Keeping the hot tub full

Irene and I live in a place with a moderately cold climate. The Kootenays can have a few days in the winter with temperatures around -15 or so, although not commonly. It definitely gets cold enough that freezing is a concern.

Freezing is especially a problem when you have a giant outdoor tub filled with water that needs to be re-filled periodically, regardless of the outside temperature. How do you do that? Buckets aren’t a good option: a two or three inch top-up could require 50 or 100 gallons, which is quite a bit of carrying heavy buckets of water around. This is especially true in a house full of cats trying variously to escape and/or trip you up.

As is my normal behaviour, I resorted to technology for a solution.

Heated hose

My ‘fix’ for the spa refill problem: a freeze-detecting heated hose.

The hose is suitable for drinking water, has sensors at both ends for the cold (more on that later), and is generally speaking a fairly heavy duty piece of kit. I got the 50 foot long variety- longer than I needed by a good 20′, but I prefer to have some flexibility.

The basic idea with the hose is that you leave it connected to your outside water outlet and plug it in. You should have a proper Canadian-spec outside water valve i.e.: one that can handle a bit of freezing. I do recommend leaving the hose end open (no valve/shutoff, water flow turned off) so that there is room for ice expansion. As long as the hose is plugged in and the sensors working, the hose will keep itself and any contents above freezing.

Don’t forget to check the GFCI breaker…

Everything should have worked perfectly with the new heated / anti-freezing hose. And it would have, except we somehow hit the test button on the GFCI (ground fault circuit interrupter) outlet while plugging it in, turning off the power to the hose. The hose even has a little light to tell you it is has power, but apparently said light is almost impossible to discern in sunlight.

So the heated hose I so carefully selected didn’t do any good at all. It froze because there was no power running through it. I only discovered this disappointing news when it came time to refill the hot tub for the second time this winter: the hose’s frozen state left me unable to fill the hot tub until the problem was corrected.

My solution to the frozen hose and outlet was kind of stupid, although it all worked out. I forgot a few basic things about the hose itself when I put the tub end into the hot tub while I worked on thawing out the outdoor hose connector. The hose has temperature sensors at both ends and I’m pretty sure that one end being at about 40 degrees C would prevent it from coming on. Oops.

I was smart enough to focus my attention on unfreezing the house-connected pipe. Although technically ‘freeze protected’, it isn’t great to have water in an enclosed space (the pipe) in a frozen state. So I used the old hair dryer trick, then finally found our little industrial grade heater and hooked that up. I also eventually realized how stupid it was to have the tub end of the hose with its sensor dangling in the tub water. Better late than never, I suppose.

I got it all thawed out overnight: no problems. I finished filling the hot tub this morning. Some real-world education was received, and the spa hose returned to its proper duty of sitting patiently waiting for the next month or two before it is needed again..