Zone Indirect Hot Water Heater?

Bernie Riddle_2

Should an indirect HW heater have its own zone? If so should it be a valve or circulator? Thanks!

Unknown

yes

It needs to be it's own zone, unless it is the "reverse indirect" style (coil within a tank of boiler water). Those allow some creative piping and wiring, as they can double as a buffer tank.

Circs vs. zone valves: as long as you know the capacity of the water heater under each, and the load demand, piping size, and boiler size, either one could be acceptable.

Noel

Bernie Riddle_2

thanks Noel!

Ron Schroeder

It's hard to get an indirects RATED capacity with a zone valve but you can probably get "enough" capacity thru one.

On my one home, the indirect gets it's own circ and the flow to it is over two times the flow to all of the other heating zones combined.

Ron

Guy_6

Circulator

My experience with Indirects is that they will perform BEST with their own circulator. When you look at the flow capacity of the indirect, you will see that it almost ALWAYS outnumbers any heat zone (residentially speaking). By allowing a dedicated circ., you will be certain to get the maximum output that the tank can pull from the boiler.
If you do use a Z-V, make sure that it opens fairly quickly, because when a tank's aquastat calls, boiler water delivery time is important.

GW

Rob_32

recent experience

HO here. Same indirect run previously with a zone valve yields MUCH better performance with a dedicated circ. Go circ as these gents suggest.

tk_3

Zone Valve is OK

providing it is full port. Most distributors do not carry them though. So circulator is better for proper flow. Make sure piping is sized correctly as some manufacturers require a larger pipe than the tappings.

Ron Schroeder

It's next to impossible to find a Zone Valve with the appropriate Cv. So far the only one that I found that would flow enough for a Buderus indirect was a 1 1/4" White Rodgers that nobody carried.

Guy_6

Keep in mind

Again, keep in mind that even with a full port Z-V, you will need a large enough circ to provide enough flow for ALL heat zones AND the indirect if they are calling at the same time. Conversely, when only ONE heat zone is calling, that large circ will be moving a large volume of water, literally screaming through that zone. It's a fairly difficult balance to acheive, and if you are going to add a diff. pressure by-pass valves to get around it-well, it would have been easier and possibly cheaper to just give the tank it's own circulator.

Unknown

Or use priority....