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Garage hydronic heater

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champ12
champ12 Member Posts: 4
in Radiant Heating

I am looking at adding a zone to my current boiler for my garage. I'm looking at buying or building my own hydronic unit heater. How can I add another zone to my current boiler? I understand I will need another pump is there an easy way to add to my current set up or do I need to do some major plumbing work to make this work.

4673.png

Comments

  • mattmia2
    mattmia2 Member Posts: 16,117

    you would have to repipe the boiler to manifold off to 2 circulators or 2 zone valves, might as well put the circulator on the outlet and after the expansion tank while you're at it. You have to change most of the near boiler piping but there isn't much piping there so it is a relatively small project compared to running the piping out to the unit heater. hydronic unit heaters are fairly pricey but available from several manufacturers.

  • hot_rod
    hot_rod Member Posts: 27,116

    Is it just a single zone now? Or are there zone valves above the boiler?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2
  • champ12
    champ12 Member Posts: 4

    It is currently 1 zone. There is a ball valve above the boiler that runs to underfloor heat between the joist in 1 bedroom. The rest of the house is ran in series to all the baseboard radiators. The 2nd ball valve is behind the exhaust vent.

    4674.png
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,800
    edited January 29

    I see a Filtrol® valve with no Filtrol® tank, and what appears to be a loop of some type of heat added at some point after the original system was installed using orange PEX with about 3 feet of foam pipe insulation  on the tee near the supply and the tee near the return.  I do not see an expansion tank in the photograph. It might be hidden behind the vent connector pipe (smoke pipe) This near boiler piping needs an upgrade and this additional garage zone is the time to do it.  

    Screenshot 2026-01-28 at 8.51.17 PM.png

    If the Filtrol expansion tank was still operating properly, the vent connector would not be covering the expansion tank completely. (the blue tank is where it would be)

    There is also a Taco Air Scoop hidden behind the B&G Flow Control Valve. No need for the "B&G Flow control valve" if it is only one zone. This system has been worked on by several people over the years. Time to make it right!

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,800

    Here is an idea of what I might do in your situation:

    Screenshot 2026-01-28 at 10.32.45 PM.png

    This uses a separate circulator pump for the garage zone. I also added a mixing valve for the radiant floor zone which requires a separate circulator pump to work the mixing valve. I can't see that putting 160°+ water temperature in the radiant floor loop as a good thing for the floor covering or your bare feet

    Another idea if the existing pump can handle it:

    Screenshot 2026-01-28 at 10.21.17 PM.png

    This uses zone valves and the existing pump. No need for flo-check since each zone valve uses the same circulator. You will need to verify flow rates to see if the existing pump can handle the extra load.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

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