Recirculation devices

[pushkins]

My h2o tank is a mile away from the master bath (OK not a mile but it feels that way at times), I was going to add in a tankless unit but have decided against it. I've seen those little pumps that you connect to the furtherest lines that recirculate the hot water, my question is, has anyone used them, which is better the electrical models or manual and do they actually work cost effectively?

[Fischer]

They have them at Costco for $180 and they work. Not too much in the way of plumbing. Hook them up at the furthest faucet and plug it in. Very low electric draw when the pump is working (33W I think). Supposed to save 12K gallons a year.

[Fischer]

Manual I have not used or installed. The problem is running extra lines, and it's a gravity feed. Now there may be another type that I'm not aware of when you say manual.

[pushkins]

Thanks Fischer, the one I was looking at is called a "Lobster" you can stop laughing now, but it kinda does look like a lobster.

[CR500]

Do they keep the water in the pipe hot all the time?

I wonder what the cost differential is between the amount of water saved vs the additional fuel required to make up for the heat lost through the plumbing.

[shock]

I had the same issue and purchased a Watts Premier Hot Water Recirculation Pump at Home Depot. Prior I did some research and I think it was an Amazon review that they just used the sensor part of the kit. I attached the sensor to my furthest sink and it worked like a charm. No pump needed. The water isn't super hot but much better than it was before. I returned the pump kit and purchased the Watts Premier Sensor Valve Kit ($40) from Costco online and so far I'm happy! I added another kit to the other side of the house and it doesn't seem to work as good but it is better. Good luck!

[AllanJ]

Systems that require that a return pipe be installed can deliver full hot water quickly to the faucets served. Sometimes they are calibrated to (or the return line is so skinny as to) not sustain the hot water pipe contents at full temperature and thereby reduce heat loss.

Systems that use the existing cold water pipe as the return pipe must maintain the water temperature somewhat lower since you won't be able to get cold water until the warm or hot water occupying the cold water pipe has been flushed (into your sink or shower). These systems are OK for casual use such as hand washing. But you will get temperature changes in the middle of your shower as the water gets used and the pipe contents changes from recirculated warm to new hot plus new cold water.

As far as determining the heat loss from the pipes, this is a science project requiring considerable analysis and also ability ot measure fuel consumption and quantities of water used.

In winter, when you have your furnace on, any heat "wasted" by recirculating domestic hot water is not really wasted; it helps heat the house.

[shock]

I did insulate all of the accessible hot water lines in the house. It should be noted that my cold water is also a little warmer with the device attached.