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Optimal Settings for Munchkin 199 with Vision 1

When we first installed this system, the boiler seemed to turn on and off almost constantly and our gas bills were sky-high.  I started researching the settings for the system and found that the Munchkin differential was set at only 5 degrees F... hence the constant on and off.  I changed the differential setting to 30 degrees F and our gas bill dropped dramatically without any noticeable change in performance.

Now I'm wondering about other ways I can optimize the settings for the system.  We have a 5,000sf home with so-so insulation, in an area where the winter temps can fluctuate dramatically in a single day...  January might be 15F when you wake up, but rise to 50F or more mid-afternoon.  There is usually a large call on the system early in the morning before everyone wakes, but otherwise the demand is fairly even.

Any suggestions on how to maximize efficiency by altering the Central Heating Curve or other settings?  I am familiar with how to program the system.

Also, curious about pros and cons of having a high Munchkin max temp... I recently discovered our max temp was set at 135F... wondering if we would do better at 180F or more.



  • Zman
    Zman Member Posts: 7,136
    Low temps

    Condensing boilers are most efficient when the return water temps are low. Less than 130 is good. the lower the better. It sound like you have in floor. Is it in concrete?

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
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