Wirsbo- One room no heat

Hi-

I have 3 Wirsbo zones at my house and one of them just does not heat up. The thermostat says on, the correct lights are on the Wirsbo controller, but no heat. Do I have some clogged Pex, or does one of the valves need to be bled? (The other two rooms heat up just fine.)

Many of the Wirsbo zone valves have an indicator on it, showing if it is opened or closed. What does yours indicate? If it is opened and the pump is on and it is still cold, I suppose it could be air. If the controller is not actually operating the valve, you can manually open it by screwing it onto the manifold further. See if that provides heat in that zone. The controller has an end switch that is supposed to start the circulating pump if any one or more of the zones is calling for heat. It could be defective. Let us know what you find and one of the pros may have some other ideas.

heat

If it does not heat then there is no circulation. No circulation would be because of a defective valve, air in the line, or a "pinched" line. The first two can be corrected either by repairing/replacing the valve or purging the line. The third problem is almost impossible to find or repair. If you can purge the line, then it is not a pinched/plugged line problem, but if you do not get any flow when you open the purge cock, then it is a bad line. One other possibility if the grid was installed with more than one loop/circuit is if both ends of the circuits are connected to the same manifold.