I call this job a refit because the existing system in the boiler room was for lack of better words, an 'abortion'. There was parts of the old coal system still in service. The gas boiler was on its last leg. Someone added a feed tank that was bigger than the boiler. There were pipe patches all over the piping. Jobs like that are best suited by a complete do over. That was what we did in this house. The boiler was replaced with a SlantFin Galaxy. The pumped return was turned back into a gravity return. We added serious main venting to the system. The owner who is 84 and barely had any heat last winter has plenty of heat now. She also said that the system is significantly quieter since we did our work.