Have an interesting problem. When the thermostat is turned off, hot water will continue to occasionally flow through the radiators on one floor. We've had the thermostat turned off now for a few days, and the radiators are still hot. The boiler kicks off every now and then, and I notice that the radiators get hotter. We have two circuits, one for each floor connected to the same oil buring furnace. On the outlet from the furnace there is an expansion tank and then split going to each floor. Each split has a Taco SwetChek valve. Any idea what I should look for? Thanks for any help.
