Just got a new water heater and the plumber insisted that all recirculating pumps should now be installed to recirculate hot water down at the drain valve instead of on top of the water heater. Is this the best place for the GRUNDFOS, b/c I think their website says to install at the top of the water heater.
BTW it is a 20+ year old GRUNDFOS UP15-18SU and was wondering what the lifespan of these things are? I don't have a timer on it so it runs constantly. Now debating if I should just invest in a new pump or add a timer to this existing one. Plumber installed shutoff valves on both sides of the pump.
As mentioned above 20 years is awesome, you must have really good clean water. While you're at it with the timer you might want to pick up an aquastat, no sense circulating water that may be maintaining temp.
Semi-professional plumbing designer
Enjoying life in SW Florida
The connection to the water heater can be at either location. The pump should always have had both valves and a check valve. Use a timer and close the valve BETWEEN the pump and the heater until it just maintains the temperature of the returning water. This will maintain the water temperature, save energy, and reduce erosion wear on the water lines.