Edit 7/29/2022: When all was said and done, I bought another copy of the one that just broke. I then modified it by drilling two small weep holes, like so:
I then mounted this horizontally (with the dial facing the sky). In theory, when this leaks — and it will — the weep holes will allow the water to drain without drowning the motor. Which — see below — is what killed the first one.
The original post follows.
A hose timer is a gizmo for turning water on and off on some pre-set schedule. You (typically) stick a couple of batteries in it, program it, place it between faucet and garden hose, and turn the faucet on. It will then operate a little valve to turn that water on and off according to your chosen schedule.
Until it breaks. Which it will. Which you probably won’t notice until your plants start withering. Unless you’re away on vacation, that is. In which case you’ll return to dead plants.
I just had yet another one die, after a little over one season of use. That’s probably the third or fourth one of those I’ve bought. None seems to last more than a couple of seasons. Judging from the comments on Amazon, that’s the norm.
Instead of viewing each device failure as some unique event, I have finally come to realize that this is one of those products where everything sold for home use is some variation on “a cheap piece of crap”. Regardless of price, name brand, or design, each lives out its brief existence over a one-to-two year span between hardware store shelf and landfill.
I am further handicapped because I use these with water barrels, and most hose timers won’t operate on that low a water pressure. I have to choose from an extremely limited subset of options, within that universe of crappy hose timers.
Anyway, I’m tired of chucking one of these in the trash every year or two. And yet, a hose timer is a really handy thing to have. Particularly now that I have an irrigation system for my garden that can, in theory, be used with my water barrels. I just need a way to turn that on for about six hours a day. Because, unless I automate that, I will undoubtedly forget to shut it off at some point.
So, as is my habit, I thought I’d take a deeper dive into the issue, to see if there are any better alternatives. Does there exist a durable hose timer suitable for use with a low-pressure rain barrel irrigation system. If not, is there anything I can do to prolong the life of the timer. (I already have the good sense to bring it indoors for the winter.)
Autopsy
This time, rather than just chucking the dead timer in the trash, I took it to pieces to try to figure out why it failed.
I guess it should come as no surprise that it failed due to water intrusion. As a rule, electronics and plumbing do not mix.
In particular, the casing on the little electric motor that opens and shuts the valve was thoroughly rusted. This suggests that the timer had been taking on water for some time.
At the time of death, there was quite a lot of water inside the case. I’m not sure whether the water was rainwater entering from outside the case, or water seeping around the valve mechanism inside the case. But given how it was mounted, and the waterproof lid, I’m betting this was leakage from around the valve mechanism inside the case.
What I am sure of, though, is that in trying to keep these waterproof, they build the case like a little bathtub. Thus insuring that if they leak, the water will stay right there in the case.
As an extra added bonus, for this valve, the manufacturer mounted the electric motor in the lowest portion of the case, if the timer is mounted either vertically or horizontally. So that, if the case takes on any significant amount of water, the design ensures that the motor ends up under water.
In summary, this was not a failure of the electronic controls, or of the mechanical drive components. This was a failure of the drive motor due to a combination of a non-draining case design coupled with imperfect waterproofing.
Basically, the device took on water until it drowned the motor.
Here’s how the device looked when new. It comes with a screw-on gasketed plastic cover that fits over the face. The Amazon writeup describes it as “waterproof”.
Source: Amazon.com
Here’s the exploded view of my defunct unit. To the left is the blue face plate, containing all the electronics. In the middle is a black plastic plate that holds the motor and a set of five reduction gears. In the case itself sits the valve, with the final reduction gear attached to the valve stem.
Well, there’s your problem, below. This is the same exploded view, with the pieces turned profile. As you can see, the motor housing is quite rusty.
Finally, here’s a view of the one-piece case bottom, where I have marked where the motor sits when the timer is completely assembled. If you mount the timer so that the face is horizontal, that guarantees that any water that gets into the body comes into contact with the motor. If you mount it vertically, with the direction of flow pointing down, it’s not much better,
Action items
For this most recent dead hose timer, I didn’t fry the electronics, or wear out the mechanical parts. I drowned the motor, most likely from water bypassing the seals around the valve.
I can’t be sure that this is the only way that these timers die. But assuming that death by drowning is a common failure mode, there are a few things I can do.
First, I appear to be stuck with using a cheap battery-powered timer. There are purely mechanical timers that operate like a wind-up kitchen timer. Those appear to be far more reliable, but those are only shut-off timers. You twist them by hand to turn the hose on, and they’ll turn the hose off after some interval. You can’t automatically water your garden with one of those, or have it water your plants while you are away.
