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Motorized Valve Actuator (MVA), four-wire
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MANUALS (3)
Product Highlights
Description
Note: The MVA is not compatible with the Wirsbo Genius control system.
Specs
| Application: | Zoning |
|---|---|
| Voltage: | 24V |
| Operating Range: | 24V +/- 10% VAC |
| Max Close-Off PSI: | 17 psi/39.2 feet of head |
| Wiring: | Four-Wire |
| Type: | Motorized |
| Max Number of Actuators: | 6 MVAs (50VA transformer) 9 MVAs (75VA transformer) 12 MVAs (100VA transformer) |
| Used With: | TruFLOW Manifolds |
| Current Draw Range: | 0.29 Amps |
Questions?
Product Reviews
Most Liked Positive Review
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Wirsbo MVA have good track record
Most Liked Negative Review
Easy to install
Be prepared to replace every 2-3 years
MVA for Radiant Heating
they work like they are supposed to
Very good product.
Quick acting
Valve Actuator
Fills the bill.
Just like picture, different color is al
Purchase process was great...
PexSupply exceeded ecpectations.
Product Q&A
14 QuestionsQ: Hi- So I think a couple of these are shot on my setup, the thermostat calls for heat and the actuators don't do anything. My question is, can I unscrew them and put a new one one without water leaking out? like some others - mine are mounted upside down...
Asked by Nancy the Newbie 13 years ago
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I can't get the "simply answer" icon to respond, but yes, you can unscrew the MVA without causing a leak. The valve which the MVA attaches to will remain closed. sam
No water leaked out when I replaced mine. The valves are sealed, even when you manually push down (up in your case I guess) on the valve pin (like the actuator would do) to open it with the flat portion of a flat blade screwdriver, no water came out. I have about 16 actuators and only a couple have gone bad after 10 years, I would make sure you are getting voltage to them before you start replacing. I've had more trouble with the internal switch in the actuators going bad and not completing the circuit back to the circulating pump than the actual actuator not plunging. Good luck.
Yes. The valve is always closed. The actuator pushes it open.
I bought a couple of these and yes I replaced them without any water coming out. However, it might depend on your system. Might want to have the boiler off when attempting to be sure.
Q: I have a Wirsbo Valve Actuator part number A 4024F NC that has failed and I need to replace it. Is this one the replacement part now?
Asked by Brian 13 years ago
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It sure looks like the same actuators in my Wirsbo system.
After 7-8 years & 2 failures, I've changed my original MVAs to p/n A3020522 which works great with my system. Sam Oriental, NC, US
Q: I would like to controll 2 MVA with 1 thermostat is this possiable if so How
Asked by Anonymous 14 years ago
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Verified Reply- PexSupply StaffIt is possible. You would need to tie (or "piggyback") the wires of the two actuators together and plug them into the same port on your zone control.
Q: I need to replace my Wirsbo MVA. The one I have is green in color part # A3020522. Isee the one on your web site is blue in color with the same part #is this the same part?
Asked by Buddy 14 years ago
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We replaced our original green-covered valves with the blue ones about 18 months ago. They are the same in function & are doing fine. Sam Myers Oriental, NC
Yes it is the same one. Change in color might be the updated model.
I've replaced several, they've gone from green to blue now. They appear to be the same......Lake City, MI
I have replaced several of the Wirsbo MVA (green) controllers with the newer model that is blue in color. The replacement was easy and the new units functioned equally as well as the original.
I just replaced my green colored MVA with Blue colored ones and they seem to be exactly the same and working fine.
Yes.
I believe that it is the same - we replaced several and these have worked great ! .
Q: Is there an approved solution for mounting actuators upside down? The manifold in my house has the fittings mounted that way, and it would be very difficult to change it.
Asked by 14 years ago
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Verified Reply- PexSupply StaffWe don't see how you'd be able to mount the actuators upside down without having water running over the actuators (which is a safety hazard).
Q: what happens if the actuators are installed upside down
Asked by johnnymack 14 years ago
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Verified Reply- PexSupply StaffThe actuators would still work, but installing them upside down is not recommended. Water should never run on top of electric because any leaks could result in a fire.
The manual says nothing about what happens when the MVA is installed upside down, but explicitly says to only install it on it's side or upright. Seeing as it is motorized, it seems it will not function properly and will degrade the time in which it lasts.
Q: I have a number of these valves in my residence that have the Wirsbro name on them, but otherwise functionally identical. I have had to open every one of them due to corrosion on the contacts of the end-switch contacts. It makes just enough contact to light the LED in the Zone controller, but not enough to trigger the remote end-switch at the pump controller. (You can actually see the LED in the zone controller glowing slightly dimmer.) Is there any upgrade to a better switch inside these valves? Although the switches are rivited to the chassis, I have been able to drill out the rivit and open the small switch in order to clean the contacts. Happens about every other year. Anyone have any ideas?
Asked by Dennis 15 years ago
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Verified Reply- PexSupply StaffWe have never heard of this issue before. We know that you have to make sure your transformer is strong enough to power all your units. If you do not have enough power, it will cause the units not to work correctly and the control boards to go dim.
I have the same problem. Good switches read close to 0 ohms when closed. Bad switches read between 5K and 30K. At least 3 out of 5 in my system are bad right now.
Q: I seem to have about 3 of these MVAs fail each year. They seem to snap back at the base so that the threads are still on the pipe but the main body of the MVA is hanging back off the pipe...
Asked by Keith 15 years ago
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Verified Reply- PexSupply StaffWe recommend that you follow the directions when installing the actuators. You can over-tighten the actuator and cause it to snap.
Q: Is there any functional difference between A3020522 and SKU:MZV520-RP?
Asked by Chuck 15 years ago
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Verified Reply- PexSupply StaffThere is no functional difference between the two actuators.
Q: Are these MVA's the correct replacement parts for the old Wirsbo thermal telestats (installed 1995). The screw on adaptor on these MVA's looks the same as the old telestats adaptor. Also do I need to drain any or all of the water out of my system before removing the old telestats off of the mainfold and can a 3 valve mainifold still work with 1 broken telestat removed from the manifold as I get no flow through the broken telestat?
Asked by Vic 15 years ago
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Verified Reply- PexSupply StaffIf your manifold is from 1995, it more than likely has 'Wirsbo' stamped on the cast brass body. If this is so, then you can replace with either the A3020522 Motorized Valve Actuator or the A3010522 Thermal Actuator. You will need to drain the water out of your system.
They are direct repacement parts for the old Wirsbo telestats.You do not have to drain any water from system.Just disconnect old telestat and install new one. The system will work with the broken telestat removed. Water will flow when the working telestats call for heat. You will not be able to contol the temperture of the disconnected zone but it will work when the other zone do.