Grundfos595926 Valve, Black

I had a plumber install a Grundfos circulating pump on my hot water heater a few years back and I installed my first Grundfos inline valve in our master bath, resulting in a substantial improvement in the time it took for hot water to arrive for the shower.Rather than using the half-bath sink, I use our utility sink in the laundry room multiple times a day to wash my hands after working in the garage, the yard or to just to wash my hands after being out and about, but again, I had to wait a couple of minutes for the hot water to circulate up from the hot water tank . I finally got around to ordering another Grundfos inline valve and with some difficulty, I installed it in the utility sink cabinet. WHAT A DIFFERENCE! It is almost as if I have hot water on demand. I should have done this much sooner.One pump at the hot water tank will support multiple locations throughout your house where the valves are installed.The pump, the installation, the valves and the stainless flex lines I used for each valve were not cheap. HOWEVER, the results are amazing.

Tried a cheap knockoff first that was a wast of money and time. Ordered this to fix it right. I think this one works better than the original which lasted for 7 years.

This valve works with Grundfos residential hot water recirculation systems. They save you water by bringing almost instant hot water to any part of the house, and also runs warm water through the pipes in winter, preventing freezing. This valve goes at the very furthest sink or accessible fixture from the water heater, and regulates hot/cold circulation.All fine and dandy, except that these valves tend to fail after a few years. The pump on the water heater just runs and runs, but I've been through two valves in the past ten years. If you have a Grundfos system you will probably have to replace this thing eventually. When number two failed I looked all over at local stores and they could not be ordered unless you replaced the whole system. Pretty crazy. Fortunately Amazon sells them through a plumbing company, so they are easy and fast to get now.I rated it 5-4-4 because it's a great unit, though any under sink installation can be a pain, and it's expensive for what it is and does.

Replacement very easy and works same as original.

When we bought our house 18 years ago, the builder installed a Grundfos comfort hot water circulator pump. Other than learning how to set the timer, I never paid any attention to how it functioned. Years ago, hot water started running through the cold-water faucet line, such that if we wanted cold water, we needed to wait for it to flow through the pipes. That wasn't a big enough deal to investigate and remediate, so we lived with it. Then, recently, at times, when the cold water was running in one of our master bathroom sinks, the water would abruptly stop flowing, as though something had suddenly obstructed the water line. For the first time in 18 years, I looked at the plumbing in the cabinet beneath that sink and discovered that this gizmo had been installed. I did some digging and discovered that this valve was likely the reason for our years-long problem with our cold water flow. I found the valve on Amazon for a (relatively / comparatively) reasonable price, and it was delivered the next business day.It took me no more than five minutes to swap it, which simply entailed moving the existing four water lines from the old valve to the new one. Everything had been tightened snuggly by hand, so I didn't even really need a wrench. Looking at the old valve, it was 100% clear that the interior components had failed. When I turned on the water after installing the new valve, everything worked like a charm for the first time in years: At least so far, hot water has been flowing from only the hot water faucets, cold water has been flowing from the cold water faucets, and the cold water has not abruptly stopped flowing in the master bathroom sink. I now wish I'd looked into it a long time ago.That said, although the price on Amazon was upwards of $20 (35%-ish) lower than what I'd seen at other stores, after actually seeing and handling the part, I'm still surprised by how expensive it is "for what it is." It's plastic, and the interior components appear to be cheap flimsy plastic, akin to what you might find on the interior of a mid-range shower head. I guess I take some consolation in finding a "relatively" good price here on Amazon and that I didn't pay a plumber a hefty markup or for labor to install it. Also, because the Grundfos pump itself is now beyond its 18th year, I suspect that we'll need to replace the pump before we need to replace this valve again.

Put in the new piece of junk - er, I mean Grundfos P/N 595926 as the last valve had failed. Installed per the instructions - but the valve doesn't operate properly per the check instructions and the water hammer has transferred from the hot water side to the cold water side. Per their instructions, to check for proper operation, 1. close the angle stop valve for the cold water below the sink - Check! 2. Open the cold water faucet - Check! 3. Check that when you turn on the cold-water faucet, the flow of cold water gradually decreases and stops as the bypass valve closes - NOPE - all I get is water hammer, leave it running and you get hot water.So, I thought I'd go to the troubleshooting guide - under "too much hot water on the cold-water side", it says that the valve is not installed properly... Well it is installed properly, so I thought I'd call Grunfos and see if they had any support.. No number listed on their website, but you can fill out a form and they will get back to you soon... Over an hour has passed by, so I'm not sure if they measure time geologically or what.For all those stuck with Grundfos system, I am right there with you - held hostage by their faulty replacement parts. For those thinking about Grundfos - I cannot recommend - lack of support and faulty products.