While it is important to keep all your appliances in good condition, the furnace is the one appliance that is truly out-of-sight-out-of-mind and is of utmost importance in colder weather. This article serves as a reminder about furnace maintenance.
An RV furnace requires almost no maintenance. If necessary, clean or vacuum out the ducts if they get dusty or dirty. Regularly inspect the furnace intake on the outside of the RV for debris, insects, or other restrictions. Restrictions in the air intake can cause incomplete combustion. The by-products of incomplete combustion are Carbon Monoxide (CO) and soot. CO is an odorless, colorless, toxic gas. Incomplete combustion can be indicated by the presence of soot on the furnace exhaust on the outside of the RV. However, this is not a given and is another reason to have your system annually inspected.
Since RV furnaces do not have intake filtration like the ones in our homes do, it is common for the system to get dust and lint caught in it so the furnace either does not work properly or doesn’t work at all. Depending on the make and model of your furnace, you will either have an access panel on the outside or inside of your coach. The latter will likely be behind a panel that says “not for storage” or something similar. Check that space and vacuum it as necessary. Remove the cover from the furnace housing and vacuum the inside of the appliance.
A common failure mode for an RV furnace is that the blower runs for a short time, then the furnace shuts off. This is a result of the burner not lighting and can be caused by several things. In many cases, it is the result of debris in the sail switch (also called the “air prover”). This is a relatively easy component to clean. Refer to your owner’s manual to learn how.
The order of operation for an RV furnace is as follows:
- The thermostat calls for heat
- The furnace blower starts after a short delay
- The blower runs for several seconds in order to purge any non-combusted propane
- The control will check airflow via the sail switch
- If it is closed, the burner will attempt to ignite
Many owners aren’t aware of this order of operations, so I am including it here. If you are having problems with your furnace, this list may help you understand what function is failing so you can better communicate to your service provider.
While the RV furnace is a reliable, largely maintenance-free appliance, keeping it clean can help to ward off furnace problems when you may need it the most.
I must briefly include this as a reminder that it is extremely important to have your RV propane system professionally inspected annually. Your local RV service center will make sure your system has no propane leaks, your regulator is working properly and outputting the correct propane pressure, and your appliances are all functioning as they should.
Failure to have your system regularly inspected runs the risk of your unit getting a propane leak, or your appliances not functioning properly, possibly resulting in incomplete combustion. Both of these conditions are potentially very hazardous. So, it is important to keep your unit properly maintained. The same applies to other regular tasks, such as seal inspections.
About the author: Steve Froese
Steve Froese, an avid RV owner, traveler, and Coach-Net member since 2013, is the principal of “A Word to the Wise Technical Communications”, a published RV author, certified RV technician, and licensed Professional Engineer. He frequently collaborates with the “RV Doctor”, Gary Bunzer, and has worked with the RVIA/RVDA as a technical and training writer and consultant. Professionally, he works as a quality engineer and musician. Watch for more of Steve’s work in upcoming Coach-Net publications.
Stephen S. ~ “I have used Coach-Net for several years. A true bargain for the services provided. Highly recommend!”