How Hot Water Recirculation Pumps Work - Watts 500800 Review 

This was an exact replacement for the old one that lasted about 10 years. ru-vid.comUgkx7yWIKcrbA9KMHkGSfcgxW2lsjHT6B8Sh The top of my mitigation tube by my roofline was just a 90 elbow which allowed too much debris to fall down into the fan, eventually ruining it. Without this issue, I bet it would have kept running another 10 years. When I replaced this fan, I added an extra elbow joint so the top tube now it does a 180, which should solve that problem. The radon guys around here wanted to charge me a $300 diagnostic fee, then parts/labor (probably close to $600 total). I installed this all by myself in about an hour for the cost of the fan; it would probably be even easier/faster with two people. FYI the manufacturer's warranty greatly differs depending on whether you install it yourself (1 yr warranty) or have a licensed installer do it (10 yrs).

Excellent - video answered my main question that I couldn't find in the Amazon listing.

Hard to believe I'm the first commenter...I'm new to all this re-cir pump stuff but after buying and refurb/remodeling my mobile home and final resting place I decided to try this system for my kitchen sink...which is way on the other end of my place. So I found one of these units on Ebay and installed it. For me the install was a piece of cake, but I'm very mechanically inclined. I only needed one medium crescent wrench... Done! Beware...the two main fittings in and out of the pump use a "ONE" way valve. Once installed I had questions so I contacted the tech service hot line provided with the literature. I was amazed at how quite this unit is...as the tech guy said... these pumps are quiet and some are very quiet. My other concern was that the motor/cartridge housing get fairly hot. The Tech guy confirmed that yes it does...when the pump is operating. After 24hrs this has been confirmed. OKAY...now here's the rub. Instant "HOT" water? Not gonna happen. Hot water within a minute is acceptable. Now for the rub...The way this works is that it keeps the hot water circulating thru your water system...hot side to cold side constantly, or should I say warm side when not in use. The pump thermo sensor controls this. BUT...on the flip side...if you want "COLD" water it take as much or more time for that to happen...hence the rub or trade off. So for me...instead of waiting "Literally" 2 minutes for warm to hot water...I get "warm" water pretty much at the hit, and the hot within a minute...which is much better than my original system. So... okay...it does a pretty good job. Now the final test will just be time & reliability. I did a LOT of research and shopping around...and some of these pumps are ridiculously expensive! This original post was from an Eastman Nevercold 70601 under sink unit video. I do a lot of business with Amazon and the Eastman water heater top mount unit on Amazon is under $300 bucks. But essentially the same unit under sink mount is over $500 bucks! I don't get that. If anything it should be the same or less and they would sell a ton of these under sink units. They are really easy to install. So there's my take...worth a couple hundred bucks...and I'm reasonably satisfied...and that's no easy task.

For many people (those with water heater in basement) -- by far the best system for hot water recirculation is a gravity type system. Always hot water in hot water side, always cold water in cold water side. No pump required. No worrying about setting timer. No hot water in the cold water line when pump is running.

Well done video, thanks for posting it. I just installed one, have about a 40' run to the kitchen sink. Used to take a good 30 to 45 seconds to get hot water. It definitely helped with that, But, it takes even longer to get the cold water back to the faucet for a cold drink now. I'm retired and home all day, so have the pump running most of the day. Also the hot water heater runs a lot more now. Both hot and cold water lines in the run are insulated. It's certainly a convenience, but not a water or energy saver. I ended up running a separate line for a cold water faucet with filter for the sink.

Good informative video!

What the censor valve that goes under your furthest sink does, is it has a thermostat valve. When the water is at a certain warmth/heat it closes. Trapping hot water at your faucet. When the temp drops to a certain point that valve opens up and cycles that water through the cold line back to the water heater to be warmed up again. It’s not in a constant cycle through your lines. If you didn’t have that censor that’s what would be going on.

Good Job, The question that I have is with the advent of smart plugs... would the implementation of a smart plug be a good option in lieu of the timer. My assumption is that if power goes off for a couple hours then is has to be reset. It would also allow one to turn on the unit "on demand" in addition to any time schedule that are set. Being network attached, it would not require any reset for the power being off. I know the Grundfos unit has a level of battery backup but as you point out is the more costly option.

Great video. Can anyone please tell me if this is ok to install in house that has pelican whole house filtration system? I am concerned that the sensor valve will push the cold water back to the nutru softener and cause issues? Any help will be much appreciated. Thanks.

Great video thanks!

I have watched a few vids on this subject. I thought the pump does not operate until you open on the hot water valve. What I still wonder why the timer? The pump is on stand by. Isn’t it. Good vid

How do you know which sink is the furthest from the water heater? The furthest could be the sink upstairs or another sink depending on how the pipes were installed

Great video! I have one question: When the pump's timer is on, does the pump run all the time or only when the sensor at the sink "tells" it to? Thanks.

