I would like to install a second comfort valve in the upstairs bath. The existing valve is in the kitchen on the main floor 3 feet above the pump. The pump head lift on the UP15-10SU7P is 3.5 feet and the bathroom is 13 feet above the pump. Does head lift matter in this case as hot water is already being pushed by mains pressure.

Is your pump connected to the water heater or in the kitchen cabinet? Tom

My pump is connected to the hot water tank in the basement.

Does head lift matter in this case as hot water is already being pushed by mains pressure.Yes it does! Let me explain. When you open a hot water faucet upstairs the water is being lifted by the pressure behind it. Shut the faucet off and the line's static. It then falls on your little pump to make that 13 foot lift and circulate the water. Cheers, Tom

Makes perfect sense Tom. I have a second Grundfos that will go to 15 feet. Thanks a million for your help.