Viridian Delta-T Variable Speed ECM High Efficiency Circulator, Less Flanges - Standard (120V)

I have had this pump installed for about a year. I purchased it for the delta-T function and used it for that at first but not now. There are 2 reasons. One, it produces an irritating vibration at high speeds during ramp up. Two, the program timing that sets the speed (to get delta-T) seems to do its calculations while dropping the speed but the cycle is too short so that speed tends to drop too low before the system can equilibrate. Then it has to go through the ramp up to full speed and slowly drop again to recalculate the speed to get the delta-T. Does this constantly. My opinion is that it should just adjust based on a simple feed-back of delta-T with a longer cycle (so it doesn't porpoise) rather than automatically go through the ramp up to full speed first. My wishlist is: One, since it has the Temperature sensors why not display the S and R temps all the time? Would be very useful. Two, can't you calculate the approx. pump flow based on the current, (oh and display it) ? approximate flow is also very, very useful. Pump Quality is very good, but not great. Needs one more design iteration. I would recommend it as a pump in general, but you should expect to use the other pumping options rather than the delta-T.

o As quiet as 007 at speed 1 and 2 speed, louder at 3 and 4 o Pump should have max speed setting. Otherwise it causes velocity noise. o On long loop (~200ft), pump speeds up/slows down too quickly causing 'cold water sandwitch' which causes it to speed up and slow down. o Pump appears to run too slowly when S and R are about the same causing return to cool off too much (again, probably due to long loop) In summary I'd probably recommend it for shorter loops and I wish that it had min/max speed settings to address some of the shortcommings.