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.

Frozen pex infloor

bfcnb Member Posts: 1
Hello all. I recently purchased a home with a garage. The garage has 1/2” pex in the floor for heating which has a small leak in each zone(water was left in last winter). I thought I’d try something and sucked some pull string threw them. Before I buy this do you think it will work and I don’t expect full performance. If it’s a waste of time I won’t purchase the tubing. I was thinking on pulling and pushing in 3/16” poly or pex inside of the 1/2”. I had a 50’ roll and was able to push it in. I’m thinking with some lube and the pull string I can get this pulled through(36X36 4 loops) Do you think it would perform? I run a outside wood boiler which is to big for the house and i’m Not afraid to throw a lot of wood at it.


  • hot_rod
    hot_rod Member Posts: 18,281
    Any idea how long the loops are? Typically 1/2 pex is 250- 300 foot loops. If it has a lot of bends or 180 bends I doubt you will force a tube that distance? The 50' may have been in just a straight section.

    Might consider using new pex and put in radiant ceilings.

    Or a hydronic unit heater
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    HVACNUT Member Posts: 4,875
    I know it's a little unethical but you can try pumping boiler seal through the system.

    The way it is now theres no love lost if it doesn't work.

    I haven't used it in years but if I remember right, the boiler and zone(s) must run X amount of time at Y degrees. I guess I don't remember right.

    With radiant I would run it for 24 hours and,
    Disclaimer: Installation pros can better clarify.

    Depending on the floor, depth of the pex, barriers, I think you should open the mixing valve in increments to whatever temperature is acceptable for the floor and still supply a higher temperature until the sealer has cured. Then throttle the valve back down.

    Check the pressure, close the feed valve and keep an eye on it.

    If it works, it only costed a few bucks for the sealer. You've got the funnel.
  • GroundUp
    GroundUp Member Posts: 1,496
    I really think your dollars would be better invested in another heat source. Even if you were able to get the tubing snaked through, which I seriously doubt, assuming the previous owner had been running atmospheric OWB water through the floor and it's most likely half plugged up with crap, your BTU output through a 300ft loop of 3/16" might only be 1000-2000 which is not likely to even keep the place above freezing on the cold days. Hanging unit heaters pair great with OWB and many people prefer them over radiant floors due to the quick reaction time. Otherwise a radiant wall or ceiling may be an option as Hot Rod mentioned.

    Side note though, how bad are these leaks? They CAN be repaired, possibly at a much lesser headache than the 3/16" tubing method if there aren't multiple bursts in each line.
  • Ironman
    Ironman Member Posts: 7,088
    Even if you could pull the 3/16 tubing through the 1/2" (very doubtful), you would have very poor heat transfer from it to the 1/2". As mentioned, the flow rate would also be so low as to be of little use.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • hot_rod
    hot_rod Member Posts: 18,281
    the sealers can work with pinholes, but if the tubing is split in multiple loops, typical of freeze up, time to think about plan B.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream