Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Vitodens 100w-b1ka

leftandfront
leftandfront Member Posts: 9
in Radiant Heating
I have recently bought a cabin with new B1KA. One central heating loop. and DHW. It is having some trouble maintaining room temperature on colder days. Have been reading lots on here as well as manual. I have a couple questions. Should the boiler be set in CONFI to 100% (DHW Boost)? If the system pump is running at 4GPM is it neccessary to adjust the internal pump? Thanks in advance.

Comments

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,243
    What kind of heating do you have? Radiant? Radiators? Hydroair?

    Do you have an outdoor sensor mounted on the north side of the cabin?

    You may need to adjust your heating curve. I wouldn’t play around with the pump speed just yet. 
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    Mad Dog_2
  • leftandfront
    leftandfront Member Posts: 9
    Fin tube baaeboards. Outdoor sensor on North side. Heating curve @ 2.4 I believe.
  • Paul Pollets
    Paul Pollets Member Posts: 3,664
    A well designed system using fin tube should use a 2.0 curve. The curve adjustment will raise or lower the heating output of the baseboard. If a curve of 2.4 is required, the footage of baseboard installed may have been originally sized for a 180 degree water temperature, instead of 140. When designed for 140, the boiler will be in condensing mode most of the time. It's not uncommon to have to raise the heating curve when extremely cold weather prevails.
    Mad Dog_2GGross
  • leftandfront
    leftandfront Member Posts: 9
    I agree with everything your saying about the curve. Looking at adding more ft of BB in summer. Just wondering if the internal pump should be set slower. Has primary secondary with close tees.  -28 C here right now. Has trouble getting indoor temp to 21 C. 
    Mad Dog_2
  • john123
    john123 Member Posts: 83
    Would it help to do a rough Heat Loss calculation. You only need type and sq ft area of windows, walls, doors, ceiling (insulation) and perhaps floor; and design temp (usual record lowest temp in past years) {-28C itself is quite cold} and perhaps not necessary for a rough calculation --but to fine tune it, average wind direction and strength. You will also need the the "R" numbers but if you can get the mesurements, You are almost there. Maybe 100 K BTU is not enough?
    As well --what is the "set" point on the boiler ( you can set it yourself) ---like the maximum boiler water temp. I am going through the same issue as you so I will be interested in what the experts have to say.
    Mad Dog_2
  • leftandfront
    leftandfront Member Posts: 9
    Set point adjusted to 70. 700 sq feet. 9.5 ceiling.  Temp runs at 180F. Could possibly be air. Has taco 4900 air scoop.  Have bled BB. Boiler BTU should be well sufficient. Listening to system pump sounds like there may be air.  Air scoop screw is open. pressure #13. Air scoop possibly stuck.  Not sure. 
    Mad Dog_2
  • john123
    john123 Member Posts: 83
    Well it certainly seems that the boiler should be big enough. Just the same it should be helpful to see how many BTU's you need (and how oversized the boiler is, if such is the case) and whether the BB rads are sized so that they can actually lose enough heat to keep you comfy. Has the boiler ever operated in -26C or lower and satisfied the thermostat?
    The other thing that I found helpful is a laser beam temp gauge (gun) to check the supply and return temp (so-called "delta T") and the temp of my cast iron rads. If your boiler water is (says it is) 180F---- what is real supply temp in the pipes and the temp in the BB rads (emitters)?
    Mad Dog_2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,625
    Unless you have zero insulation and a fireplace flue wide open you should have plenty of boiler.  Did u say air scoop?
    Any pics of boiler and piping?  I'm a Spirovent Guy or Caleffi...High quality air eliminators make SUCH a difference.   Mad Dog. 
    Consulting by Mad Dog & Matt Jr.
  • leftandfront
    leftandfront Member Posts: 9
    Hope this picture is good.  Temp on fins on baseboard ~100F. Does that seem right?  
  • leftandfront
    leftandfront Member Posts: 9
    The Alpha 2 circ pump is set on speed 3 and sounds like it is cavitating (small pebble sound). Speed 2 it goes silent. 
  • neilc
    neilc Member Posts: 2,912
    did I miss it, where's that circ?
    the one in the boiler?
    you need a circ on the pex loop to drive hot water out to the system
    known to beat dead horses
  • leftandfront
    leftandfront Member Posts: 9
    Yeah it's in the top left of the picture where you see cord. Hard to get in pic. 
  • Paul Pollets
    Paul Pollets Member Posts: 3,664
    Try setting the pump to "Auto"
  • neilc
    neilc Member Posts: 2,912
    that's hard to see, any chance you pull the cord aside and get a shot of the volute on the circ case,
    or, which way is it pumping?
    and is that motor horizontal or vertical ?
    can you tell if that circ is running? amp draw?

    what does the boiler say it's putting out for temperature?
    and what do you have for boiler pressure?
    known to beat dead horses
  • leftandfront
    leftandfront Member Posts: 9
    edited February 2023
    Pump mounted horizontal. Circ pump is running for sure. Temp ~180. Pressure ~14. Pumping away  Just turned circ pump to speed 2. Pump runs quiet. Will see if there is any change. 
  • neilc
    neilc Member Posts: 2,912
    how are you measuring the 100 at the fintube?
    can you touch and hold the pipe there?
    I would expect 180, TOO HOT TO TOUCH, at the fintube
    known to beat dead horses
  • leftandfront
    leftandfront Member Posts: 9
    Laser temp reader. On fins. 
  • neilc
    neilc Member Posts: 2,912
    lasers are funny,
    they don't like shiny things,
    sometimes measure slightly off from where you see the dot,
    if you reach to the pipe, is it too hot to touch ?

    are you cold in the space? guessing yes since you're here asking , , does the thermostat satisfy to setpoint?
    known to beat dead horses
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,243
    With everything you've said and at -28C, I agree with you that you don't have enough baseboard.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • hot_rod
    hot_rod Member Posts: 23,818
    how many feet of fin tube do you have. The feet of actual fin X 550 will get you a ballpark of what can be transfered into the space.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Paul Pollets
    Paul Pollets Member Posts: 3,664
    Earlier models of the V100 hit a high limit of 167. I'll go with not enough BB

Categories