Convert Vaughn S35TPP indirect DHW tank to Buffer tank for microzone hydronic baseboard

REMIXME

Thinking of changing to electric standalone DHW and want to use my existing Vaughn S35TPP as a buffer tank to solve my NG boiler shortcycling due to my microzones. ( It is hard to get my zones above 120ft runs with 20ft baseboard per zone.) But can this work ? I ask because I noticed Buffer tank diagrams show one pipe goes to BOTTOM of buffer tanks but Vaughn has all piping on TOP.

REMIXME

After reviewing all the threads I can find here on buffer tanks, I am quitting this idea. Seems like I will be forced to change the zones to make bigger loops. Very grateful for all of the discussions here over the years. Was having trouble with the Search function last week, but it working great today !

EBEBRATT-Ed

What is the load on your zones and how many of them? Don't toss the Vaughn yet. It may not be as ideal as a buffer tank but it will probably work. How is your system piped?

REMIXME

About 11,500btu per zone. 5 zones plus the indirect Vaughn at the moment. System piping needs changed, and has zone valves with one pump. Will add at least one pump, and upsize the pex. This is on this system (which SHOULD be primary/secondary but is not really, and must be corrected.) Thanks for looking.
TMI here: https://forum.heatinghelp.com/discussion/184041/wise-eyes-needed-puzzler-whats-wrong-with-this-picture-hydronic-baseboard#latest

EBEBRATT-Ed

@REMIXME

I would put the Vaughn in as a buffer. You already own it. The connections on the Vaughn may not be large enough to take the full boiler flow. You could hook the Vaughn to the boiler supply and return and just pump water through the Vaughn with a separate pump when any of the other zones call for heat

REMIXME

That is helpful to hear, thx Ed. The Vaughn has 3/4" connects but it will be large improvement so might work ( with the extra pump and new close to boiler/before zones/ direct piping 180* water in/out of boiler to the Vaughn coil). then I hope to connect hot water output off Vaughn to a new electric dhw tank to hold the 120 * water.

It is small DHW needs for just 1-2 people, little hot water. Hope this will keep boiler happier when just one zone calls.

Just getting all these ideas together in my head before the next on-site consult with a pro (the fifth try in 16 years). May have found someone good, so cross yer fingers for me !

Really appreciate your time and all of the great threads discussions ! Just got my copy of Modern Hydronic Heating (J.S. 3rd edition) in the mail. Quite a theory Read and your help in real world on the ground Practice is invaluable.

-- Del

Ctoilman

I would think about some sort of control configuration that would group the zones for a heat call all at once.

REMIXME

Such a great idea !! More zones on, better flow thru boiler, if am understanding right.

Derheatmeister

Tekmar makes controls that are able to perform "Zone Synchronisation" based on PID .

psb75

Change your DHW to a heat-pump water heater--not a regular stand-alone electric resistance tank water heater.

REMIXME

Considering a heat pump water heater, but need a budget reliable simple one... would that be the Rheem, or are there other ones to look at that you recommend ? Thanks for the reminder @psb75