Hydronic Heating On Line

Follow on from my last post, I got a surprise the next morning after turning the temperature setting up. The manifold temp had dropped to about 40!  So the heat pump doesn't just run at the set point, it incrementally boosts the water by a few degrees while the floor is sucking the heat out as quickly as it's fed. By today, Friday morning, the floor had come up to around 55-57 with manifold temp of 60. This evening early it was at 61 and 65. I decided to shut off the upstairs loops and turned the pump to high which soon brought the manifold up to 70 and the floor is mid 60's. it's almost comfy in here but a test will be next week when the cold snap may hit us. We still don't have attic or crawl space insulation which will make a big difference.