I have a hot water heating system. It's a single loop in a ranch home. The ground floor is about 1500 square feet. When the oil furnace turns on, the first few radiators in the loop get warm, but the ending radiators barely get any heat. My thermostat is set to 68F.
If I push the heat up to 73F, then the ending radiators will get warm. I was thinking maybe there was some air trapped in the end radiators, but when I opened their bleed valve, nothing came out, not even water. This was while the hot water was circulating in the system.
I'm wondering if anyone has any ideas as to:
Why the end radiator didn't spurt any water out when I opened the bleeder valve - could it just be jammed up, or is there not enough pressure in the system? My furnace says pressure is at 15 psi.
Is 68F simply too low a temp to expect hot water to get to the final radiator?