Rotation Tester and AC Detector for Circulating Pumps etc

Bought a house that had a Watts 500800 Instant Hot Water recirculation system. There were two "sensors", one in the kitchen, the other in the master bedroom. These sensors are valves that are installed between the hot and cold lines under a faucet. They close in response to hot water, and open when the water cools. The idea is that, when the "hot" water near the faucet isn't hot, the valve opens, and the pump (which is on the water heater hot output) forces water through the hot line, then through the open valve, into the cold line. When really hot water reaches the valve, it closes. So, when you then tun on the hot faucet, the water is instantly hot. Correspondingly, because some warm water has been pushed into the cold line, when you turn on the cold faucet the water is a little warm, but it quickly cools down as the hot water gets flushed out. The system didn't seem to do much. Took a long time to get hot water, especially in the master bedroom at the far end of the house. I wondered if the pump was working. I could hear a noise, but didn't know if it was actually rotating. Eventually, I bought this indicator, and held it up to the pump, at the water heater. It didn't spin. So I got a rubber mallet, and gave the pump casing a couple of fairly gentle taps. Held the indicator up again - it was spinning (more slowly than I expected, but definitely spinning). That night, my wife complained that the cold water in the master bedroom was running hot. So I tested the sensor/valve and, sure enough, it wasn't working - it did not close, even when the hot water faucet was pouring out near-scalding water. We had not experienced the "hot cold water" before, because the pump wasn't spinning, but thanks to the rubber mallet, the pump had been constantly pushing hot water into the cold water line. Next day, installed a new (steel) sensor/valve. Now everything is working well. Since I probably won't need to use the indicator for anything else, I've taped it to the pump. See video. Turning like a champ. So an $18 outlay saved me from paying a plumber, and helped me turn a failing system into a working one.

Love this I lost my previous one and it’s better than the other one the disc it does not fall off after a few smack from Being dangle . 10/10 would recommend

Quality

Never worked and to return it would cost me more than it’s worth. I’ve been in the Hvac trade for 30 years and I work with pumps every day. I thought this would be a cool little gadget to have to check rotation but no. This is one of those items you will want to return but it doesn’t make sense. Complete china trash.

Mine arrived in fine shape, even though it wasn't packed very well, just in one of the paper Amazon bags. It works fine on Grundfos UPS 15-42f pumps; I could have used this thingie 20 years ago when I first had to troubleshoot this hydronic system. I'm still not sure if the rotor is actually turning or if it is just a rotating magnetic field (but I happen to know it is because I stuck a screwdriver in there!)

Aún no la eh usado, se que va hacer mucha ayuda

Every technician should carry at least one of these. Great tool

Doesn’t work that well