace for backup in extremely cold whether. We live in Central Nebraska and it gets coooolllddd out here.
    The third option would be the most expensive but I understand the heat pump is considerably more efficient and would pay for itself in a few years. I would appreciate any advice as to which choice I should make. Thank you!

    Neal

  2. #2
    Join Date
    Jun 2007
    Location
    The Twilight Zone
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    2,964
    What is your delivered electric rate (cents per kw-hr)?

    What is your delivered natural gas rate ($ per therm)?

    Good luck.

  3. #3
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,706
    heat exchanger in a 19 yr old pulse is still under warranty, why replace it just because he can't fix it??????


    get a lennox dealer with training on the pulse and get it fixed. if the heat exchanger is bad lennox will sell you a 90% furnace CHEAP and you pay to install it.

  4. #4

    rates

    Thanks for the replies. Here are the rates as quoted by the utilities.
    Electric: Summer rate 8.51 cents per KWH up to 750 kwhs. Over 750 KWH 6.90/KWH.

    Winter rate 6.26 cents per KWH up to 750 KWH. Over 750 KWH 3.74/KWH

    GAS: $1.40.8/ therm.

    I will check with the local Lennox dealer about the warranty thing, although I had a Lennox dealer service man tell me he couldn't fix it without tearing the whole thing apart. Apparently he checked everything that he could access without getting into the guts of the thing.


    Neal

  5. #5
    Join Date
    Aug 2008
    Location
    Indianapolis
    Posts
    41
    If he is a lennox guy he should be able to tell you about the lennox programs for the pulse furnace. You should find out what is acctually wrong with it and the exact cost to fix, you could be spending a lot more than you need to right now. Not a big fan of pulse and dont really like working on them but you need all the options.

  6. #6
    Join Date
    Nov 2007
    Location
    Westlock, Alberta, Canada
    Posts
    57
    Have him pressure test the exchanger, damn near guaranteed to leak, then you get a new high efficient furnace cheaper. Also, replace the A/C at the same time.

  7. #7
    Join Date
    Aug 2008
    Location
    Indianapolis
    Posts
    41
    If I pressure test 20 a month through winter maybe one fails. Agreed a new system is in order but he needs to buy it cause he needs it not because someone wont/cant fix it

  8. #8
    Join Date
    Jun 2007
    Location
    The Twilight Zone
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    2,964
    Quote Originally Posted by mountainrivers View Post
    Thanks for the replies. Here are the rates as quoted by the utilities.
    Electric: Summer rate 8.51 cents per KWH up to 750 kwhs. Over 750 KWH 6.90/KWH.

    Winter rate 6.26 cents per KWH up to 750 KWH. Over 750 KWH 3.74/KWH

    GAS: $1.40.8/ therm.
    Neal:

    Compare the cost of 1 million btus for heat pump vs gas furnace.

    Gas at $1.41 per therm, 90% efficient furnace:
    (1,000,000 / 103,000 btu per therm) x 1.41 / .9
    = $15.21

    Gas at same price, 80% efficient furnace
    (1,000,000 / 103,000) x 1.41 / .8
    = $17.11

    Heat pump with electricity at $.07 per kw-hr, C.O.P. (Coeff of Perf) = 3.25 at 35F ambient:
    (1,000,000 / 3414 btu per kw-hr) x .07 / 3.25
    = $6.31

    Your electric rates are dirt cheap.

    The heat pump costs 241% less to operate than the 90% efficient furnace (15.21 / 6.31) and 271% less to run than the 80% gas furnace.

    Since the C.O.P. increases with higher ambient temps, the heat pump will be even less expensive to run as the ambient increases from the 35F example above.

    Note that the cost of a defrost cycle for the heat pump is not included.

    Good luck.

  9. #9

    Thank you Gary G.

    That is an amazing difference in operating costs. I will first check on the warranty situation, but if that isn't an option, I think we will go with the heat pump with a small gas furnace backup in the event of extremely cold weather.

    I have read some reviews of Lennox heat pumps and most people have been very dissatisfied. I know that people who have experienced problems are more likely to write negative reviews, so I am curious what others think of the various brands of heat pumps. Any suggestions will be appreciated.

    Neal

  10. #10
    Join Date
    Dec 2007
    Posts
    96
    Lennox heat pumps are just as reliable as Trane, Carrier,etc. Most people only write something if they are upset. Watch this forum long enough and you will see that. I would stay with Lennox to take advantage of warranty. The first thing you really need to do is to get a Lennox dealer to do a pressure test on heat exchanger. In my area we see about 90% failure rate in pulse heat exchanger if made before 1990. If it does leak Lennox with give you a nice little credit towards a new furnace and even a higher credit towards a variable speed new furnace. The pressure test should be your first move and someone should be able to tell you why it is not working. That way if it does pass the test you will know what repair cost are. Call a Lennox Premier dealer. Look on there website for one in your area.

  11. #11
    Join Date
    Jun 2007
    Location
    The Twilight Zone
    Posts
    2,964
    Quote Originally Posted by mountainrivers View Post
    That is an amazing difference in operating costs. I will first check on the warranty situation, but if that isn't an option, I think we will go with the heat pump with a small gas furnace backup in the event of extremely cold weather.

    I have read some reviews of Lennox heat pumps and most people have been very dissatisfied. I know that people who have experienced problems are more likely to write negative reviews, so I am curious what others think of the various brands of heat pumps. Any suggestions will be appreciated.

    Neal
    Neal:

    If you know the model numbers of the heat pump condenser, matching indoor coil, and furnace, you can go to www.AHRIDirectory.org and check performance and btu ratings.

    For a heat pump, you want 12 EER, 9 HSPF, and full btu's in heating at the 47F rating temperature (anotherwords 3 tons should be 36,000 btu, not 32,000 as some combinations are weak on heating btu's). As for SEER, 15 and below are generally single stage, 16 and higher use 2-stage condensers.

    FYI:
    Heat pumps do not produce the hot 120F air of a furnace. They produce temps in the mid 90's, and their output temps drop with decreasing ambient temps. Also, the life expectancy of a heat pump is less than that of a straight a/c condenser because they run thru all 4 seasons.

    Take care.
    Last edited by gary_g; 09-12-2008 at 11:37 AM. Reason: Added FYI

  12. #12
    Join Date
    Aug 2008
    Location
    Indianapolis
    Posts
    41
    Lennox makes a solid heat pump especially their higher end stuff but then again evryones higher end units seem to be really strong.I know Lennox has a lifetime warranty on their compressor in some of their heatpumps but again its the higher efficency units. Get the pressure test and find out whats broken. Its a lot of money for a new system so do all the research you can, you wouldnt buy a car just cause everyone says its nice.

  13. #13
    Join Date
    Aug 2008
    Posts
    27
    hi
    I am from Canada the winter here is very cold -35c and last about 6-7 months long, I have see many of you mention about "Heat Pump" and sounds like it does save a lot of money on fuels, can I get some advice, what is the different between "Gas Furnace" and “Heat Pump”? It is because we are all using gas furnace over here. Is that any reason?

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