Moved into a house with Radiant heating running pipes in the floorboards. There are two zones: upstairs and downstairs. We had the heating loops looked at and completely redone (when we moved in, there was no pressure release tank, and a strange loop setup) because the heater would throw low pressure errors and shut itself off. That’s resolved with the new setup.
The issue is the upstairs doesn’t seem to heat up. Downstairs I can feel hot spots when the heat is on, and in general, the temperature eventually rises to the set temp downstairs. Upstairs though, the heat can be set and pumping for two hours and nothing seems to happen. At the piping, the temperature going into that zone is hot (130 F) and returns fairly hot too (~110 F). Meanwhile, downstairs the return water is much cooler (~85 F). I just don’t see why the upstairs doesn’t get warm. The only think I can think of is that the pipes are not routed correctly somehow. Looking for suggestions or someone who knows the issue.