3 stage heat, 2 stage cooling thermostat recommendation

Discussion in 'Maintenance and Troubleshooting' started by JohnF, May 21, 2011.

  1. JohnF

    JohnF New Member

    I've had geothermal heat pumps for 16 years, and I have just installed 2 stage CM TT27 with a heat strip for backup. Soon I'll have a second 2 stage CM TT27 (split unit) installed for the second floor. The upstairs unit will not have a heat strip. I'm looking to get new thermostats for both units, preferably same type or similar, so I don't need to read two manuals:)

    As for features, I'd like to be able to control the first and second stage by temp difference, and also by time if stage 1 is not keeping up. As for programming, I'll probably just use nightly setbacks, maybe daily later if I see that it would make sense. So I guess I'd need 7 day programmable unit. As for aesthetics, I like the big touch screen t-stats better than ones with lots of buttons, but that's not as important as functionality. Do any thermostat allow half a degree accuracy and settings? Also I'd like to disable the heat strip at the t-stat, but I can just shut off the breaker. Are there any t-stats that display what's being called for (Y1, Y2, W, etc)? I really like how the CM TT27 control board displays that. Also, can t-stats display errors/alerts from the control board? Am I correct to assume that since the t-stats are replaced about the same time as the geo units they would also be covered by the fed tax credits?

    I tried searching the forum for this and could not find good results, I guess the words are too common or I can't phrase the query correctly. Any recommendations would be greatly appreciated. Thanks.

  2. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I like

    Emerson Electric's White-Rodgers 1F-90 series.
  3. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader


    I have a question that came up through a client on that Emerson thermostat.

    It does not appear to display 3rd stage ( electric) when it comes on. Does it?

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