Trying to understand the following: how valve communicates with pump? My understanding, valve has temperature sensor, valve opens when temperature in hot line drops below a whatever temperature set in there(like 85F or so). So, if pump set to ON - it will start circulating right away... But if pump set for certain time…

Several of these answers are incorrect.The thermostat is not built in to the pump...if there was a thermostat in the pump, it would run and turn off almost immediately because the water is being pumped out of the tank and would satisfy the set temperature very quickly or not turn on at all because the pump is connected directly to the tank outlet. The PM Comfort Auto has a temperature sensor that attaches to the cold line to the HW heater...the comfort system runs all the time...against itself when the comfort valve is not open.It does not have a thermsistor...it is a mixing valve. When the temperature of the water approaches 95 degrees, the valve closes just like a thermostat in a car does.The amount that of hot water that returns is not "miniscule"...it is the same amount as you would use to wait for the hot water except that the pump only provides 2-3 gallon per minute...as it approaches 95 degrees the valve starts to close and the flow reduces. As the system continues to run after the initial start, then it is correct that it a small amount that goes back to the tank.

You mount the pump at the hot water heater, what type of valve is at the farthest point to allow water circulation? I have slab construction. Thanks

Your kit should have come with the bypass valve. This is mounted under any sink between the hot and cold water pipes. Best location is at the farthest point from the hot water tank. I actually have 3 of these bypass valves installed because of the way the hot water is distributed throughout the house. You should have a flex pipe between the cutoff valve and the faucet for both the hot and cold. These flex pipes feed the bypass valve and you will then need two more flex pipes to go from the valve to the faucets. If your kit did not come with the bypass valve and pipes, you can order them online. The valve is referred to as a comfort valve, also from Grundfos. This system works great. I have the timer set to come on about an hour before I get up and run for 3 hours in the morning and 3 hours in the evening.

If I leave the system 'ON' at all times (and don't utilize the timer), what's the energy usage equivalent?

If you leave it on, all the time you are basically putting a radiant heating system into the areas where your hot water runs... It made out hot water heater bill insane. Turned it off, and my hot water heater uses a 3rd or less of what it used to. The timer needs to be coordinated with when you need hot water at the most distant fixture. I am adding a remote wireless control to mine so I can only turn it in when I need it and don't have to use the timer.

Is ithere any advantage to useing more than 1 valve in the system?

if you want instant hot water you need a valve at every sink. Our house has about a 60' run. I only installed 1 valve at the farthest point. The other sinks before it get hot pretty quick now but not as fast as the valved one.

Brand	Grundfos
Color	Black
Material	Bronze, Stainless Steel
Style	Circulator
Product Dimensions	10"L x 10"W x 10"H
Power Source	Corded Electric
Item Weight	6.1 Pounds
Maximum Flow Rate	9 Gallons Per Minute
Maximum Lifting Height	6 Feet
Voltage	115 Volts
Manufacturer	Grundfos
Part Number	GRU-595916
Item Weight	6.06 pounds
Item model number	GRU-595916
Is Discontinued By Manufacturer	No
Pattern	Pump
Item Package Quantity	1
Included Components	1
Batteries Included?	No
Batteries Required?	No
Warranty Description	2 years from the date of installation

GRU-595916 Recirculating Hot Water Pump Comfort System 25 Watts, Easy Install. Instant hot water throughout system. Entire Kit Included

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