Manifold Actuators Motorized vs. Thermal

johntrhodes81

I am trying to find motorized valve actuators to replace thermal actuators on a Mr. Pex Manifold. Motorized actuators are much quicker acting than thermal actuators. I am having great difficulty finding them for any brand. Am I the only one that wants motorized vs thermal? The only one I have found so far are these Honeywell units that I might see if I can adapt. https://customer.honeywell.com/en-US/Pages/Category.aspx?cat=HonECC%20Catalog&category=MZV+Series+Replacement+Parts&catpath=1.2.2.17.22

Thoughts?
John

Zman

How long are thermal ones taking? I have never timed one but it seems like they take a minute or so. The never seemed like a problem to me.
I have used the Honeywell motorized ones on a manifold similar to yours with no issues.

hot_rod

What's the hurry? 2- 3 minutes to open typically, end switch may make about a minute and a half into power up.

You may find a motorized that fits the thread, Honeywell/ Sparco is still around, but the pin stroke may screw you up. If it is not exactly the same travel it could stay partially open, or not open enough.

The open time for thermal actuators depends a bit on the temperature they start from. In a cold space it will take longer to open.

Also most all brands now offer a low power consumption version, 250mA compared to the typical 750- 800mA. So the low current versions will take twice as long to fully open, but you can put more per transformer.

Bob Bona_4

I've found thermals last much much longer than motorized.

Hilly

I was 5 minutes on initial startup last week with some of the new uponors.

Bob Bona_4

Agree, it's like waiting for water to boil. I'll take it over constant motor/end switch/valve body failures

hot_rod

Hilly said:

I was 5 minutes on initial startup last week with some of the new uponors.

How long for end switch contact and some flow? It should be a few minutes to get some flow going, 5-6 for full open.

Hilly

I didn't time the end switch. But it definitely came on much sooner. I know that for sure because I could see and hear the boiler running from where I was. And it did feel like watching paint dry waiting for the blue ring to fully open. I almost wish they had some sort of orange/yellow/green lighting to show working, end switch and open. It's fine in new construction but I could see troubleshooting as a real butt pain.

Dave H_2

when the thermals are brand new, it may seem like a terribly long time due to the first time they are initiated. the ring is partially "lifted" in manufacturing to allow ease of install on the manifold. After the first time, they will respond much faster.

If you need lights, use the ZCM (yellow when call for heat, red when end switch makes for each individual zone)from Uponor or the Taco ZVC (same light color sequence)

Dave H.

Hilly

Good points Dave. I never thought about checking the speed after the first time. And you are right about the ZVC. It's probable smart for the head to be keep simple and cheap anyway. Too many parts means too mean potentials.

johntrhodes81

Lot of good points here. Thanks.
John