One pump is for 3 ways mixing valve to go to supply (in floor) and automatically regulate the water temperature in the secondary circuit. You do need TWO pumps when it comes to tankless heater...
NP... believe me this setup kicks in the *** as it was designed to work better with tankless heater as I see how it runs its too sickie.. I dont believe in using water heater and boiler setup on the tankless heater and its not really recommended but people did it.... hope they r happy with it...
From Ontario & it runs 10-12 minutes every 3 hours if I keep opening door not sure how often it runs yet still new to this setup I built. Not sure if this has anything to do with foam insulation too as its sprayed full in foam insulation.(walls/ceilling and rim joinsts). Hate to say this but my...
As you see only the tankless heater temp control is there. (NEVER put the thermostat close to the hydronic system as it gets hotter unlikely the room temperature. I've seen a lot of people using boiler hydronic setup with the tankless which makes a short life on the tankless heater.
See how...