While trying to get a circulation pump going on my hot water heat system, I noticed the valve motor ( Synchrono Brand) was hot to the touch even though there was cold water inside the valve and plumbing.. I changed it out for another. It got hot as well. When given the command to open it works against some springs and keeps the springs tight until the valve is given the command to close. While it’s open, even with cold water in the system, it heats up. Is the heat normal? Of course once the boiler water gets there everything is hot. Here are some pics. They may be familiar to boiler owners.
PS, got the feed pump going by turning the power off to the electronic thermostat and pump relay and re-starting. Too many darn electronic gizmos.