- Reaction score
- 13,478
I don't know why dual pumps are not more popular. Given how long the better pumps last and how unreliable zone valves tend to be, I've always thought it a good idea. I put a dual pump system in 20 years ago for someone who was fed up with valve failures, and AFAIK both original pumps are still going. And in the days before intelligent pumps you could set the HW pump low and avoid having a bypass regulator. Then there was the SMC controller 3-port pump. Anyone remember those?