zone valve versus flo check valve...

Jim_95

Is it possiple not to get enough BTU's through a zone valve due to rduced port zize?

ronyD

zone valve versus flo check valve...

Which option is best for a Gas boiler, 3 zone installation with domestic hot water heater.
1. zone valve per circulator with taco 4-zone with priority controller.
2. one circulator, zone valves for each zone with taco 4-zone with priority controller.
3. flow check valve per circulator (can use taco's circulator with IFC option?).

Option 3 Eliminates need for zone valves and zone valve controller. How do you setup DHW priority without a controller?

Ron Schroeder

ronyd

I would use the Taco ZVC403 and wire it as in page 31 http://www.taco-hvac.com/uploads/FileLibrary/100-9.0.pdf

You want the DHW tank on its own circulator and the Taco control realy makes wiring and trouble shooting the zone valves a snap.

carol_3

I vote for option 2.

ronyD

Carol,

why option 2? Is it wise to have a single point of failure? I was thinking if a circulator or valve fails, still have heat from other zones.

your thoughts are appreciated...

Ron Schroeder

ronyd

with zone valves if the circ fails no heat at all. but if a zone valve fails it can be manually opened and closed for heat to that zone, if a circ zone fails no heat to that zone at all. Just depends on preferance although power consumption is less with zone valves.

ronyD

my other thought was, if I have shutoffs on each side of the circulators, I can service the zone myself. Just go to the local HomeDepot, get a taco circulator off the shelf, and replace it. I'm afraid with one circulator, I'm down until I can get a plumber and/or plumbing supply to purchase. Double Home depot carries large circulators.

But point being, as long as I can open the zone valve manually, I got temporary heat.

My question still is, a circulator for each zone valve or one circulator serving all zone valves?

Ron Schroeder

ronyd

either one circ with zone valves or a circ with checks for each. Also I would check into Grundfos usp 15-58 3 speed circs as you are going to dealing with multiple head losses and this will better cover all your bases.

ronyD

Bruce,
I contractor is specing with one circulator/multiple zone valves, the other specing multiple circulators/multiple zone valves, both using the taco zone controller. Mulitiple circulator approach just overkill, or they just don;t want to determine the proper sizing of using one circulator?

Can;t figure these contractors out. Seems like they want to do things the only way they know, usually word of mouth from other contractors on what they do.

Ron Schroeder

ronyd

Well one circ multiple zones is fine as long as the cic is sized for the highest head zone. I don't understand why one would want both zone valves with cirs on one circut, unless they don't like check valves, now I never put more than three zone valves to a circ but you have threee heat zones and one DHW zone that should be on its own circ.

ronyD

Are zone valves better than using flo check valves?

Ron Schroeder

I think

that the cost oof zone valves are about the same as circs so either or would be the case

Robert O'Brien

Zone and flo checks

In some DHW priority systems, it is possible for the stats to do a heat call and open the zone valves when the DHW circulator is running in priority. Those systems require check valves on both the DHW and heating loops.

ronyD

Bruce,

Not to beat a horse over the head on this issue. But, in priniciple why use zone valves over flo check valves or vice versa?

Paul Fredricks_3

In my experience. zone valves for the heating zones on a common circulator. It's a simple install, and if the circulator goes bad there is usually enough gravity heat through the open zone valves to keep the pipes from freezing. If a zone valve goes bad it can be manually opened until it's repaired.

The domestic water heater, I assume you mean an indirect heater running off the boiler, should have it's own circulator with flow check to assure proper flow and plenty of hot water production.

I have seen a lot of jobs with the circulator/flow check option. It seems that plumbers especially like to go that route. I think it is over kill, unless you have a huge house with need for a lot of flow.