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Bosch Greenstar help

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Westie_2
Westie_2 Member Posts: 12
in THE MAIN WALL
I've installed a greenstar 100 combi in my house. It seems nice. If I could get it to heat to desired temp and shut pump off when satisfied. I'm running two zones with a zone valves and zone control. A grundfos alpha pumps and outdoor temp only. Can't get outlet water temp above 165. Boiler Temps are 184. Did heat loss at design temp of 180. output temperature drops as low as 119 before fireing boiler outside temp is in the 20's. After all zones are satisfied alpha is showing power and 0 gpm I've searched for info on operation. Need a little help fine tuning it. Looked a t bosch classes only one this to year and it's full.

Thanks steve

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  • R Mannino
    R Mannino Member Posts: 440
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    It's probably a programming issue, bust out the manual. First try changing the mode from economy to comfort with the Eco button and turn up the heating dial to max.
    Robert O'Brien
  • Westie_2
    Westie_2 Member Posts: 12
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    It's set on comfort and nob on boiler is all the way up. Went thru commissioning steps.
  • Ironman
    Ironman Member Posts: 7,377
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    Can you post some pics of the boiler, its near piping, pumps and controls?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Westie_2
    Westie_2 Member Posts: 12
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    Here is a couple before I finished.
  • kcopp
    kcopp Member Posts: 4,435
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    is the fw200 control installed?
  • Westie_2
    Westie_2 Member Posts: 12
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    Yes on the boiler
  • Ironman
    Ironman Member Posts: 7,377
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    Your pics only show one zone connected with 3/4" pipe. That translates to about 40k btu's available.

    I can't tell what your piping looks like below the boiler, photo is too dark.

    Is the system sensor installed right after the closely spaced Tees?

    The FW200 is an intelligent control that learns the heat requirements of the structure. If everything is not setup correctly, then it won't respond correctly.

    What setting is the Alpha on?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • R Mannino
    R Mannino Member Posts: 440
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    Is the outdoor sensor installed? If it is what is the ambient outdoor temperature?
  • kcopp
    kcopp Member Posts: 4,435
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    Sounds like your house is heating. The alpha is usually always on. This may help...
    https://www.youtube.com/watch?v=EMboIQYGVvg
  • Westie_2
    Westie_2 Member Posts: 12
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    The house is heating. Just won't reach desired temp. Alpha is set to adept. 1 gpm 11 watts. Out door control is there. Outside temp at time was 26 degrees. Temp sensor is installed. Bosh rep set up fl200 said it looked good. All piping was correct. He's on vacation. Im trying to learn. It's in my house. Second zone has been installed. Total load is below 30 btu. 3rd zone will bring it to 40 k. He'll be around tomorrow. He lives close mabey he can stop by. I'll keep posting. If it wasn't going to be in the single digets this week I'd start pushing buttons. I sapose worst comes to worst just factory reset and commission it again.
  • SWEI
    SWEI Member Posts: 7,356
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    Westie said:

    Total load is below 30 k btu. 3rd zone will bring it to 40 k.

    With a minimum firing rate of 34.6...
  • Westie_2
    Westie_2 Member Posts: 12
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    SweI. Is that a question or a statement?
  • SWEI
    SWEI Member Posts: 7,356
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    An observation. Nothing much to be done about it now other than adding a buffer tank of some sort.
  • Westie_2
    Westie_2 Member Posts: 12
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    I knew that. I thought that just effecency. I'm getting 89 to 91 % and condensing. On one zone both zomessage I'm getting 95.% I've heard about buffer tanks for but I'll have to look at that some more.
  • Westie_2
    Westie_2 Member Posts: 12
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    The boiler is doing its job. 187 at boiler and 168 feed. The adept feature on the alpha is seeing dead head when zones are closed. So when it calls It's only pumping 0 to 1 gpm at 11 watts. I'm gonna see of I can get the taco zvc403 to run the pump and and learn a different curve. Even playing with the button on the pump I can't get it to flow 2 gpm. I may try a 007.
  • icesailor
    icesailor Member Posts: 7,265
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    Does the article by Siggy in the November issue of P&M have any application to this discussion?

    "Hydraulic Equilibrium".

    (Nature doesn't care-----But YOU should.)
  • Westie_2
    Westie_2 Member Posts: 12
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    (As is true with thermal equilibrium, the operating condition at which hydraulic equilibrium is established isn’t necessarily one that will deliver the proper rate of heat flow or allow the system to operate efficiently or reliably. It’s just where the rates of energy input and output are balanced. Our task as designers is to ensure each system we design can deliver comfort, efficiency and reliability while operating under these naturally balanced conditions.)
    My brain hurts. I'm going to bed.

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