not really - might be marginally more efficient if the water in goes to the highest heater fitting and the return goes to the lower one, but not so you'd notice smile

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics