I attach a picture of our UFH manifold. I am having issues getting any heat out to the zones - it is calling hot water (all stata are triggering the control panel and this in turn is triggering the actuators and drawing hot water from the boiler). Once the heat passes through the thermostat at the head of the manifold I am just not then getting any heat through it and into the floor zones ... the underside of the stat (marked with yellow arrow is hot) but nothing into the manifold.
Wondering if it is air in the pipes? Or some fault on the stat ... unlikely to be a fault on the manifold itself as it is an issue on every zone??
How can I test if it is air? Any ideas welcome!!