Hello, great explanation really simple to understand. i do have few questions please if you can reply quickly because i might need to install it in the next day or two. 1. does the valve the black plastic piece has to be installed in each unit separate? i have a multi house with several units, and they all use 1 water heater. 2. is there an option for the timer to be set for 2 times a day, moring and evengings? so people can enjoy it before and after work? 3. i did so where is the link for the install if you can add it please. 4. in those hours that you decide to turn the timer off or actually is off automatically, or for example if i want to turn it off all the summer time, because people rather have colder water, will that make the water in the pipes regular cold again, and fast cold water? or is it has to be set to heat while in installed on the water heater? thank you very much

When the pumped hot water goes through the sensor there is mains pressurised cold water on the other side of the sensor, how does that work?

Ideal situation is to pipe a dedicated hot water return line with a aquastat to cycle the pump on and off. Not always possible, so this is the next best.

Thank you for the video. Question about the sensor valve. If I have 6 sinks, I don't need one for each. Right? Like you said, install the sensor valve under a sink that is furthest from the water pump. So I only need to install 1 sensor valve for the whole house. Right? Thanks.

Funciona con calentadores de paso? Tipo bosch therm 8000s

Do you know the gallons per minute rating for that pump is? I was thinking of installing this for my mom but should she be expecting a higher water pressure at the taps? Thanks

I’m just confused with this device. Do you set it to be on each and every time you think you will be needing hot water. So in other words most people in my household will be showering between 7 and 9 am. So do I need to have it on during that whole 2 hour block or can I turn it on for an hour at 7-8 and expect it to be hot still at 9am? Secondly during the evening we will be expecting hot water so do I have it running between 4pm to 9pm or do I turn it on for an hour and it then still delivers hot water for the remaining time. In other words when it’s not running so you get cold, lukewarm water? Do you waste water by waiting for it to be warm? Having it be on too frequently won’t that cost your gas bill to skyrocket since you’ll be having the water heater running to keep the water hot?

Can this tipe of pump be install in a boiler?

I have two water tanks set up in Parallel - where do I install this circulator?

When the valve closes, isn't the pump then pumping against a closed system? Is that not bad for the pump?

After installation of the Watts Hot Water Recirculating Pump,I started using it right away. As long as the pump is running all is fine, but when the pump shuts off I have pipe bumping at the faucet where the bypass valve is installed, when running water in the kitchen. I installed an arrester on the Hot water side at the by pass valve, and still have bumping when running water at the kitchen with the pump off, I turn on the pump and it stops. Should it take an arrester on the cold water too, to stop the bumping?

I recently replaced the pump with a new one. The question I have is how to connect to an under sink water filter? I m not sure of the correct piping for it. The sensor valve seems to be working correctly as the inlets for Hot and Cold to the sensor valve are piped per the instructions to the sensor inlets. However for the cold outlet side with a standard water filter cartridge housing water filter how should it be connected? Any help is greatly appreciated.

Do you use the heat trap installed in the anode rod with this recirculating pump or does it have it have to be removed first?

Could the pump also be mounted under the sink? Long as the pump is hooked straight to the water valve then hook up the sensor valve it’d be the same as putting the pump by the water heater.

Shouldn't the cold water line not be "warm" if the check valve shuts off when it senses hot water and stops sending that hot water into the cold line? That is really the point right of the valve otherwise you would just have hot water in both pipes. The valve is there to only circulate water when the hot water cools down. So, for instance, the check valve starts working when the hot water gets cold, then sends that colder water into the cold water line. Then hot water line gets hot again, and check valve shuts off and keeps hot water available for use, while the cold water pipe has cold water. I agree that the water won't be as cold as it normally would be because there is a threshold on the valve and it has to send some warmer water into the cold line, but would you say this water is actually "warm"? What was your experience like after you hooked it up? Is the cold water line actually feeling warm to you, or is it just a little warmer than what it used to be when it was fully cold? I wish I could see a graph of how the temperature changes.

We did this with this unit..... the cold water spigot in the sink works just fine after a few seconds it gets cold as usual....the problem we have is the shower in our master bath. The cold line is "always" scalding and never gets cold....even when we turn the hot water spigot completely off the cold always stays scalding..... what gives?

Best video and explanation I’ve seen on this subject. Question: Does the pump have to overcome the water pressure on the cold water side, in order to force the cooled down “hot” water back to the water heater? And if so, isn’t the higher pressure a potential problem? Thanks.

I connected the pump a day before I installed the little circulating piece. Do you think I did any damage to the pump considering the water wasn't circulating through the pipes?

