Suburban RV Furnace Won't Light at Extreme Temperatures

Cold weather is notorious for causing havoc on RVs and their equipment. When it comes to your furnace, rather than lighting, it’s possible that the gas line had moisture in it that froze. Ice buildup might prevent gas from reaching your furnace.

In most cases, RV furnaces quit operating due to inadequate battery energy or unclean air filters. Check the air filters and make sure you have shore power or a generator. If you’re boondocking, make sure the batteries are charged and the inverter is turned on.

Let’s look at glance why your suburban RV furnace won’t light at extreme temperatures:

  • Low battery
  • Blown fuse
  • Gas pressure
  • Clogged filter
  • Faulty compressor
  • Problem with thermostat
Suburban RV Furnace Won't Light at Extreme Temperatures

6 Reasons Suburban RV Furnace Won’t Light at Extreme Temperatures

Read these detailed problems and have good idea about how to deal with.

1. Low Battery

Low voltage from the battery bank is the most common cause of your RV’s furnace not turning on. The fan within the furnace requires 12-volt DC electricity to operate.

This current is supplied by your RV’s battery bank. Most RV manufacturers install only one battery in their vehicles since it is all that is required to power the 12-volt DC circuit.


When the cutoff switch will continue to turn off battery power to serve as a reminder that your batteries are running low. Adding extra batteries is the solution.

Most RVs come standard with a single 100-amp hour battery. If you wish to operate the furnace for 8 hours, you need to have at least 200-amp hours.

2. Blown Fuse

Fuses are used in RV furnaces to prevent the circuits within from overloaded. Many technical problems with an RV’s furnace may be traced back to a blown fuse, which is generally caused by broken wiring or a short circuit.


If a fuse blows, you must replace it. If a fuse blows, the machine will not work since the part is meant to break the circuit. If you’re familiar with electricity and automobiles, you should be able to perform some RV maintenance on your own.

Take all required measures and avoid taking any needless risks. If you are unfamiliar with electricity or cars, you should see a specialist.

3. Gas Pressure

All gas appliances are programmed to function at a normal supply pressure of about 3 PSI.

Because the pressure within a propane tank is substantially higher, a propane regulator is utilized to regulate the gas pressure.

If there is a residue in the propane tank, it might cause the regulator to malfunction or work intermittently.


An empty tank will not create any pressure, so be sure your levels are correct.

If you suspect a problem with the gas supply, the most probable component to fail is the gas regulator.

Fortunately, they are affordable and readily replaceable.

4. Clogged Filter

When the temperatures drop, your heating system’s insufficient airflow will undoubtedly struggle to keep you warm.

Your furnace may be providing enough heat, but if there is an issue, such as a broken blower fan, a clogged air filter, or damaged ductwork, hot air will not be distributed throughout your RV.


Start with the simplest solution: inspect your furnace’s air filter and replace it if there are signs of dirt and debris trapped inside, keep in mind that cleaning the filter will also work. 

If this does not cure the problem, you will need to contact a skilled professional.

5. Faulty Compressor

Cleaning your system is a vital aspect of keeping it working well, but it may not resolve this specific problem. Compressor-based systems that use Freon to cool might develop gradual leaks or run out of Freon over time.


They can be recharged, but considering the risks of Freon, we recommend having an expert handle it. They can also make sure there is no leak in the compressor.

6. Problem with Thermostat

If your furnace is running continuously and your RV still isn’t warm, it’s possible that your thermostat isn’t operating properly.

Set your thermostat 5 degrees higher than usual and check to see if warm air is being blasted through the vents to see if this is the problem.

If this does not occur, there is an issue with your thermostat.


Installing an RV thermostat may be as easy as removing and changing a few screws.

Or, it might need a whole rewiring operation. It all depends on the type of thermostat in your RV and the type of thermostat you want to replace it with.

Important: Why Should You Avoid Straining the Furnace In Cold Weather

The internal temperature is likely to dip so low in extreme cold that your furnace will struggle to warm the RV. Instead, set your programmable thermostat to hold at roughly 70 degrees Fahrenheit or select an energy-saving temperature that is only two or three degrees lower than room temperature.

Resist the urge to turn the thermostat all the way up. Your furnace may be incapable of sustaining your desired temperature during periods of extreme cold, especially if it is older or small.

A high setting can cause your furnace to run too frequently, perhaps damaging the components. Use your typical winter temperature setting or one that is two to four degrees higher for the best furnace performance. You could get a bit cold, but you’ll elongate the expected life of the furnace.

In extreme cold, your furnace is working overtime, so it collects more dust and debris than usual. Debris buildup impedes airflow, impairing your furnace’s performance and causing unnecessary wear on the components.

To prevent these issues, inspect your furnace’s air filter at least once a month and replace it if the filter material is completely covered in dust.

Frequently Asked Questions (FAQs)

Why Is My RV furnace not kicking on?

Low battery voltage might be the cause of your furnace not turning on at all.

Why does my furnace not turn on when it’s cold?

Filters that are clogged reduce airflow and might prevent the furnace from starting. Other reasons it won’t start include incorrect thermostat settings, failing to turn on the gas line, or defective pilot light.

Why won’t my RV furnace heat up?

Low battery voltage is one of the potential issues. So, make sure your RV’s house batteries are in good working order.

How do you reset an RV furnace?

The lockout problem can be cleared by turning off the thermostat and lowering the temperature to a level that does not cause the furnace to switch on.

At what temperature does an RV heat pump stop working?

As the temperature drops below 40 degrees Fahrenheit, the refrigerant in RV AC/heat pump systems absorbs less and less heat from the outdoors.


Furnace parts can break at any time of year, and it’s possible that your furnace and its interior components are just too old.

Consider purchasing a new furnace or updating outdated parts to ensure that your furnace does not fail you when it is chilly.

If your furnace is spewing chilly air, cleaning the filter may be all that is required, but you should also check your propane and battery power.

In cold temperatures, Suburban and other brand furnaces may fail to ignite. The idea is to locate and replace the problematic component as fast as possible.