LsFarm wrote:I have my supply/return to my shop slab as a primary loop, I have a mixing valve that can be turned down to 85" in the secondary loop, which is the floor system.. there is a Taco 007 pump running 24/7 circulating mixed water to the slab, so it stays at roughly 55* depending on how cold it is and how much heat the shop is losing to outdoors..
the primary loop runs constantly, and is therefore also at a steady delta-T.. so there is no shock of 40 gallons of 80* water hitting the boiler, when the slab wants heat.. the slab is sipping heat all the time..
This constant small load on the system also acts like a timer on the boiler,, about every 30 minutes the boiler runs and brings the water up to 160*..
Yes I do have a few pumps running 24/7, but they are .78amp, so about a 100 watt expense..
Probably better than your 'tankless' DHW heater trying to help out the AHS260,,
And YES that tankless is NOT plumbed right,, it should never be in series or in any way be able to 'help' bring up the boiler water temp, only bring up the water temp going to the taps in the sinks and showers/tubs/laundry.
Hey Greg, could you explain the delta t thing to me? Ive thought about running the pump continuously but in my mind the boiler would be running all the time. The highest return temp I've seen is 95* from the slab and that mixing with 180* water is shocking the system and dropping tithe system down as low as 145*. Thanks for the help.