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What's the best way

of adding a corrosion inhibitor or glycol to a hydronic system?I used to have a long, brass hand pump that was expensive and worked OK, but it's disappeared. 
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab


  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    Get one

    of those hand pump garden sprayers and make up a hose connection.

    Works great.

  • hot_rod
    hot_rod Member Posts: 21,793
    small amounts?

    around 1 gallon or so, that Silver King hand pump works great.

    A garden sprayers with a hose adapter, is another simple, inexpensive option.

    I have a large expansion tank with a Webstone, and a Caleffi Autofill valve attached. Pump it up to 80 psi or so and carry 4 gallons to the jobsite, under pressure.

    Zuwa makes a top quality drill motor type pump, it will pump around 80 psi, a few gpm depending on your drill rpm..

    Larger quantities 10 gallons or more, a pump cart is a good option.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • M Lane
    M Lane Member Posts: 123
    Transfer pump

    Worth the investment. Mine is Liberty. They speed up draining water heaters, and you can use it to flush out a tankless water heater.
  • billtwocase
    billtwocase Member Posts: 2,385
    Wayne pumps

    I found the to be the best. Remove a gallon, mix it together in a 5 gallon bucket, and pump it back in
  • Thanks, everyone!

    Great suggestions.  Mr. Lane's suggestion of the Liberty transfer pump caught my attention - I like fast - and I ordered one.  I also like the idea of emptying a water heater in 10 minutes.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • M Lane
    M Lane Member Posts: 123
    Important note

    Don't let it freeze with straight water in the back of your truck. Remember that we use a 50% glycol mixture for outdoors radiant, not 30% like we usually put inside. so only feel safe keeping the remnant fluid in if you are working on snowmelt.
  • icesailor
    icesailor Member Posts: 7,265
    Air compressors:

    A air compressor will do it in even less time. Once I started using my portable hot dog tank air compressor for draining houses, my cast iron Wayne pumps stopped working from lack of use. If you try to suck water from the bottom drain of a water heater and the stem packing leaks, you suck air and don't get a good vacuum. With compressed air, you don't have that problem. As I became more and more aware of all the multiple uses of air compressors, it became the one tool I never took out of the truck.

    If I had a leak in a pipe, blow it out with air. The whole house. No running drain back. Solder the leak with no water. When done, charge up the system with air to see if it is leaking. If not, turn on the service valve and screw.

    You have no idea how much easier it is with air until you start doing it.