Heater doesn't come on?
The electronic ignition system in a gas furnace is a modern development that
allows more reliable performance than standing pilot furnaces, provides energy savings and contributes to better furnace efficiency (AFUE). With a standing pilot, found most commonly on older low
efficiency furnaces (55% to 65% AFUE is not uncommon), a small gas flame is
always burning and is known in the lexicon of American home repair as a "pilot
light". The problem with this type of "analog" ignition is that it wastes energy
by constantly burning gas and can sometimes be unreliable.
These issues have led to the development of electronic ignition
systems for mid to high efficiency furnaces that exceed the U.S. government's
established minimum AFUE rating of 78%. The electronic ignition occurs typically
in one of two ways:
Intermittent Pilot, or
Hot Surface Ignition
The intermittent pilot system uses an electronically controlled high
voltage electrical spark to ignite the gas pilot and then subsequently the main
burners, when the thermostat
calls for heat.
The hot surface ignition system uses an electronically controlled
resistance heating element not unlike a light bulb filament (and shown in the
photo above), to ignite the gas burner.
It is important to understand some of the other components of a modern
furnace that you will encounter depending on the type of high efficiency furnace
you have. Why? Because they can also come into play in repairing an electronic
ignition furnace when it won't run properly. Let's take a quick review of the
types of furnace designs and components found in high efficiency furnaces using
Nov 14, 2010 |
Goodman GMS90703BXA Heater