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Wirsbo Valve Actuators are breaking !!

Hi All,
We have a boiler with a radiant floor (and forced air) setup which includes a header with 7 Wirsbo Motorized Valve Actuators (A3020522) to control the zones. The zone supply temp is controlled with a 3 way mixer, running at about 120 deg.

The problem is, this system is only 3 years old and I already have 2 broken actuators (sitting here in pieces in front of me as I type..) Both seem to be plastic fatigue (?). The first one broke where the plastic legs join the brass threaded fitting/attachment to the valve. The allowed the whole actuator to lean over and flop about.. failing to control the valve. The second unit failed internally, where the actuator control frame is attached to the plastic body/housing. It is attached with plastic standoffs, and these have sheered off allowing the control frame to float inside of the housing (again, no valve control).

Is this just total lack of quality control ??

Could they have been installed wrong (sure looks straight forward..) ??

Sidenote: If ya need to take one of these apart..
1) remove the motor cover (round cover)
2) remove small screw and cover plate below motor
3) CAREFULLY remove the 2 trapped rods holding the
motor in place (push down and towards motor,
watch for flying rod in eyeball)
4) remove motor by pulling straight out
5) pull up and straighten 2 flat clips that were under
motor, remove face plate from other side


  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542

    has a replacement program for these. Their supplier had a problem...

    Contact your Wirsbo rep for replacement information.

  • Dave Carpentier_2
    Dave Carpentier_2 Member Posts: 4

    Thanks for the quick reply, Mark.

    The last time I approached the rep about the first failure, he suggested i buy a replacement (which I did.. $80 cdn) and then he'd try to submit the old one to Wirsbo. The impression I got at the time, was that these were 2 or 3 yrs old, and probably out of warranty. I just bother following thru, as it was just one unit (at the time.. lol) If I have 5 more failures coming, Id like to get this solved ASAP, of course..
    Would you have any more detail on the replacement program ??

    Thanks for your help..

  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542

    Fell asleep at the keyboard. ALmost wrecked my computer.... Contact Tim Doran at Wirsbo in Apple Valley Minnesota 800-321-4739

  • Tim Doran_2
    Tim Doran_2 Member Posts: 131

    Sorry guys, the cdn $$$ tells me that you are north of the border and that means that you will need to speak with my Canadian colleagues as their warranties and program may differ or may be handled in a different way than we do down here. 888-994-7726

    Tim D.
  • Dave Carpentier_2
    Dave Carpentier_2 Member Posts: 4
    Thanks Guys..

    Appreciate the responses..

    I stopped by the dealer/wholesaler today, and the rep indicated that he was getting quite a few of these units breaking. It sounded like his contact (district Wirsbo rep ?) was not aware of the problem. Ill furnish him/them with the H021403-01 number and see what comes up.

    One of my units is dated 0501 (broken base) and the other is 0801 (broken plastic internally).

    Ill keep ya's posted.

  • Glen
    Glen Member Posts: 855

    over tightening is a leading cause of failure. The pointer indicates both an installed but closed position and then the open position. do not tighten fully down.
  • Dave Carpentier_2
    Dave Carpentier_2 Member Posts: 4

    On these units, it's stated pretty clearly to index the pointer over the green dot at install. Good point tho.. i wonder if some homeowners have thought "geeze these little things are too loose" and tightened them down firm ?

    On another note though.. the valve itself is spring-loaded "on" (up), and when we screw the MVA down, we're spring-loading (internal springs in the MVA) the valve "off" (down). So, the only work the motor has to do is push against its own internal springs with a pressure slightly more than the difference between the 2 spring systems. The motor itself doesnt really affect the housing (breakage) so much as the pretty impressive spring tensions on it. Screwing one down tight would increase the standing spring pressure on the unit, Id think.
  • Roadflash
    Roadflash Member Posts: 1
    Breaking Wirsbo MVAs

    I have a 16 year old house with multiple radiant zones, 20, that the actuators are failing. The owner claims that he has been replacing them for a total of 30 changeouts. He keeps a spare box of parts of valves, actuators, and complete assemblies on hand. He is now renting the place and I am getting the calls at 2 AM when there is too much heat or too little. The failures are in the MVAs with every possible problem. I think that they are installed on the supply side, but need to check. Hard to believe that the problems are so extensive without hearing about a better solution. Heard about recalls, but need a more reliable fix. Caleffi, newer manifolds, any other solutions would be appreciated. thx
  • Steve Whitbeck
    Steve Whitbeck Member Posts: 669

    The new power heads are a MUCH better design. All of the companies are using the same power head now with a different adapter to fit their manifold. Just never mount the manifold with the tubes coming off of the top. The dirt builds up in the stem seal and distroys the O ring seal.
  • Hammermawl
    Hammermawl Member Posts: 1
    Were these also marketed and sold under the Burnham Boiler name

    Mine crapped the bed also I have 3 and 2 totally broke and fell off the manifold they are Burnham but a little research and I am pretty sure they were not made by Burnham.

    They are 10 years old they are not for primary heat but secondary pex under tile in bathrooms and laundry room.

    What is a good plug and play replacement.


This discussion has been closed.