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Replacing Baseboard Heat with Toe Kick

I am looking to replace a section of baseboard heat with a toe kick as I am installing cabinets. I'm trying to determine the correct way to only drain the zone that I will be working on (zone 1) and then filing it up/removing air from the line after the toe kick is installed. I am attaching a few pictures of the boiler setup in my basement. Would someone be able to advise on how to best go about this please?

Any info would be much appreciated.



  • rick in Alaska
    rick in Alaska Member Posts: 1,420
    What you would need to do is turn the boiler power off for a few minutes to make sure the zone valves (the controls in the first picture that are on the pipes, and have wires coming out of them) are off. You can verify them being off by trying to pull on the little lever on them and see if you get resistance, after trying to move it about 1/3 of the way. Then close the ball valves in picture 2 (with the yellow handles). They will be closed when the handle is going sideways against the pipe. Next open the blue handle drain valve above the ball valve to get it to drain. I would put a drain hose on it and run it to a bucket.
    In order to get the line to drain, you are going to have to cut in the the pipe up top where you are going to put in the kickspace heater. When you are all done and want to purge out the air, just manually open the zone valve for zone one by pushing the lever all the way open ( this is hard and will put a dent in your finger). Then just let the water flow out of the drain hose you still have hooked up until no more air comes out. After it runs clear, then just put things back like they were and you should be good.
    All of this is assuming this run doesn't have a lot of baseboard on it already, in which case the pump might not be able to handle the extra restriction of the kickspace heater. Also, depending on the boiler output and the placement on the heating loop, the kickspace might not work right. They need, I believe, 130 degrees water flow before the internal fan switch turns the blower on.
  • celogan1985
    celogan1985 Member Posts: 5
    Thanks so much for this info, Rick. Much appreciated!
    HVACNUT Member Posts: 5,025
    Does a toe kick get piped in series, or is it a branch off the loop?
  • celogan1985
    celogan1985 Member Posts: 5
    @HVACNUT I'm not sure but my thought for mine was to do it in series since I am replacing existing baseboard and actually shortening the overall loop. If i was looking to heat a room that wasn't close to the existing series then I would do another loop and maybe another zone....all this is to say I could be completely wrong because Im definitely not a HVAC expert. just my thought process
  • hot_rod
    hot_rod Member Posts: 19,273
    Most kickspace heaters a 1/2" tube size, so if you have additional fin tube down stream, in series, you might pipe it as a bypass with a valve to regulate flow, allowing some to bypass
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • celogan1985
    celogan1985 Member Posts: 5
    thanks. i plan to use a pair of monoflow tees on the supply and return ends of the toe kick which I believe is similar to what you are saying, right? In terms of filling the zone/boiler back up, based on the pictures above and the process @rick in Alaska outlined, what do you recommend?
  • HomerJSmith
    HomerJSmith Member Posts: 2,143
    edited February 2022
    I have done this many times. How you do it depends upon where the supply water is coming from, above the floor or below the floor.

    If the supply is on top of the floor like a baseboard is removed, I do it this way. First, as hot_rod says the piping in the toe kick is 1/2" and presents a pressure loss in the 3/4" loop. So, I take a 3/4"X1/2"x1/2" copper tee and connect it to the 3/4" supply and than I run a 1/2" bypass to another 3/4"X1/2"X1/2" tee then to the 3/4" return to the boiler. I then connect the 1/2" side ports of the copper tees to the toe kick supply side and return side. You have to have a pressure differential to move water thru the toe kick. The tees and the 1/2" bypass gives you that pressure differential without interrupting the flow to downstream heat emitters.

    If the supply & return is under the floor and is accessible, I use Monoflo tees, sometimes one and sometimes two. You can use Monoflo tees on top of the floor too, but they are expensive and regular tees work just fine at a much cheaper cost.

    I don't use Chinese diverter tees.
  • celogan1985
    celogan1985 Member Posts: 5
    Thanks @HomerJSmith. I will be working with the lines under the floor since that is crawl space