chevymatt wrote:The garage zone is at 125* and the return is coming back at about 95*. I noticed this morning my boiler temp was down around 150*. My circ pump is a grundfos 15-42 1 phase no adjustment and the thermostat is one of the old rotary ones.
Maybe I should invest in a newer programmable thermostat. Does the temp drop in the boiler scare anyone else or just me? Or is this pretty normal?
125 deg. is the upper end in my opinion. Jack the temp down to 115 deg. f. for starters. You may have to go lower yet, say to 110.
As previously questioned by Rob R., the slab is storing way too much heat and releasing it when the thermostat is satisified.
Radiant systems are best when they react slowly and that is done with lower water temperatures.