Were it me, and I am not suggesting the OP could do this.....
I would manually adjust the the 3-port valve to the CH position, then wire pump and boiler to a plug, then by setting the boiler's flow stat, I would have heat. That assumes the boiler controls have not failed.
I would manually adjust the the 3-port valve to the CH position, then wire pump and boiler to a plug, then by setting the boiler's flow stat, I would have heat. That assumes the boiler controls have not failed.