Second, of the limited number of battery-operated timers that will work with a low-pressure (water barrel) system, all of them seem to be of the cheap-piece-of-crap variety. All suffer from a short lifespan. And, from what I can tell, all or almost all of them are built more-or-less along the same lines. Some have purely electronic controls now, instead of the physical-dial controls on this one. But that’s more-or-less irrelevant. The controls aren’t what failed. All of them appear to have a body that is some version of a one-piece plastic tub. So I suspect that all of them are subject to drowning the motor via water intrusion.
Third, do not mount these devices horizontally, with the dial flat. I’ve seen a handful of hose timer manufacturers that specifically say not to mount these horizontally. But not the manufacturer of this particular device.
That’s kind of a pain, because, by far the easiest way to set these, when attached to the bottom of a water barrel, is with the dial flat. But if you mount it vertically, with the direction-of-flow arrow pointing down, then any water intrusion should show up as a puddle inside the clear plastic cover. And with luck, I should be able to allow that to drain before it kills the valve.
Fourth, alternatively, mount it flat but drill some weep holes in the bottom of the case. Near as I can tell, with a screw-on gasketed lid on the case, the water intrusion was from the inside. And ultimately the problem is that the water had nowhere to go, within that sealed case. Maybe the smartest solution is just to add a two tiny weep holes so that the water has some place to go. Plausibly, you can use a magnet to identify where the motor is within the plastic housing of any of these valves. (You’d need one weep hole on either side of the water passage that runs down the middle of the bottom of the case.)
When all is said and done, probably my best strategy is to buy another one just like the one that broke. That way, I can plan exactly where the weep holes should go, because I know where everything is on the inside. And I can mount it in a convenient, face-horizontal orientation, where the gasketed screw-on lid should be able to keep any rain water out of the works.
I can’t be sure that water intrusion is the only failure mode on these valves. But it surely makes sense. And if that’s water intrusion from the inside, the only long-term solution is to give that water some place to go. So I think I’m going to give Yardeen another $20, then immediately void my warranty by drilling some tiny holes in the bottom of the case.
Practically speaking, there will be no way to tell whether that works or not. But if I can get the next one to last three seasons, I’ll declare victory.
Addendum: Why I probably can’t use a hose timer on my gravity-fed garden irrigation system.
Before my hose timer broke, I was using it to water a potted tree and a few other plants, using water from a rain barrel. The tree, in particular, has a lot of leaf area relative to the size of the pot, and needs daily watering during hot weather. It was a real plus to be able to set up automatic watering with the hose timer and water barrel.
But I now realize I won’t be able to insert one of these timers into my new garden irrigation system. The valve opening is simply too narrow. Squeezing enough water to feed the entire garden irrigation system, through that narrow valve opening, would require a rate of flow that is far higher than I can achieve with the low water pressure from a water barrel.
Here’s the math:
If I run all-half-inch-pipe, the water has to exit the barrel at a speed of about two inches per second. I’m sure the water barrels can push that much water through half-inch tubing. Why am I sure? It takes well under a minute to fill a 2-gallon watering can, from the rain barrel, through a garden hose. That’s a rate of at least 120 gallons an hour, or at least five times faster than what the garden irrigation system actually requires.
But if I try to squeeze the same amount of water through the narrow (8-mm-diameter) valve opening, the water would have to move at around 20 inches per second. I haven’t tested it empirically, but I don’t think it’s even remotely possible. Per the watering can example above, even when connected to 1/2″ hose, the water barrels don’t move water that fast. Friction and turbulence in that narrower opening mean that the water will move less rapidly, not more rapidly.
The upshot is that the replacement timer is going to go back to doing what the old one did, which is keeping a handful of water-intensive plants happy. And for the garden irrigation system, I’ll directly connect that to the water barrel, by hand. I guess I’ll set a timer on my phone to remind me to shut it off. So there will still be an opportunity for operator error. But there seems to be no way to automate the system fully, using rain barrels as the water source.
And so, my complete garden irrigation strategy has two parts. If I’m home, and there’s water in the water barrels, I’ll water the garden with rain water. Hook the hose up in the morning, unhook it many hours later. But if I go away for an extended period of time, I’ll have to switch the irrigation system back to its current setup using municipal (pressurized) water. Using high-pressure water is the only way I can automate the system with a hose timer, and still have enough flow through the system to feed the 150′ of drip line adequately.
Arguably the most important choice that I made when setting up this garden irrigation was to go with 1/2″ dripline throughout. As it turns out, the half-inch line is AC/DC. It works well with either a high-pressure (municipal water) setup, or a low-pressure (water barrel) setup. It just takes five times longer to water the garden using the water barrels. But given that all I have to do is uncouple the hose when I’m done, that’s not much of a hardship.
