Whether it’s a boiler or a furnace, over the years there have been major improvements to the equipment you use to heat your home. One important factor in making today’s oil heating equipment so remarkably safe and efficient has been the proven reliability of modern oil heating controls.
A wide range of limit controls, thermostats and switching relays are used in the operation of oil heat systems. And they have become more accurate and sophisticated with the introduction of more technologically advanced equipment.
Here’s a brief overview of some of the controls to help you better understand how your oil heat system works. Let’s start with the device that gets all the gears in the motion whenever your home needs heat.
The thermostat is the control that gets all of the other controls on an oil heat system going. When heat is needed, the thermostat starts the burner through the primary control and an electrical circuit.
Today, many people are using a smart thermostat in their oil-heated homes. A Wi-Fi enabled thermostat allows you to view and change temperature settings from anywhere, thanks to your smartphone.
Once the smart thermostat gets installed, you register it online. This enables access from any location. If you’re away from home, you can use your phone to adjust the temperature setting so your home is at the perfect temperature when you return. You can also monitor the temperature in your home when you’re away on vacation and take action if you detect a problem.
Limit controls on oil heating systems regulate warm air, water temperature and pressure control. There are two categories: high limit/safety controls and low limit/operating controls.
High limit/safety controls: These controls act as safeguards to prevent overheating. They will turn off the burner if temperatures become too high in the furnace or boiler, or if the pressure in a steam boiler rises to an unsafe level.
Low limit/operating controls: These controls start and stop the burner on a signal from the thermostat or aquastat (a device that controls water temperature).
Primary controls monitor the oil burner’s flame. Solid-state controls and advanced microprocessor-based controls are very accurate. Primary controls also have a reset button that allows you to restart your oil burner (when the power comes back on after an outage, for example).
Additional protection circuits, such as the cad cell (cadmium sulfide photocell sensors) were added to oil heat systems in the early 1970s. A cad cell, which is usually mounted on the burner, uses its photo cell “eye” to send a shutdown message to the primary control board if it cannot “see” the burner’s flame anymore.
There are usually two switches that will cut off power to the burner. A red emergency switch is typically located at the top of the basement stairs. If the heating system is located in a utility room, look for the emergency switch near the room’s entrance. A second burner power switch is often found on or near the heating system.
You can read more about oil furnaces and oil boilers here.