This one shows the results of a bypassed rollout switch. This video is part of the heating and cooling series of training videos made to accompany my website. The flame roll out switches are around the burner box and have a tiny red reset. If you bypass the roll out limit by hooking it's two. We have a picture of some limits and rollout switches below. We have a picture of me testing a rollout below. You can test a rollout or limit by setting your volt meter to “Volts AC” then with the furnace turned ON your should get 24 to 28 volts AC between each terminal of the limit or rollout to a good ground. If you have any questions about furnace flame rollout, or if you’d like a heating system serviced or installed in your home, contact Jerry Kelly, your St. Louis furnace installation and repair contractor. We provide service all over the St. Louis area, including towns like Maryland Heights, O’Fallon and St. It is not recommended that you bypass a flame rollout switch, for several reasons. Flame rollout switches trip when the heat exchanger is damaged, or the vent is clogged. If there is a fluctuation in gas pressure within the furnace, it can also cause the flame rollout.

Can You Bypass A Flame Rollout Switch Relay

When your furnace is well-maintained and working properly, it doesn’t
pose any safety risks to your home. However, if your furnace is poorly
maintained, experiencing operational problems or reaching the end of its
operating life, it can encounter some safety issues that can be of serious
concern. One such safety hazard is a flame rollout. Today we’re
going to talk about what a furnace flame rollout is, the dangers it causes
and what you can do to protect your system from a flame rollout!

What is a furnace flame rollout?

When your furnace is turned on, its burners emit steady flames that are
supposed to be confined inside of your system’s combustion chamber.
Under certain conditions, inflammable combustion gases can build up inside
of the combustion chamber and starve the flames of oxygen. When this happens,
the flames grow larger and larger in an attempt to receive oxygen, eventually
causing the flames to “rollout” of the confines of the combustion chamber.

Flame Rollout Switch Open

You can detect a furnace flame rollout if you notice any signs of singing
or discoloration on the exterior of your furnace’s combustion chamber
or other nearby parts. You might also be able to see the rollout occurring
if you inspect your system at the right moment.

What causes a furnace flame rollout?

As we mentioned above, flame rollouts occur when inflammable combustion
gases build up inside of the combustion chamber. This can happen for several reasons:

• Soot buildup prevents combustion gases from exiting the combustion chamber.
• The flue pipe is blocked somewhere, preventing combustion gases from being
  vented outside.
• The heat exchanger is cracked.

Furnace Flame Rollout Switch

Why are furnace flame rollouts so dangerous?

When flames are rolling out of your furnace’s combustion chamber,
they will heat up the temperature around parts of your furnace that are
not designed to handle such high temperatures. This will not only damage
some of your furnace’s components, but also possibly cause something
nearby to catch fire.

In addition, a furnace flame rollout might be an indication that your heat
exchanger is cracked, which would suggest that carbon monoxide is getting
into your home’s air.

How can you protect your furnace from a flame rollout?

Flame Rollout Switch Troubleshooting

Your furnace actually has a safety device that is designed to detect flame
rollouts. It’s called a flame rollout switch, and it cuts off the
gas supply to your furnace when it detects higher temperatures than normal
immediately outside the combustion chamber. The best way to ensure that
this device is working properly, and to prevent flame rollout in the first
place, is to schedule a tune-up every year so that we can look for signs
of rollout and take care of issues before your system becomes a safety hazard.

Manual Reset Flame Rollout Switch

If you have any questions about furnace flame rollout, or if you’d like a heating system serviced or installed in your home, contact Jerry Kelly, your St. Louis furnace installation and repair contractor. We provide service all over the St. Louis area, including towns like Maryland Heights, O’Fallon and St. Charles, MO.

How to Keep the Furnace Clean in Your St. Louis Area Home » « What are the Effects of Low Indoor Humidity on the Health of You and Your Family?