Currently our circ pump between boiler barn and the house is a fixed speed Taco 0013, sized per the Taco datasheet. It's done the job but I have no idea if it's over or under sized.... it's just worked. I've read about variable/multispeed pumps but don't understand what part of the control system decides when or why to use first, second or third "gear". Since our system is forced air and the fan is turned off when the thermostat is satisfied is there any benefit to using a variable speed pump? We're redoing the boiler barn plumbing to add the storage so if there's any advantage to upgrading to the latest, greatest pump, now's the time. Another dumb question.... are folks with forced air/storage systems turning off the demand circ pump when the blower's not on? It seems possible the electrical energy to get that big slug of water (~350' round trip) moving again every time the fan turns on may be greater than the wasted thermal energy lost circulating all the time. I guess that depends on the time duration between the tstat calling for the fan. I can see keeping the circ pump running all the time could hurt storage energy. Finally... if most systems stop circulation during fan downtime, having the circ pump in the house vs in the barn makes sense but our Taco is quite noisy. Has anyone found the Grundfos or others quieter? Thanks guys. Almost looking forward to winter... almost. Certainly looking forward to football and deer season!