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Plate HX flow questions, low boiler return temps

warno
warno Member Posts: 229
edited October 2016 in THE MAIN WALL
I have recently put in a 750 gallon storage system for this winter and I've started heating the storage now. I'm heating my storage through a plate HX via my boiler. I'm getting really low return temps going back to my boiler. I added a diverter valve to switch to my heat dump zone if the storage was charged and boiler was still firing. wondering if my diverter valve is adding way too much head to the boiler line. I'm running a bell and gossett nrf36 circ pumping away from my boiler. it goes through a 1" butt weld 90, and a 1" copper 45 sweat elbow then my diverter. There's about 20 feet of 1" pex line and about 3 feet of 1" copper between the boiler and diverter. This is just the supply side the return side goes through a tee, 45 copper, 45 black iron, then a caleffi thermomix valve. With the same amount of piping as supply.

This is my diverter valve
http://www.supplyhouse.com/Caleffi-Z300637-Z-One-1-Sweat-3-Way-Diverting-Brass-Valve-Body-20-PSI-7-5-Cv

My attachments are:
Piping layout
Boiler temp in at hx
Boiler temp out at hx
Storage temp in at HX
Storage temp out at HX

Is it possible my diverter is slowing the boiler flow to much?

Comments

  • warno
    warno Member Posts: 229
    I understand the tanks will take awhile to heat but a delta t of 50 degrees seemed huge to me. As the heating progressed to return line did get warmer but it just had me wondering if that diverter valve would have been better replaced with a tee and 2 way valve above it with the supply flowing from the center port of the tee to the HX.

    The budget doesn't have a new pump in the future for me so I'm pretty stuck with what I have. Should I just run it for now and get everything up to temp and see how the DTs are after that?
  • warno
    warno Member Posts: 229
    Ok I'll try choking the tank side back until things get warmed up closer to target temp.