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Performance data on my Quantum Leap...Boilerpro

Boilerpro_3Boilerpro_3 Member Posts: 1,231
And got some very interesting data. The water temps are low, I believe, as the thermometers are on the outside pipe, but under the insulation and well below the boiler thermometer and the aquastat setting. The exhaust temp was taken by suspending the complete thermometer in the exhaust in a vertical section of pipe just outside the exterior wall, so it should be quite accurate.

Boiler supply: 136F
Boiler return: 123F
Exhaust: 113F
Outdoor: 8F
Boiler and venting system ambient indoor: 48F

The secondary (recuperative)heat exchanger beyond the condensing aluminum block really appears to do the job.... exhaust temps well below return temps. I imagine the low indoor ambient temp is also helping some too.. there's alot of condensate coming back off the vent pipe into the recuperative heat exchanger sump.



  • MikeB34MikeB34 Member Posts: 155

    How do you like the Quantum? I've been eying it.

  • Boilerpro_3Boilerpro_3 Member Posts: 1,231
    Just getting used to it

    My unit is an older model, so some changes may have been made since it was built. Looks like it will defintely need regular and thorough maintenance,just like less efficient condensing boilers, but it looks like you are getting more btu for your fuel dollar than condensors, especially when looking at that exhaust temp.
    I also wish the boiler manufacturers would stop trying to make thier equipment look like refrigerators... things like the relief valve, boiler drain, pump, etc are inside the cover and not necessarily in a good location. Also the factory aquastat has only a 10 F differential, which causes the boiler to short cycle in many situations, so I have already swapped it out with an adjustable unit set to about 22 F differential. The about one minute cycles are now around 6 minutes when the boiler does eventually get up to its limit. I have standing cast iron radiation, resized for my current heatings load at 150 average temp, with all modern piping, so the boiler doesn't hit the limit except when recovering from setback or in really cold weather. It also is a bit big for my heating load, output is rated at 95,000 but my peak load is 52,000.
    It's probably is a real good choice for commercial application, since it doesn't have it's own onboard reset controls. It would probably work out quite slick in a staged application where its the first boiler stage controlled by a tekmar staging and reset control. I already have heating plant replacement in a big home where I am going to recommend this or the Q-90.
    Not sure about the ignitor yet, as the Q-90's appear to have shorter than normal ignitor life. Also, on the one Q-90 I have installed I found the bolts holding the clean out plate were loose when I checked it about a year after installation. I understand this plate is gone on the new models.
    Not really sure why so many boiler manufacturers have adopted such an ureliable ignition setup from the unreliable forced air industry. I imagine direct spark would improve reliability.

    Only have had it going a few weeks, so time will tell some more!

  • MikeB34MikeB34 Member Posts: 155

    Thanks for the input.

    I looked into the q90 (not the leap). I like the look of it. for a condensing boiler, it is pretty basic looking. I like simple...less to go wrong.

  • Boilerpro_3Boilerpro_3 Member Posts: 1,231
    I agree

    Keep it simple, elegant, and efficient.

This discussion has been closed.


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