Best ,reliable/easy servicing z-valve?

Eric_6

Best reliability would be non-electric zoning with the ECM circulators by Wilo or Grundfos. We spec out Oventrop and Danfoss for as many jobs as possible. For existing systems it may be impossible to switch to these. In this case we spec the 24 vac Caleffi thermal actuators. Have had good luck with them.

All the best,

Eric

Saggs

Any recommendations for an easy servicing reliable zone valve? Seems I'm always changing end switch or motors on the Honeywells? Looking to go to z-valves on an install over pumps to save the HO a little $. Thx

Steve Ebels_3

I like

Belimo and Caleffi are my two favorites and I still have good luck with the old 570 series Taco's with the heat motor actuator drive. The Belimo's can be had in about any configuration or voltage you can imagine. They cost a few more bucks but do hold up much better than the made in who knows where these days Honeywell 8043 series. I wish that Honeywell would do something about the quality and service life of that operator. There are so darn many of the old ones out there that have been on for years and years and given outstanding service that the homeowners really look cross-eyed at me when I tell them I'd like to change brands. If they refuse they usually wind up asking me to switch brands after the 2nd or 3rd HW replacement fails in 5 years time.

Bob Bona_4

Steve

what do you think of the super duper version of the HW ZV's?

Also, I've used the Caleffi's but have wondered what and why they may last longer than the annoying VR403s. Is it less operating stress on the motors? Or better motors?

Inquiring minds want to know!

Steve Ebels_3

Can't comment on that

I haven't used or even seen the SD version honeywell so I really can't speak to that with any authority. Most of the problems with the 8043's seem to be end switches and gear failures from what I see. The motors are usually ticking away yet.
AFA what makes the others hold up better I can't really pinpoint any one thing. I just know that I haven't had much in the line of call backs on the models I mentioned.

Unknown

Taco

Taco... all the way.. However, I do wish they have a dry contact end switch on power head..

hot_rod

heat kills the motors

some brands use a plastic case to minimize the fluid temperature getting to the motor. An aluminum mount plate acts as a heat emitter, between the plastic case and motor, and doesn't rust in chilled water applications.

A well planned ZV would work in chilled fluids, heating, and steam all in one model.

A transmission instead of a stamped sheet metal gear would be good, with a 21:1 reduction to ease the load on the motor.

A good gear train would allow higher close off pressures, like 30 psi at 3.5 Cv. Cv up to 7.5.

A "lost motion" gear allows the transmission to disengage from the valve when it closes. This also takes load off the motor on start up. The motor has a 270 degree rotation before it engages.

Stainless steel shafts and bronze bearings are longer lasting.

An end switch that "makes" when the lever is moved to the open position manually.

A wound, coil spring that is set on every valve with a torque meter so the load on the motor is always spot on.

End switches haunt every ZV manufacturer. These micro switches actually have a min. and max. current rating. When connected to some relay boxes the current draw falls below the switch minimun. When this happens the switch doesn't get enough "wiping" current to keep those small silver points clean. Dirty contact points= high resistence=heat= burned contact points=failure.

One manufacturer is switching to reed switches, hermetically sealed and actuated by a magnet instead of a cam lobe.

This type of switch, like a door alarm switch, has both a low and high current rating, in line with the products out there that get connected to end switches and should be much more reliable.

Motors vary from brand to brand also, depending on the letter indicting temperature tolerance.

A body with a removable brass cap to clean any crud out of the paddle and seat , and a large diameter volute to lower velocity is a good feature.


With more and more ECM delta P pumps on the market I think zone valves will being to be more popular.

hr

Charlie from wmass

I figure if they want to save money pump it. With the IFC pumps Reliable life can make up for the extra piping you need to do. I use the tacos if I am corned into using zone valves. The choice of whats on the wholesaler shelf if the one I install fails makes it hard to go with any thng besides Taco or Honeywell around here.

Plumdog_2

OK........so

Without naming names what brand is it?

Saggs

Are you referring to the old tower style taco's or their newer see-thru plactic housing type?