Watts Instant Hot Water Recirculating System

Recirculation is primarily about convenience and comfort and saving water. It is not really about saving energy or money.

Without a dedicated return line, you will have the issue of not having instant cold water. Whether this is an important issue for typical bathroom water use is up to you.

economy

With the recirculation system, you use more energy keeping the pipes warm. Without it, you use more water to get the hot water to the sink. It is up to you which is more important.

The more I'm thinking about it, the more I think I should use my $200 for something else. Maybe save it for a new water heater.

Thanks for all the input gang!

Most people not only pay for the water, but also to dispose of it, so the small cost to recirculate to minimize that waste is offset, especially if you've insulated your pipes, and you put the thing on a timer so it doesn't run when nobody is home. Even if you have a well, you have a cost of water...unless you have an artesian well, you pay to pump it out of the ground. So, if you don't run it all day, you could actually save money, and have the convenience of much quicker hot water.

If your house and piping is open, say from the basement, adding a return line isn't all that difficult. With the unit I have, the only sink where there is noticable warm water is the one furthest from the WH...all of the others never see enough recirculated water to be warm. Then, if I flush the toilet, that purges the warm, so I have cold immediately (unless the pump happens to be running at that exact time!). So, I really like the convenience, and the idea that I'm not dumping those extra gallons down the drain every time I want warm or hot water.

I have mine adjusted so it shuts off at just about body temp. Full hot is not far behind, and my shower taps off there so it gets full hot very quickly. At the sink, I have warm to wash my hands, etc., immediately. Not all systems are created equal since most can't be adjusted to get it just where you want it.

they will work as intended. the biggest draw back is the cold will have a bit of warm water in it but unless you are wanting a cold glass of water from the tap with no ice it wont really be a problem.

if you install a timer or sensors your pump wont come on except when you use hot water so trying to say it uses more energy to keep the pipes warm is just a matter of initial cost

Grundfos/Watts

I put one in our house 3 1/2 years ago as the water heaters are in the attic and the kitchen, where we need hot water sooner rather than later, was taking 4 minutes to warm up. That's alot of wasted water.

Cold is warm often but the trade off seemed worth it and there is an icemaker and water tap on the fridge.


I plugged the pump into a timer with mulitple periods and weekend periods etc. The pump has its own timer but not enough periods to work with so I plug the pump into a better timer

I run in the morning and then afternoon evening. About 7 hours avg per day. It does waste energy by running hot water all over the house and back needed or not. So the gas water heaters fire up alot more often.

Again, the waste of water in the kitchen (farthest from the heaters with a run well over 100 feet) was the issue.

But here is my main concern as of 4 am this morning.....I just stayed up all night fixing a leak in the kitchen. That is where the crossover valve is. The leak was caused by cavitation. Now I'm wondering if the circulator caused this problem due to the "dead head" or just shear water velocity. Or if there is another corrosion related issue.

I'm off to search for ideas on installing a small on demand heater under the sink.

Also, I learned that old water based flux is evil. I re prepped my patch 3 times then read elsewhere in this forum about this problem. Ran out and got some oatey 95 and solder flowed perfectly.

Cavitation happens at the pump inlet, and sometimes at the outlet on big ones, so I doubt it was the cause.

That circ is designed to deadhead and is not capable increasing pressure enough to cavitate.