Heat Timer Corporation

Because of regulations put in place after the outbreak of legionnaire’s disease in the 90’s, installation of Domestic Hot Water (DHW) systems were changed for the sake of public safety.  All DHW systems, whether storage based or tankless, must now meet the conflicting requirements of holding DHW at a minimum of 140°F (60°C) to comply with such standards as OSHA Technical Manual Section 3 Chapter 7, to combat Legionella growth, while delivering hot water at a temperature that prevents scalding injuries in sinks and other fixtures. For decades, commercial plumbing installers have embraced a 3 way mixing valve or “tempering valve” as the perfect solution to the dilemma. Early tempering valves were controlled manually with fixed setpoints, but in 2020 we have evolved to using motorized valves under the direction of a standalone electronic control station that adds flexibility, reduces energy use, provides alerts and alarms, and generally improves the safety of any domestic hot

We all know the importance of rotating our tires. On most vehicles, tire wear is uneven front to back, so manufacturers recommend tire rotation at every oil change. Tire rotation enables all four tires to wear evenly, so they can all be replaced at once when they are worn. Unfortunately, even with proper maintenance, a tire will still fail occasionally due to a stray nail or a winter pothole. That is why most cars still carry a spare tire that can be swapped in for the flat tire, preventing you from being stranded far from home late at night. It turns out that a similar situation exists for building managers looking to the health and efficiency of their hydronic heating systems. Much like our tire rotation analology, failure to rotate the hydronic load across the system can lead to early pump failure and unnecessary replacement expenses. What is a Pump Sequence Control? A pump lead-lag (PLL) controller (also called a pump sequence controller) can balance the run ti