The best part about owning a boiler is not having to repair it, and hiring somebody else to come in a fix it up. What if there was an easier way though? What if this way happened to be self-repair or a troubleshooting if you will. I think it is unbelievably important to go through a basic checklist and troubleshoot as much as you sanely can. Ensuring that you will get your money's worth for the plumber to even show up. Most people deal with big time plumbing companies. This can lead to oversized bills for things like showing up, and checking out the issue.
