So I had a contractor put in a new circulator last season. Its a honeywell PC3F. I tried turning my heater on for the first time this season and the relief valve blew. I tried replacing that and the new one blew. This has never happened before. so I wonder if it has something to do with what the contractor did. He also added a small expansion tank to the unit and routed water away from the old expansion tank which rotted out. The hot water does not reach the radiators.
This is a long shot but could the contractor have installed the circulator backwards? I noticed the writing on the front of the device is upside down and I don't think it was meant to be.