595926 Sensor Valve Fit for watts premier 500800&500805 and grundfos up comfort Series Instant Hot Water Recirculating Pump System 367010 Thermal Bypass Valve Five Year Warranty

Great do-it-yourself project. Plumber wanted over $500 for parts and labor. I installed it for $40 in 15 minutes. Do not try if you are not familiar with fixing any plumbing.

Great replacement part.

I initially got this bypass valve to add another instant hot water zone on my house. My new tankless water heater has a built-in recirculating pump that can use either a dedicated return line or the cold water line, and it's in the latter configuration that I'm using these valves.This one appears to be a direct copy of the Grundfos bypass valve that came with the water heater... it should fit as a direct replacement. For now I'm holding it in reserve as a backup. The original one came with the extra hoses and adapters needed for installation and this one didn't. That's a good chunk of the cost difference if you're not replacing, but adding a new one.Overall, we're not convinced that using the cold water return is the best option for us, since we don't like the warm (or hot) water coming out of the cold side of the faucet. For that reason, I've paused expansion of my installation to other faucets for the time being.

So far this valve is very quiet and working well. It replaced a stainless steel valve that made all sorts of noise.

Easy install and works perfectly

Replaced my old valve with this one and it worked great.

IMPORTANT UPDATE 10 March 2025 16:14 PSTDocking one star. So... had this installed along with a pump on the hot water heater and it worked fine for two months. Then, kind of suddenly, the kitchen sink flow went to almost nothing. Checked faucet screens and found some tiny black debris. Cleaned that out, but still very low flow. Removed stop valves but they were clear. Finally, after seeing a YT video where the gentleman used this rather innovative technique, I backflushed the faucet lines with a garden pump sprayer and the black bits you see in the photo came out. Much better flow, but still not right. I expect the cartridge has some more of those black bits in it and will need to be replaced.SUMMARY: Apparently there are quality control issues. The valve does work. I tested it thoroughly, but apparently the finish work on the valve is lacking. You can use it, but flush it out thoroughly beforehand. It would be good idea to install screened gaskets inline before your fixture, also, if that's possible to save you the hours I spent tracking down the issue with my kitchen faucet.You need flex pipes to fit the valve to your existing hot and cold water valves, and then flex pipes to fit between the sensor valve and your faucet connections. This valve is used in conjunction with a circulating pump that you install on the hot water OUT line of your water heater. I installed on a tankless type water heater, so double check on YT to get details if installing on a regular tank water heater to be sure it's similar.THis setup typically, as in my case, uses the cold water line as a return line, which does mean that you'll need to run the cold water for 30-60 seconds before it runs cold. It'll run lukewarm before that, but the advantage is,, of course, hot water right away on whichever faucet you choose to install it on.I have a Watts brand sensor in the bathroom and this one is a bit smaller but it works OK and hopefully will last at least as long as the circulator pump. My reservation about durability owing to smaller size is the only reason I didn't go for five stars.One suggestion is to put your pump on a smart outlet so it's not able to run 24/7, increasing your energy cost. Also, on the pump, get one with three speeds and a flow switch, which will also maximize efficiency and keep costs down.

This valve looks and feels identical to the oem. I havent installed it, but I will report any issues upon installation. I took one star off because it comes with no parts required for its installation - it needs two 1/2" Female to 3/8" Male Reducer Adapter, because standard faucet hoses wont fit without such adapter on each size.