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.

I have used this to test 7 solenoid. I use it to test the solenoid on the reversing valve to see if it’s energized. I also use this on my ice cube relays and transformer. So far, it worked as expected. However, it does not work on pumps; especially if the pumps have a tick body. The ticker the frame or body of the pumps, the less it’s going to work. I got it to test solenoids and not pumps. That is why I gave it a five start. I am getting two more.

I was looking forward to getting this tester. My plumber had a competitors model and it worked very well. Unfortunately this tester was inconsistent in demonstrating the rotation of my water pump motor. The one my plumber used showed proper rotation every time it was placed on the motor, but this tester only showed rotation some of the times. It seemed to have difficulty starting to rotate and continuing to rotate.

Great Tool

Very helpful

This is a handy little tool for indicating electrically energized solenoids and motors as well as motor rotation on some types of pumps. It's made in Sweden by Geonordic and seems to work fine for indicating rotation with Grundfos brand circulator pumps, but not so much with the Taco 007 Series circulators pumps. I don't know if it because the magnetic field from the Taco motor is just too weak or if it is interference from the amount of cast iron in the pump motor housing and flange. With larger multi pump installations like you have in commercial boiler rooms, this little tool makes it easy to tell when the pump motor is energized when there is otherwise either too much background noise or vibration from other nearby equipment to hear or feel if the motor is running. It also works for determining the rotation of small shaded pole motors used in things like bathroom ventilator fans. You can see and feel the little red and white disc rotate inside the testers housing when it is placed in a magnetic field. It was a little expensive for such a small tool and it may not always sense the magnetic field from every small motor, but it is still a useful thing to have on your key chain.

Great to have on my keychain for work. Can easily tell if a pump is running or a solenoid is working

Doesn’t work that well