I have a Hunter irrigation controller (ICC model from 20 years ago).

It seems recently it's been watering (or not) at weird times. I've been noticing that actually the time setting is wrong. It's AC powered and while it doesn't lose programming upon power loss, it can lose the clock time. This is generally protected by a 9V battery.

However, even after replacing the 9V battery, I'll notice that the time continues to be wrong on occasion. Perhaps the replacement battery was already dead and I keep losing AC (just briefly - enough to affect the controller but not enough to cause the clock inside the house to reset).

In any case, looking for some help. How do I troubleshoot this to determine if there is a power issue (AC or DC), power supply issue (transformer), electronics / computer issue?

I don't think I'm losing AC (not that I've noticed). I can try replacing the battery again although it's a new pack. I think primarily trying to distinguish between an electronics issue and transformer issue. I'm guessing that a transformer issue shouldn't really manifest unless I also have a battery issue.

So sounds like it's an electronics issue (and need to replace the front electronics panel ($150). But given the cost, would prefer not to just try this if the problem could be something else.

20 years old is outdated tech, it would be a good time to upgrade


plenty of new BT/WiFi controllers that tap into the national weather service, have a plethora of time options and water saving features as well as reporting.

I run the Rachio, no pins to set, dials to mess with, issues with power outages on keeping time.
It adjusts schedules for time of year, and report of pending rain etc and I can run it with the app.

There are other manufacturers of wifi controllers, at 20 years it's time to upgrade..

Rachio Link

Hunter has smart irrigation system controllers as well..

Hunter Link

I've also got a 20 year old Hunter irrigation controller, the Hunter EC.

I've lived with it for almost 17 of it's 20 years and it has always gained time, and does so rather quickly.

What that tells me is that it's using a clock chip to do the time instead of doing it with 60Hz AC power.

I have to reset the time around every 3 months or so. Annoying, but I can live with it.

As long as it does the job for me, I'll keep it. I have no need of one that taps into the National Service or water saving features as it does that very well just as it is.

In my case, the time can be suddenly off by 12 hours or so. Fast by minutes is okay - I need to reset 2x per year for daylight savings.

But this is causing irrigation to be at 2PM in the afternoon instead of 3am at night.

I moved on to a couple of Rachio 16 zone controllers about 5 years ago. I can control all 24 of my zones with my phone. Super easy. Like they say, "There's an app for that."

Thanks - I'll look into the smart controllers. If there isn't much cost delta, maybe that's the way to go.

You being in California?, these controllers reduce water use, might be some kind of government rebate on upgrading. Check your local water utility...

For budget minded try Orbit. I put one of these at my sister in laws when she bought her home, had a really old at least 20 if not 30 year old controller, similar issues, wouldn't run all the zones, hard to keep time set, etc.

Snap to install, easy app setup and programming does everything the Rachio does for half the cost. $90 at Lowes or Home Despot...

Orbit B-Hyve 8 Station Timer Link

I agree with others that a 20 year old controller is time to upgrade.

I like the Hunter sprinkler heads (though use a Rainbird controller) as the Hunter heads are quality compared to the others.

My 20 yr old Hunter controller was having all sorts of weird problems. Put in a Rachio and love it. Easy installation and has been problem free for 2 yrs now

Replace it. It’s served it’s time.