I want to add a 2 port motorised valve to my C/heat system. is it ok to fix valve on it side as space is tight?

In other words the Motor part of the valve would not be on top of the 2 port valve, but on the side. I want to do this so that I can shut off the water and have my underpowered boiler just pumping heat the the radiators (saving maybe 15000 BTU's which can go to the rads.) Please help if U can Thanks