[mark3681]

By the way, this is very similar to what I have. The system does not supply hot water to any faucets (as shown in the pic). Hot water to the faucets is provided by a standard gas water heater.

[eastforker]

Good diagram. Check that flow control valve for an onstruction, also check for settlement in the expansion tank.What size pipe is used going to the radiators?Also, check water temperature coming out of boiler to see if the water is being heated to operating range.