Hydronic Piping Schematic Modcon Setup

klowden

I posted previously about my hydronic geothermal system.

I am abandoning the heat pump and replacing with a propane Navien condensing unit with small buffer and indirect, outdoor reset.

Is this schematic correct for what I want to do?

Any guidance will be greatly appreciated.

I currently have 5 zones as per my geo post.

hot_rod

looks good, 3 pipe buffer, indirect parallel.

I might move the expansion/ fill closer to the tank. Downstream of the dirtmag

klowden

Thanks. I will make sure to do that.

Kaos

Did you check your fuel costs? Around me propane is close to the same price at resistance heat, if you already have the resistance boiler, might not be worth the complexity.

Buffers are not free. You only need it if you microzone with low mass emitters. If that is mostly heated slab zones, you don't need the buffer.

klowden

I'm at .17/kwh and it is supposed to go up again soon. Propane is currently $2.69/gallon. If we lose power for days like we have in the past I can't run that 16kwh boiler with my 10kw generator. We were left in the cold more than a handful of times over the years when the heat pump conked out and we had zero heat.

hot_rod

here is elec vs lp .17 @ 100% vs 2.69 @ 87%