Outdoor Reset Control

If you have ever heard the term "Outdoor reset controls" you are probably asking yourself "what the heck does that mean"? Sorry to say, it doesn't mean you can set the temperature to be 80° with puffy clouds and a light breeze! What it actually is, is a control added to or coming equipped on a hot water boiler system that changes the boiling temperature based on the actual outdoor temperature at that time. Buildings lose heat faster in very cold weather and slower in warmer weather. If you have a boiler with a fixed BTU rating and no Outdoor reset, you are wasting fuel. Most of the time ( under 5% all heating season) the boiler in your house is burning too much fuel to heat the space. The radiators just can't get rid of the heat that the boiler produced, and any excess energy built up in the boiler is lost out of the chimney. Standard efficiency boilers with an outdoor reset control added to it or new boilers coming equipped with it, allow you to match your heat loss, therefore saving fuel. Usually 10-30%. Now, with cast-iron boilers you have to be careful not to run them too cool or that will cause condensation inside the flame chamber, causing premature boiler failure. Today's modern stainless steel modulating/condensing boilers can be run as low as you can possibly get them to heat the house. In fact, we try to design our systems where 140°F (180o has been the industry standard for 50 yrs) will be the maximum temperature, therefore maximizing fuel-efficiency and occupant comfort.