Page 1 of 2 12 LastLast
Results 1 to 13 of 14
  1. #1
    Join Date
    Mar 2008
    Posts
    7

    VIsion Pro 8320 and 2nd stage control

    I have studied the Honeywell online documentation and searched this site, but it isn't clear how this thermostat controls the second heat stage. Lots of mumbo jumbo about integral porportional control. My question is, is there a way to adjust how/when the 2nd stage comes on with this thermostat (I'd rather set it myself than rely on a universal, one size fits none algorithm)?

    If not, are there any thermostats that offer this feature?

    Another feature that seems useful is running the fan a few minutes after the condenser has shut off.

    Thanks,
    Tom

  2. #2
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    66,818
    No, there is no way to program it to bring on the seconcd stage heat by time.

    I believe WR has that ability.
    Is your system a heat pump or 2 stage furnace.
    Contractor locator map

    How-to-apply-for-Professional

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

  3. #3
    Join Date
    Mar 2008
    Location
    Houston, Texas
    Posts
    352
    Quote Originally Posted by lapsmith View Post
    I have studied the Honeywell online documentation and searched this site, but it isn't clear how this thermostat controls the second heat stage. Lots of mumbo jumbo about integral porportional control. My question is, is there a way to adjust how/when the 2nd stage comes on with this thermostat (I'd rather set it myself than rely on a universal, one size fits none algorithm)?

    If not, are there any thermostats that offer this feature?

    Another feature that seems useful is running the fan a few minutes after the condenser has shut off.

    Thanks,
    Tom
    The VP stat is one of the very best for many applications, but the heat2 is done from temp difference. The good thing about the 2 stage heat is it can normally run on low heat for twice the time while using 1/2 the fuel. This saves you money and (in most cases) provides more comfort.
    If you in stall some zone systems it can be cycled with time. You may also want to check the furnace. Most of the VS setups have ramping that can also be useful.
    The running the blower after the condenser turns off is normally built into the furnace and in most cases not adjustable. Unless it's an older carrier, they love to let the blower run, which hasn't made them very popular in the higher humidity areas.

  4. #4
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    The Vision Pro's P+I setpoint control algorithm "learns" how to control the staging to maintain the set point. There is nothing adjustable about it, as manual adjustments would defeat the purpose of the P+I algorithms.

    IMO, the Vision Pro thermostats have the best control of staging, to maintain the set point, of any thermostats in the industry.
    Why would you want it to get 1-2 below the set point before 2nd stage kicks in?
    If more government is the answer, then it's a really stupid question.

  5. #5
    Join Date
    Nov 2003
    Location
    Rochester, New York
    Posts
    392
    Quote Originally Posted by Skip 2 my lou View Post
    The VP stat is one of the very best for many applications, but the heat2 is done from temp difference. The good thing about the 2 stage heat is it can normally run on low heat for twice the time while using 1/2 the fuel. This saves you money and (in most cases) provides more comfort.
    If you in stall some zone systems it can be cycled with time. You may also want to check the furnace. Most of the VS setups have ramping that can also be useful.
    The running the blower after the condenser turns off is normally built into the furnace and in most cases not adjustable. Unless it's an older carrier, they love to let the blower run, which hasn't made them very popular in the higher humidity areas.

    Running on low fire DOES NOT SAVE YOU MONEY!!! 2 stage furnaces are in all cases for comfort only. Don't confuse the guy.

  6. #6
    Join Date
    Mar 2008
    Posts
    7
    Thanks for the replies. I think 2 stage will save me a small amount of money (fewer starts and stops mean less time to reach operating temp before turning on the fan, and also less wasted heat cooling off). But I agree, it won't be much savings.

    I don't want to go 1-2 degrees below setpoint before turning on the second stage, but I also don't want it coming on too early, which is what I'm afraid of.

    Also, I just found out the installer can't get the Rheem single-speed 2 stage (furnace) that I wanted for 5 weeks. Looks like I'll have to go with variable speed...or just go with the single stage single speed and save some money.

    Tom

  7. #7
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304
    I been a proud owner of the Honeywell two stage stat for 3 1/2 years, and it had done a great job keeping temp in the home.

    I love the long run time in 1st stage in the winter months, and cycle 2nd stage as needed when it gets down to -10˚

    No way i would want the swing as you may see in the other guys' stat.

  8. #8
    Join Date
    Mar 2003
    Posts
    7,314
    These newer systems are designed for better occupant comfort. A two stage unit will run longer at a reduced firing rate. The longer run times will offset most of the savings of firing at a lower rate, but BTU's are BTU's. The only savings incurred will be stack losses in most cases, and the efficiency gained over the old equipment. The benefit though is overall comfort. The newer unit will run at a reduced temperature rise, causing less scorching of the air, which helps with indoor RH and it will also keep temps more stable. The Honeywell stat, in my opinion is by fat the best choice right now, and from what I can tell the best product they had in YEARS. They have built some fine algorithoms to run your home and keep you comfy. Let it do its job. While its more costly than others, its justified.

  9. #9
    Join Date
    Mar 2008
    Location
    Houston, Texas
    Posts
    352
    Quote Originally Posted by local 832s View Post
    Running on low fire DOES NOT SAVE YOU MONEY!!! 2 stage furnaces are in all cases for comfort only. Don't confuse the guy.

    Of course running twice the time using 1/2 the fuel doesn't save money. Unless you look at it from the old standpoint. The old units run for 5 minutes and stay off for 10. The 10 minutes it is off you get a chill, so you set it higher to compensate. Thus using more BTU's and more money.

  10. #10
    Join Date
    Mar 2008
    Posts
    7
    I came across the Venstar (sp?) line of thermostats and the T1800 and T2800 (commercial version) seem to have very good control and adjustablility of the stages.

  11. #11
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304
    Quote Originally Posted by lapsmith View Post
    seem to have very good control and adjustablility of the stages.
    Why do you want adj in stages?

  12. #12
    Ive had a similar prob with honeywell 8000 series, second stage with dual fuel ONLY engages when balance point drops below setpoint....no matter how low the house temp gets! Junk! Damn it CARRIER! why did you do away with a good dual fuel stat!

  13. #13
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304
    Quote Originally Posted by limahvac View Post
    Ive had a similar prob with honeywell 8000 series, second stage with dual fuel ONLY engages when balance point drops below setpoint....no matter how low the house temp gets! Junk! Damn it CARRIER! why did you do away with a good dual fuel stat!
    ??? You're talking two brands here...

Page 1 of 2 12 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