Hi there, How hot the water gets on your cold line for us to use, it lets say when someone is getting a shower and someone else is using the sink faucet? Pump is going to be pushing hot water into the cold lines and eventually all the way back to the water heater, isn't it? also will try to push the hot water back to the street, do we have to install a check valve between water mete and house to prevent water to go back to the street? Thank you

A plumber installed this Watts hot water recirculating pump last August. After 14 months, the pump starts making vibration buzzing loud noise. I asked the plumber who installed this Watts hot water recirculating pump and he said he doesn’t know why and he can’t fix it. He told me that he will replace a pump with the cost of $450.00 . That’s is too high. Is anyone have the same issue as mine? Any advise or video how to fix the noise issue? Thank you in advance!

Great video! Question: Does the pump have to go at the hot water heater, or can it go under the same sink as the bridge valve (or anywhere else in the hot-water line between the heater and the valve)? I would think the location (beginning or end of the same water-line) wouldn't matter where in that line the pump goes, no? Thanks!

Hello everyone - I was about to get this solution installed but then a friend who is an engineer in the field warned me that the "side-effects" of this solution are: 1) the cold water in the circuit will no longer be cold 2) when the pump isn't active and the hot water cools down the valve opens and the hold and cold water mixes - so you get a warmish water a few meters down each of the cold and hot water tubes. Can anyone here comment on this based on your experience using the product ?

We have a tankless water heater..can you still install this device.

Will this unit be a good idea to purchase if I have one bathroom sink that is on an exterior wall that freezes?

I'm considering this system but I have heat traps on my water heater. Do they have to be removed for this system to work?

Would it be better if I installed 2 valves, one on each side of the house?

Does it work well with tankless water heaters? Would it cause the heater to be turned on continuously? Thanks.

Would it work under pressurized cold water pipes?

I think I will be installing one of these but could I just run the sensor cold return back to the cold input on the water heater? I have soft water on the hot line to the kitchen sink, but hard water (for drinking) on the cold. I have access to run the line in my basement back to the water heater. If I do run a separate return, what size line would be adequate?

How long have you seen this particular pump last along with the valve? I noticed the warranty is only 1 year where the Grundfos is 2 years or up to 30 months from date of mfg. If it's a $50 difference between the others and this one IMO the extra $50 is worth at least an extra year of warranty.

How many time slots can the timer be used for?

In minute 2 your a little wrong by saying it’s always flowing through the temperature sensor valve… the valve opens when it detects the water temperature on the hot side is 90 degrees or less give or take 4 degrees… the temp valve under the sink will open and allow hot water to flow to the cold side (that’s where the pump pushes it through) the temp valve closes when it reach about 100 degrees or so… yes your cold water will be like for a little while but remember it’s mixing with the cold water so by the time you go to use the fixture it may even be cold alrdy you won’t even notice it.

I have one cold water pipe that get frozen because of a poor insulation somewhere inside my walls. Do you think that this will help the cold water line to have warmer water in it if I schedule it to Run every 2-3 hours or so. It's kinda a different use but I'm just trying to find a solution without opening alot of drywall and searching

If your hot water is 40 feet away it's still going to take as long as it did before to get to the shower head or sink.

if the cold water line has to wait for cold water, does that mean when you flush the toilet, is it flushing with Hot water?

I've had mine installed for about 3 years now and it just "quit" working... I took it apart and noticed the "wheel" inside easily stops turning... was wondering if that could be the reason it's no longer pumping... any suggestions on fixing that or what are my options other than purchasing another pump...

Wouldn't this pump raise the water psi way to high for appliances and faucets when its on and shortening their life?

I don't understand how this will push pressurized hot water through another pressurized cold water line? Wouldn't it just dead head? I would think to work properly, you would need to run a return hot water line back to the tank.

Great Video but those mixing valves suck and are not reliable. What they cause is the cold water in most of the house to become hot. I have tried this and I am currently looking for a way to run a dedicated return line. In a ranch you could wait over 3 minutes for the hot water at the far end of the house.

How hot is going to be the cold water?

Circulating hot water in your cold water line is a terrible idea if you like instant cold water. There’s also the whole bacteria thing.

Dead on arrival. I paid a plumber $200 to install and uninstall this pump because it was dead on arrival. Don't buy one or if you do, save your receipt & box for a few months in case you have to take it back to the store.

Dude!....Volume too low!!

Most Newer water heaters have heat traps rendering this type of recirculation pumps useless

This is such a stupid idea. You are heating not only the hot water system piping but also the cold water system piping. So instead of running the hot water until it gets hot you will run the cold water until it gets cold. ???? what about the additional dissolved metals in the hot water and the definite consumption that will occurr as a result of using the cold water. Come on this is ridiculous!