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Advice Needed -- WM97+110 with Staple-up Radiant and 2-Zone Baseboard

MindIron Member Posts: 2
edited October 2018 in THE MAIN WALL
Just had a WM97+110 installed with indirect DHW. Slant fin baseboard (not yet installed) to the 2nd and 3rd floors---two zone valves above Taco circulator at the left of the attached picture. 1st floor will be staple-up radiant in two zones with independent, 3-speed Groundfos circulators, with a total of 8 circuits of 1/2" pex (only 5 circuits are installed now, and are pictured in the attached picture).

Couple screwy things that the installer said that I'd like to ask about to start. Going to have some general need for advice with the tweaking of the system going forward, but the couple quick questions are:

1. We should definitely have the outdoor reset installed, right? When the installer was booting up the system, I asked where he placed the sensor outside, and he said that they are more trouble than they're worth. Doesn't that knock-out one of the most energy-saving features of the boiler?
2. Also, the system type is now configured to Fin Tube baseboard, with the supply temp at 180. That water then hits a mixing valve prior to hitting the radiant circulators. Should's we set that to one of the lower settings so that, when coupled with the outdoor reset, the boiler stands some chance of condensing?
3. Can I change the speed of the radiant circulators (to slow them down from the high speed that their set at now) independent of the circulator built into the boiler, which is also set to high? Or do I have to set them to the same speeds? I'd like to slow them down so that some more heat gets dumped to the floor. Right now, the returning water is anywhere from 1-3 degrees cooler than the supply---according to the internal numbers from the boiler.
4. How can the return temperature to the boiler be 1-3 degrees cooler than the supply when all the water that's being circulated now is being mixed down to ~125 for the radiant? (The baseboard circuits are not being fed now.) I can't figure this out. Is the internal sensor in the boiler bad?
5. Any advice for pipe clamp thermometers? I have some coming on Monday to hopefully place and get some pipe temperatures, at least. (https://www.supplyhouse.com/Viega-15055-Strap-on-Temperature-Gauge-Set) I had some other ones on briefly (https://www.supplyhouse.com/Winters-Instruments-TCT167-2-5-Aluminum-Clamp-On-Thermometer-30F-to-250F) but I don't think I was getting anything like accurate readings.

Sorry for the word vomit. And thanks, in advance, for any advice.


  • DZoro
    DZoro Member Posts: 1,048
    Strange piping, is there check valves in all 3 pumps? What temperature did he design for the baseboard system? Low temp I hope. I get confused where the water is supposed to go, I can't imagine how the water feels about which way to turn. ODR to me is a must, but in this case is questionable but I would still install it. It largely depends on the design of your baseboards. I'm thinking your mixing valve maybe having a hard time getting the cold water it is looking for.

    I'm sure others will chime in and give their thoughts also.
  • MindIron
    MindIron Member Posts: 2
    Thanks for the reply, and the input.

    Both of the Grundfos's are UPS15-58FC and have check valves. Not sure about the Taco, which was supplied by the HVAC company.

    To take it back a step, my lady and I installed all the radiant (as well as the domestic water pex) all the way back to the manifold. We purchased various components from a company called Radiantec, and then purchased a bunch of others on our own.

    We contracted with an HVAC company for the install of the boiler and DHW indirect (as well as ductless mini-split) install.

    My lady's brother is a master plumber, so he piped the majority of house, which we gutted down to the studs. It was sort of up-in-the-air as to who would be doing the piping tieing in the pex to the boiler. In the end, it was the guy from the HVAC company.

    At this point, I'm just trying to make sure that this mod/con boiler that we paid a pretty penny for is set up so that it can realize it's potential.

    And sadly, despite the manual clocking in at something like 144 pages, the WM guidance in terms of actual setup is a bit lacking ...
  • hot_rod
    hot_rod Member Posts: 22,254
    It's actually a very well detailed manual, as installation manuals go these days. The installers needs to understand what primary secondary piping is and how it works. Do they?

    How is the primary secondary valve inside set, pumps sized via their formula and example?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream