John Gayewski
In the Trades
A tempering valve mixes hot and cold water. If you fill the cold side with hot what will the mixing valve do?Wow. Thanks for all the responses. However, I think I didn't make myself clear as to what was being installed and/or asked.
Watts (and Grundfros) make a recirc pump that typically mounts to the hot outlet on top of the water heater. The pump has a clock/timer that tells the circ to move water at the set times, usually from 6am to 9am and sometimes at night or whatever the customer desires to meet their instant hot water needs.
A manifold is also installed under the farthest sink that will move a miniscule amount of hot water into the cold line when the pump is running. There is NO actual separate recirculation line on the system.
See: http://media.wattswater.com/IOM-WQ-500800.pdf
I've installed several of these systems over the years and they work quite well to get hot water quickly to the farthest fixture from the water heater. They also help in the winter with problem water lines that typically freeze inside walls, as the water is constantly moving (if the timer is set as such during the cold months).
If a tempering valve was to be put on the system, would it go before or after the recirc pump?
PS- Terry - thank you for the idea of the Grundfros Aquastat Clip. Tonight I just came from a job that does have the separate recirc line and pump that was wired to run 24/7. I indicated to the new customer that perhaps this is why he keeps getting pin holes in his hot and recirc lines. I was going to pick up an aquastat and well, etc tomorrow and install it for him, but this will save him money and me time so I can help other customers. Thank you as always. Bill
What is the purpose of the mixing valve? Is it to make more capacity for the heater? Or is this a boiler system that uses a mixing valve for saftey?
Without a dedicated recirc there is a scald danger whether you have a mixing valve or not.