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Loch- 55 Update-

ced48ced48 Member Posts: 383
I just finished installing a Lochinvar WH 55. I piped it direct, because it seemed foolish on such a small system to go prim/sec. I followed a Triangle Tube design. So far, I think I made the right choice, for sure. But there is one thing I want to let anybody doing a similar install to know, forget trying to use a delta t pump. All it seems to do is confuse the whole modulation process. I think the two adjustments, pump speed and boiler firing rate, just chase each other around, until the confusion shuts the boiler down on high limit being satisfied, even though its not even close to that temperature. I don't know how a pump controlled directly by the boiler's computer would work, and I don't plan on spending $400 to find out. My hunch is, might work better, but I think it is totally unnecessary. The modulation process takes care of what I am looking for, delta t seems to be not so critical to good performance.


  • SWEISWEI Member Posts: 7,356
    Boiler control over pump speed

    is really the right answer.  Lochinvar at least provides an output for that -- too bad none of the residential-sized ECM circs allow for external control.

    A 10ºF ∆T will produce fine comfort, it just doesn't do much for boiler efficiency.
  • ced48ced48 Member Posts: 383
    But Won't the Boiler-

    work less with the tighter delta T? I could buy a 007 with low voltage control, but I question what the real savings would be, never mind the complications it would introduce. I am running the indirect with a delta T of 13, running a pump at slower speeds than the indirect maker suggests, so I really don't want to go any slower. The little 20 gallon tank recovers in less than 10 minutes, so I am quite pleased.
  • SWEISWEI Member Posts: 7,356
    Bouler aux output

    should play nice with the rest of its controls.  Rinnai uses a 35ºF ∆T target in theirs.  I believe Viessmann does this in some of their EU offerings.

    I wonder about post-purge and other safety routines in the boiler controls "fighting" with the smart pump.  The jobs where I've done this have had both the boilers and the pumps under 0-10V external control.
  • SWEISWEI Member Posts: 7,356
    Increased ∆T

    means lower returning water temps which produces more condensation.  This requires increased supply temps (to create the same average temp across emitters) but it's the return temp that matters for efficiency.
  • ced48ced48 Member Posts: 383

    That's what I am concerned about-What speed will the boiler tell the pump to run at on startup? All of the cold water has to be put thru the system, running a negative delta T for a brief period. The Bumblebee, in delta T mode, ran full output for the first 3 mins, letting the system even out- I don't think the boiler controlled pump will be able to do this.

    Right know, with the outside temps in the low thirty's at night, and using the outdoor setback, I am getting good condensing, but I know I will loose a lot this as it turns colder, but I still fell like I am way ahead of my old system. Running at 88%, or 95%, I still am saving.

    I also feel that running baseboard heat at temperatures well below design, make for an uncomfortable living space. I know my system is a compromise, but I think it will work for me.
  • EastmanEastman Member Posts: 783

    What settings on the loch did you try?

    What delta were you trying to get with the bee?
  • ced48ced48 Member Posts: 383
    Delta-T of 20

    It would either keep the delta-t under 20, or let it get way beyond, maybe close to 35. What are the other settings you are interested in? The dam Bee's hum kept me awake again last night. It's running a speed SP2, kinda the speed of a 005. Seems like a good speed, but I'm going to replace it with a conventional circulator.

    I have the space heating temperature settings set between 120 degrees and 180, and the outdoor reset set from 55 degrees, down to 5 degrees. I really don"t have the extra baseboard to try much lower temps, but I will keep playing.
  • ced48ced48 Member Posts: 383
    ∆T Symbol-

    After all my posts, I finally found out how to type the ∆T symbol, on a Mac anyway, it's option j.
  • ced48ced48 Member Posts: 383
    Here's a Photo-

    Here's the Loch in his 22" x34" closet
  • SWEISWEI Member Posts: 7,356

    Where does the little drum-shaped condensate neutralizer come from?

    Any chance the buzzing is related to the 90º elbow right after the 'Bee?

  • EastmanEastman Member Posts: 783
    Are you using any of the ramp settings

    for the the loch?
  • ced48ced48 Member Posts: 383
    I Made the Neutralizer -

    from a 11/2" drum trap. No the noise is not turbulence, it's an electrical buzz, confirmed byTaco. There is about 5" of straight run before the 90 begins to turn, not the way I would go if I had more room, but it seems to be causing no issues. The 10 pipe rule is for upstream, downstream is not as critical.

    Right know, I have ramp 6, the last, set for 75 percent for space heating, 100 percent for DHW. I will mess with these as the weather gets colder, and gives me better test conditions.
  • ced48ced48 Member Posts: 383
    All the Other Ramp

    settings are in the default settings-
  • SWEISWEI Member Posts: 7,356
    Drum Trap

    I thought that looked familiar.
This discussion has been closed.


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