Water temp loss of 30 degrees I have been heating an old farm house (no insulation) with a 240 gallon Acme(shaver clone) OWB. I have cast iron radiators on the first floor and second floor, pressurized system with HX. I also am heating a shop about 150 feet away. I have 1 inch insulated pex underground. 1 pump to the house, 007, and one 007 pump sending water 150 feet one way, to the 3 radiators in the shop. I bought into the 1 inch theory, as being big enough to make the trip to and from the shop. I only need the temp high enough to keep the water from freezing in the shop. The boiler keeps up fine until the shop calls for heat. Then I get a 30 to 40 degree loss in them at the boiler. The boiler never gets a chance to fully recoup. Then the shop calls for heat again. For some reason my mind keeps thinking that the slower the water comes back to the boiler, the easier it will be to get heated back up to temp. That’s why I only have one pump doing the work. Would another pump on the return at the shop help cure this problem? Or are there any ideas that can help eleviate the huge heat loss in the water? If the shop does not call for heat I can keep up just fine in the house, but when heating both, I am having huge problems, besides blowing through the wood.