Live Steam

Okay, that water heater thing is getting scary.

I was doing some yard work around noon, sunny day in the mid-nineties, when I saw that the water heater was dripping off the powershed roof again. Shouldn’t have been, the pressure to it has been turned off for about a full day and I bled the pressure when I turned it off.

I opened the faucet, and…


…well, okay. That doesn’t show up so well but it’d be more than your hand is worth to stick it under that faucet because after blowing out half a gallon of hot water it started venting steam at impressive pressure for just inflating a long garden hose.

The water in the bucket wasn’t record hot, but fairly hot.


Pity I already baked bread and washed dishes. 🙂

My plan was to start simple and improve/revise in increments but I’m starting to think my current design is too simple to work. Water lying static inside black hose in the summer sun just keeps getting hotter and hotter until something fails.

About Joel

You shouldn't ask these questions of a paranoid recluse, you know.
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12 Responses to Live Steam

  1. Ben says:

    Well, you always knew that this wasn’t likely to be your final design.

    If you are getting live steam, then the hose temperature is exceeding 212 degrees. With both the inlet ant outlet valves shut, you are bound to raise steam pressure! (If the inlet valve were open as usual, then pressure would be able to relieve itself in the direction of the storage tank.). I would try some shading on the box, and do it quickly.

    The ideal design would have a scrounged hot water tank and a circulation pump.

  2. jabrwok says:

    Not to beat a dead horse, but it’s starting to look like a solar distillation arrangement might actually be feasible.

  3. Malatrope says:

    I did tell you. You can bake pizzas in an uninsulated box with a glass cover.

    Ben has it right: to do this, you need copper pipe (rather one long coil, and any joints must be flare or compression (because your solder will melt, unless you use silver solder), a holding tank, a recirculating pump, a blow-off valve (from any hardware store, mandated on residential hot water heaters by code, to prevent steam explosions). Tee the loop into your regular water supply.

    The recirculating pump should be solar powered with no on/off switch, so that when the sun shines the pump runs. Use a dedicated 200W solar panel with no charger, directly wired to a 12V pump.

    Steam explosions are dramatic, and dangerous as hell. Do NOT seal in the pressure the steam will generate! And don’t try to control it by adjusting the shade on a simple system like you have, it will bite you in the ass (sorry I suggested it yesterday).

  4. Joel says:

    If you are getting live steam, then the hose temperature is exceeding 212 degrees.

    At this altitude probably not that much. Maybe just under 200.

  5. Malatrope says:

    Here, watch this Mythbusters episode:

  6. Mark Matis says:

    200 is STILL far hotter than your body can tolerate without permanent damage!!!

  7. Could you not have some sort of vertical pipe to act as a stack to allow pressure to vent?

  8. Anonymous says:

    Not sure how current this site is, but there is a lot of useful DIY info. Build It Solar: Solar Hot Water.

    Most folks add a solar driven pump, and heat a large tank. Life 500 gallons large. Not sure they have them on that site, but you can build such a tank out of wood and pond liner. Most of the people live in northern climes so there is a lot about drain-back. to prevent freezing.

    But yeah, a closed garden hose, lying in the sun will burst, given enough sunlight.

  9. Robert says:

    I foresee Joel luxuriating in a hot tub in midwinter after getting the bugs worked out. Well, I don’t wanna SEE it, but you know what I mean.

    Seriously, Joel, Mr. Sun works for almost free- put ‘im to work!

  10. Stefan says:

    All this talk of pumps and valves…the man needs cheap, passive, reliable.
    Not electric, he is already budgeting, and Murphy visits often.
    No boutique bio-vegan sustainable soy-latte manbun neo-hippie virtue-ware.
    No same-morning access to a well stocked plumbing & hardware supply chain.
    He may as well be on the moon, or 400 miles northwest of Fiji on some less-radioactive atoll.

    The man needs…..a thermosiphon:

    https://en.wikipedia.org/wiki/Thermosiphon

    Perhaps even a heat exchanger with a closed captive circuit and an open on-demand circuit. And he likely already has everything he needs, and the rest can be scrounged.

  11. Alan Wood says:

    And thermosiphon solar water heaters are already a well established technology just look up Passive solar water heater.

  12. B says:

    Thermosiphon needs the tank higher than the heater box.

    Best bet is a vacuum breaker at the top of the box , the box containing black painted copper, (or black poly tubing also works) and a valve to supply water to the heater.

    Alternatively, as suggested, a small 20 watt (ish) solar powered pump to pump the water through the system to a storage tank…but then you need some sort of pressure relief for safety.

    Probably the best bet is to get the heater box off the roof, and place it on the ground alongside a storage tank…and the solar panel for the pump.

To the stake with the heretic!