how to control my Superstor45 DHW heater

[zadwit]

I have an EKO-60 that have a large grundfos circ pump that feeds two 500 gallon propane tanks (hot water storage). I "T"d off the main 1-1/2" pipe that feeds the two tanks and run that hot water to the inlet side of a superstor45 water heater. The return line from the superstor45 feeds into the 1-1/2" return pipe from the tanks back to the EKO-60.
This works well with a couple of problems. When the EKO is going and its circ pump if going, the tanks get up to 195(f) the superstor gets to 185(f) internally. I installed a circ pump on the superstor to pull hot water from the tanks, but so far I have not needed it. In order to control the water temp inside the superstor I am having trouble trying to decide what to do.Right now it is HOT, maybe tooooo HOT at 185(f). I was hoping for 140(f) or so.

1) Could I install a zone valve at the superstor45 and control it with the aquastat that came with the superstor45?Set the aquastat to maintain 145(f) internally in the superstor45.
OR
2)Could a B&G;flo control valve be installed in the return line from the superstor45 back to the storage tanks and would that prevent flow from the main feed pipe that supply hot water from the EKO-60 to the storage tanks from heating up the superstor45 ? Then when the superstor internal temp is below 145(f)the aquastat would turn on the circ pump, raise the internal temp to 145(f) and shut of.

I had planned on connecting the superstor45 circ pump to the aquastat that is installed inside the superstor and when the internal DHW gets below 140(f) it would turn the circ pump on, pull hot water from the tanks and heat up the superstor, but the big circ pump on the EKO60 supplys plenty of pressure to force hot water into the superstor.......
Any ideas???? or maybe I should just leave it.....

 

[DaveBP]

Sounds like your "problem" might be easy to turn into an asset. The higher the temp in the Superstor the more heat you have in there to use. If you have kids coming into their teen years you're going to need it.
What you need is a non-electric thermostatic valve on the outlet to your domestic hot water that will mix in cold water to the set temp so it never gets above, say 140F, to your shower even if the water in the Superstor water is much higher.
Usually called tempering valves. They're required by code some places.
I've never used one myself. But then my shower is still outdoors. Year round. New house we're building will, though.

 

[zadwit]

Thanks for the speedy reply! I've had the EKO-60 system up and running for a few months now and it works much better than I anticipated. Ironically, fuel oil prices have come down a bit to around $2.90 a gallon so it is still cheaper to heat with wood.