Indirect water heater control solution needed!’

[HeatFarmer]

I’ve finally got my Effecta Smart 55 system up and running. I’ve done serval small half load burns, but pushing temps in storage much above 100F. I insulated the tanks yesterday so today I’m doing a full burn.

My system: two turbomax 23 indirect water heaters, 800 gal storage, primary radiant loop—for now insulated, goes outside between two buildings, a radiant slab loop and a panel radiator loop

I have the primary loop set to run continuously at full temp when outside is below 50*
The two IWH are powered to heat to 180 and 195. I had to turn them off today because the boiler temp was pushing 212 and the flow temp was 110. With them off, of course, things calmed down and storage absorbed more heat. I then turned one back on at a time to bring up to temp.
The primary heating loop is off as it’s 64F!
I’m wondering if the two IWH loops are taking up too much flow, and how to solve that. The pumps stress running at 4.5 and 8gpm. And how can I set them to turn on when flow is over 175*, say, and run till setpoint. Is that a simple aquastat on the main pipe? I’m also not sure I want them running at the same time…. The hotter tank is for use in a milk pasteurizer. It’s used 3x/wk. The other needs to proved 170* water several times a day.

I’ve plumbed the system per Tarm and Idonics guides.
For now I need an inexpensive solutions. This system hasn’t been cheap to get this far and I didn’t get to use it at all last year. Eventually I’ll let the effecta do some of the control.

 

[gthomas785]

It looks like you've got ball valves everywhere so could you just try partially closing one to the indirect tank to reduce the flow? Seems like what you are experiencing would only be an issue while recovering after you completely used up all your hot water.

I cant really tell how your piping is laid out but if you have a secondary circ creating much more flow than your primary circulator you are going to have imbalance issues