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  1. #14
    Join Date
    Jan 2005
    Posts
    340
    Originally posted by jim15102
    I did not close the vents the installer did to force air to the rooms I was complaining about! I did not know this would cause a problem.
    Now you do, so you should open them.
    Originally posted by jim15102
    I also understand the two stage furnances, the problem like I said before its that on the first stage (which is most of the time) the house is cold even with the thermostat set at 71. On high fire the house is very comfortable.[/i]
    This isn't an indication that the furnace is undersized. In fact, it may be that the furnace is sized correctly, perhaps even a little oversized, and that your thermostat just needs to either be set higher and/or be set with a smaller deadband.
    Originally posted by jim15102
    The reason I do not think this furnace is correct for my house is that I used 16 MCF's (bills are always actual) to heat my house last month. That is more than my 32 year old 130,00 btu furnace ever used in a single month. And the fact that most other estimates were between 70k and 80k furnaces.[/i]
    It has been a cold winter in most of the country. How do your heating degree days for this billing period compare to last years? Also, are your new windows more energy efficient than your old ones, or the other way around?

  2. #15
    Join Date
    Aug 2004
    Location
    Great White North
    Posts
    92
    Jim: I wouldn't take any comments here too personally. I doubt anyone is being rude or ignorant with you. More like just quick and to the point. So many of these questions have been answered a multitude of times it's almost unbelieveable.

    Anyway...here's my 2 cents...and fyi, I'm a home owner and not an HVAC tech.

    The load calc says 60K is the right size for your home? Then 80K isn't the answer. The right size is the right size. Putting in a bigger unit for naught will potentially cause you more problems like short cycling. If they are suggesting a two stage 80k unit, then what's really going to happen is the new unit will run on low fire the majority of the time if not always...but that's just because low fire on the 80k is not far off of high fire on the 60k.

    You also say the furnace won't heat the house up on low but does fine on high. That alone almost verifies (almost) you have the right sized furnace (house heats okay on high). What's also fine is that if it is colder outside, low is not expected to be able to handle the task...that's why there's a "high". Not sure how much you know about the mvp but it should start on low fire and if the temp rise is too slow, it will automatically change up to high fire. When it gets close to the set temp cut off, it will roll back to low fire and finish off the heating cycle. Does your furnace do this? Maybe your unit was set to run on "low fire" only and now someone has set it to run on "high fire" only. If it was set to "low fire" only, it would take forever if ever to heat your house up properly. If someone has set it to "high fire" only, then it will always be up to the task but them what's the point of having a two stage furnace?

    Also, if you don't have a two stage thermostat, you might want to consider one. It works better than the single stage thermostat using the logic of the furnace. Maybe an Infinity Control should be hanging on your wall if it isn't already.

    Let us know what's what.

  3. #16
    Join Date
    Jan 2005
    Posts
    340
    Originally posted by jim15102
    The reason I do not think this furnace is correct for my house is that I used 16 MCF's (bills are always actual) to heat my house last month. That is more than my 32 year old 130,00 btu furnace ever used in a single month.
    Gas consumption has very little to do with the size of the furnace. 1000 CF of natural gas = about 1.027 million BTU at 100% efficiency. Derate by the efficiency of your furnace.

    [Edited by travisfl on 02-01-2005 at 02:40 PM]

  4. #17
    Join Date
    Jul 2001
    Location
    Gold Coast of Connecticut
    Posts
    4,543
    Hey Jim,

    I think you may have other issues with you gas consumption other than too small of a furnace. You can set a 2 stage unit to cycle with just the high fire rate and see if you like it better. I suspect you have a major duct problem or an air distribution problem. I would double check for gaps in your ductwork to make sure you are not sucking return air from unconditioned space. Also the temps and wind have been a bit more extreme this yaer than many past years in Connecticut any ways.

    As to sizing your unit if high fire does not run constantly you have the correct size unit.
    Aire Serv of SW Connecticut- Gas heat, dual fuel and central a/c systems installed and serviced

  5. #18
    Join Date
    Jan 2005
    Posts
    6
    I do have the infinity control. Also high fire normally takes about 10 minutes to get the house back to temp.

    Let me explain my problem:
    The themostat reads 71. Every room except where the thermostat is (hallway no vents) is atleast 4 degrees less. I bought a thermometer and put it next to the thermostat to verify it was working correctly then tested all the rooms. I even moved the thermostat to a different room and got the same results.

    If I turn the thermostat to 75 degrees the house is warm but then my bills will be huge. I didn't have this problem with my old furnace.

    Again thanks for all of your help.

  6. #19
    Join Date
    Oct 2001
    Location
    Waterford Michigan
    Posts
    2,668
    If your dealer can't figure this out it's no wonder your having problems.

  7. #20
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,755
    JMO, you have an air distribution problem, not a furnace size problem.

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    How many times must one fix something before it is fixed?

  8. #21
    Join Date
    Aug 2001
    Posts
    220
    You need make sure the tstat in not located too close to a supply air grille, or in a bad location where it is not sensing the average temperature of the house. Near a return is normal, but for it to be reading +4 from the rest of the house seems as it might be too close to a supply grill. If thermostat location is OK , you could always get a tstat that accepts remote sensors . Put a remote sensor in the rooms of different temps and if will cycle based on an average temp. If everywhere else in the house is the same temp except for where the tstat is located,then it probably is just a bad location. If you have different temps all over the house then possibly a poorly designed duct system. If they have been building several of these houses with no problems then they probably have a adequate duct design,or else you would not be the only one with problems. Which means your ductwork could have been damaged somehow. There are a lot of things to look at before you should let them change the furnace is my point....

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