Proving flame is an important part of the gas firing sequence. Without proof of flame, you risk dumping unspent gas into the heat exchanger, resulting in an explosion. There are many ways to “prove flame,” but we are focusing on the flame sensing rod (flame rectification) method here. Here are the facts: Flame sensing rods, […]

Service valves are so basic, and we see them with such regularity that we can miss them altogether. Before I give the tips, I want to address the tech who tells the customer it was “probably the service valve” or “the caps were loose” as a plausible reason for a leak without actually making a […]

Have you ever seen a low-voltage transformer like the one shown above? It has multiple input (primary) taps for a good reason. It is common to find three-phase and single-phase equipment rated to operate on both 240v and 208v power. That is because three-phase power can either be 208v leg to leg when the building […]