Wirsbow manifold

plumberdan38

I've got a manifold similar to this one but older. It's got a wirsbo label instead of upnor. I can't pump water through the zone that it is on in either direction. I turned the flow restrictors counter clockwise all the way. Water comes out the air bleeder on the return. Could the header be plugged up somehow or is it more likely that the lines are kinked in the floor?

Alan (California Radiant) Forbes

Try removing those flow adjusters and see if the pin valves move up and down. It's hard to do with your finger; use a flat screwdriver. They are spring loaded; push down to close the valve and they will spring up when you let go. If they don't move, they might be stuck and you will have to replace the whole manifold since replacement pin valves are no longer available.

How is this manifold controlled? Is there a zone valve or pump that allows flow? It could be that one of these is bad. Going back further, it could be that the zone valve or pump is not getting the signal to turn on. Bad control or thermostat?

plumberdan38

Flow adjusters? On the supply or the return? I believe the pin valves you're talking about are on the return and they do push down and spring back. I haven't taken the manifold apart though so not sure what is happening inside. The flow adjuster is on the supply, correct? And they are adjusted with an allen key, right? I turned them all the way clockwise and counter clockwise with no effect either way. The manifold gets flow via a zone valve. I have already taken it apart and can rule out that it is the problem.

Dave Carpentier

So you have a manifold with multiple actuators? No heat thru any of them ?
Do the actuators show evidence of trying to open ? On the Wirsbo motorized actuator, a little lever moves left and right, on the wax/thermal ones the 'top' lifts up exposing a colour ring when its open. The thermals take a long while to open.
Can you post a photo ?

Mad Dog_2

Yes, Wirsbo/Uponor is a high quality product  but I have seen those pintal 
Valves seize up. .
Mad Dog

hot_rod

On the upper manifold, removing the black cape will allow the valves to be wide open. On the bottom, the Allen screw turns CCW to open. Then you need to purge both loops. If valves are open, and the circ running, it sounds like an air lock in the tubing.

plumberdan38

There are no actuators on the manifold. The black caps are off on both the supply and return and the allen screws are turned all the way CCW. I was using the autofill to try and push water through both loops (the manifold looks just like what is pictured just a slightly older model) simultaneously with the return hose, off of a hose bib, in a bucket. Pressurized the system to house pressure (50psi) so not air locked. I don't think the pin valves have ever been shut so probably not stuck shut. I don't know if this zone has ever worked, the new homeowners don't know either. So the pin valves somehow either plugged or the two loops kinked somewhere, right?

Mad Dog_2

Why would the tubes be kinked? Did something happen?  Unless they went in kinked originally, pex will maintain its shape memory. Was construction recently done that makes you suspect that?  Mad 🐕 Dog 

hot_rod

I doubt it is the manifold. You could unhook the loops from the manifold and try flowing through it. That eliminates everything in the circuit but the tube.

A broken tube in the slab would not flow either, but you would hear the water going in.

A frozen loop presents like a kinked loop😳

plumberdan38

Just grasping at straws. The owners are new so they don't know if it ever worked. I was pressurizing it up to house pressure so it's not broken. It was previously a storage room and for a while the zone valve was locked open because the thermostat was broken and off the wall. So could be frozen. I just hooked up the neighbor zone to the boiler. The two zones don't have doors between them so the one zone should heat the other pretty good. Kitec (pex al pex) pipe feeds the wirsbo header and I've read that the Al of the ketic can cause zinc to leach out of the brass and that could plug up a small passageway.

Alan (California Radiant) Forbes

I have already taken it apart and can rule out that it is the problem.

So, you've taken the zone valve apart, but do you know that it opens when the thermostat calls for heat? And if it is open, does the pump turn on when all the other zones are off?

A picture of the zone valve would help us.

hot_rod

The PAP tube was certainly easier to kink, and it rarely unkinked😏 no amount of pressure will fix that.
I doubt it could sludge up enough to stop flow completely