Gas Units- Just the Facts: Part II- IPI / CPI Systems

IPI / CPI Systems (Electronic Ignition)

There are so many versions of this same system, it would take too long to cover them all. Instead, we will break down the basics of the electronic ignition systems, proper operations and cover some Frequently Asked Questions and Answers as well. This article is designed to educate you about the different pilot ignition systems available, it is not intended to be a user guide, an owner’s manual or to be used as a reference for homeowner repair in any way. Always call a qualified service technician to work on your gas fireplace, failure to adhere to manufacturer specifications can result in an explosion.

diagram2To the left is the pilot assembly in an electronic ignition system fireplace. Instead of a pilot tube, thermocouple and thermopile; there is a pilot hood, a sparker and a flame sensor. Instead of being connected directly to the valve, the signals these components give are directed through a control board called a module. The signal is given from a thermostat or manually to turn the pilot on and the sparker sparks while the flame sensor waits to be “rectified”. Pilot rectification is a when the pilot lights, hits the flame sensor, and the flame sensor sends the signal to the module that it is ok to open the valve and let fuel into the burner.

Unlike a millivolt or, “standing pilot”, system, the electronic ignition systems have 2 modes for the pilot light: IPI and CPI.

IPI (Intermittent Pilot Ignition) is when the pilot light is only lit when the control board gets the call for heat, either from a thermostat or from someone flipping a switch.

CPI (Continuous Pilot Ignition) is when the pilot is lit constantly. While it sounds similar to a standing pilot system, it must be understood that these are two very different processes and it is important to distinguish between them.

Both settings have their pros and cons, and there is a time where using one over the other can be extremely beneficial. However, not understanding how this system works can create unexpected issues. A majority of fireplace manufacturers have replaced the standing pilot systems with these new ones, and there is talk happening to phase millivolt systems out completely.

Frequently Asked Questions

My fireplace won’t stop beeping.

On an electronic ignition system, there are many safety measures set up to protect the unit from misbehaving. If your fireplace is beeping at you, you need to read your owner’s manual to see what the beeps could mean. Some will beep once, some will beep three times and some will do both, depending on what the problem is. If all else fails, change your batteries, it could be that your batteries are low and even if the unit is on regular electricity, the low battery will cause the module to beep.

Another reason it will beep is because of failed flame rectification. If the unit attempts to light and fails (the length and number of times will vary from manufacturer to manufacturer) the unit will go into “lock out” mode and will need to be reset before you can attempt to light it again. The most common reason for this is a Cold Weather Pilot and the easiest way to avoid this is to keep your unit in CPI once the temperature drops below 60°F.

Do I have to keep my fireplace in CPI? I don’t want to waste propane.

A constantly lit pilot light burns about 5 gallons of propane a month, hardly a dent in a large tank. If you don’t want problems lighting your stove in the winter, keep the pilot in CPI mode until it warms up.

My fireplace went out suddenly but then came back on, what’s wrong with it?

Chances are, nothing. Many new gas appliances have a shut down requirement, usually every 24 hours. If there is no flame adjustment or other action, the module shuts the system down and reboots it just to make sure everything is working properly.

Do electronic ignition systems require electricity?

Yes. Your new appliance will run on your house electricity for the most part. In the event of a power outage, it will run on a battery backup. All of the functions on the remote and the stove should work with the exception of the blower(s).