Hydronic Heating not working but the boiler is operating?

A common cause of this can be a “stuck circulation pump”

1. Isolate power to the pump which may be powered through the boiler

2. Isolate the pump from the system using the service valves if fitted

3. Remove the large access screw on the side of the pump housing

!Caution the water released from behind the access screw will be hot if the system has been operating

4. Manually turn the shaft using an Allen key or screw driver

5. Reseat the access screw

6. Turn the service unions to open if fitted


The procedure above should have dislodged any foreign matter impeding the pump impeller operation.
If the pump operation has not been restored contact your local service agent.