Hunter HC100FLOW Irrigation Flow Meter, 1 in. for Hydrawise Controllers

I purchased the 1” Hunter flow meter primarily to measure water usage on the lawn to determine correct water usage. I am using this meter with the HPC Hydrawise compatible face panel replacement with my old (2017) Pro-C controller. Many recommendations for watering a lawn are in gallons per square foot/week or inches per square foot/week (easily convertible to gallons). Irrigation controllers typically are time based. With this meter I can now get a good estimate of how much water is going onto the lawn and make adjustments accordingly. I installed this meter between the anti-siphon valves and the zone valves boxes. According to the installation instructions I left about 12” straight inline on the intake and exhaust sides. The instructions also recommend to remove or bypass and drain the meter if you live in a climate where you need to winterize. To do that I installed the meter with L union PVC fittings and built a replacement piece with compressor fitting for winter blowout (see image). The meter has a solid brass body so can imagine would not do very well if full of water and frozen. One other consideration is that this meter does have some drain on water pressure. According to the charts in the installation manual I can expect about 4psi drop using the 1” meter and 10 gallons/min draw (my maximum). With a starting pressure of 62psi that was not a problem for me. Initial tests comparing the utility water meter (in cu/foot) and this Hunter meter (gallons) show that they are fairly close. A much cheaper way to get water estimates is with a tin can and measuring stick. That works unless you have subsurface drip irrigation, but in any case not as much fun as measuring/controlling usage from your laptop/phone. So far I have been able to reduce lawn water usage in half using measurements from this meter. I was overwatering using the time based irrigation method. Using this meter and the Hydrawise app to adjust for weather and seasonal variations is working great.

I added this simply because I am away from home often, and it has the great feature to be able to sense if water is exceeding what is normally flowing during a watering cycle from a zone, you will get an alert. You can then react and shut down the system and avoid major issues. I have also found it really interesting to see how much water each of the different zones has been using.

Adding this flow meter dramatically increases the usefulness of the Hydrawise sprinkler management system. I dug up the area around our back flow preventer device and added this flowmeter downstream in a straight length of pipe. Requires straight pipe at least 10 inches upstream and 5 inches downstream of the flowmeter. The signal output flex conduit is relatively short, but by loosening the mounting screw I was easily able to rotate the meter display assembly to allow the flex conduit to exit directly towards my junction box. The thread on the end flex cable takes a M6-1.0 nut (from Home Depot) to mount into a hole in a junction box.

Works as stated

Just replaced my Hunter HC100 flow meter. First one installed January 2021, failed June 2023 (warranty is 2 years, but from the *manufacture* date, which was June 2020). The reed switch on my original unit failed open circuit. No response in two months from Hunter tech support regarding options, so just bought another. But! After several hours digging, pulling old unit, and installing new HC100, noticed there is a back-up reed switch, not documented in the manual but shown inside the lid diagram (which of course I could not see down in the hole.) So next failure, I’ll try connecting the back-up before the expense and effort of replacing the entire meter. The HC100 flow meter in conjunction with my Hunter ProHC-1200 controller lets me configure irrigation and then detect problems via the Web interface. Have found cracked risers (back when I could afford water for turf) and cracked pipes where neighbors turned too wide and ran over sprinkler heads. With my top water rate in Vegas $15/1000 gallons, tracking irrigation performance is very important. Regarding shipping, the HC100 was shipped via USPS in a plastic bag, resulting in a beat-up box. Meter seems OK. You would think with something heavy costing $150 they could afford to ship in a box?

The flow meter was easy to install. I need it to show if my irrigation system has any leaks since the main meter to the house is fifty yards away and down a steep hill. Now I can quickly check for leaks after repairs. I have older Hunter irrigation controllers, so I could not connect the meter to them for automatic leak sensing.

Well worth the money and easy to install. Monitors water usage when used with HC12 controller. Any over or under usage of water and an email is sent. Unnoticed broken pipes and you could have 300.00 water bill. With this your protected from page bills.

I can now watch for broken lines and sprinkler heads. I added a dummy channel to the Hydrawise controller to know how much water I added to the pool.