I have a Peerless boiler and today woke up to it not heating the water. The water definitely feels like it is circulating through the pipes, but the water temp isn't getting over 60 degrees. We had it serviced about a year and a half ago and the tech had send, I believe at least, that the burner was getting old. I believe that this was an easy repair if that is my issue. What can I check myself and how do I check it before I have a tech come out and look at it?