one zone wont close

munchkinowner

I have a three zone hydronic infloor system heated by a munchkin boiler.  Zones are controlled by two wirsbo actuators and one uponer actuator.  One of my zones turned on/opened earlier today and has not shut off despite having satisfied the thermostat hours ago.  Thermostat is set at 50 (its a workshop) and room is close to 70 degrees.  pump is running constantly.  Boiler appears to be turning off and on as it should (dependant upon return temperature).  How should I troubleshoot this?  Do I likely need a new actuator?  Is there something I can do manually for the short term to shut down the heat in that room? 



OK so this is what I did.  I disconnected every wire that was associated with that actuator.  First I disconnected the wires (one white one yellow) from the thremostat communicating with that actuator - the actuator stayed open/pump on.  So I discoinnected the other yellow wire and the two red wires associated with that actuator.  That worked for now - the pump is off.  That actuator is still open which I believe means that that room will get heat when another zone calls - that is a good thing.  I have basicly made it a two zone system yes?    Until I can get a new actuator.    Any feedback appreciated. 

Zman

You got it

Your actuator has seized in the open position.The red wires (end switches) are closed telling the boiler to fire. Swap out the valve and you should be all set

Carl

munchkinowner

Thanks

Now tell me this (my ignorance will show here).  If the actuator is seized open should I expect some spillage when I remove it?  I think I know the answer - unscrewing the nut will release the valve and it will close - so no spill - but I would really like to be more confident. 

Zman

No Mess

You can just unscrew the head. The valve is sealed.

Carl

munchkinowner

thanks!

Thanks again Carl!