RV Furnace Clicking but Not Lighting

There are plenty of reasons why your RV furnace not lighting. First of all, it could be a faulty sail switch. If it’s a faulty switch then just simply replace it.

The other thing is that if you have pets, dust and fur, and junk can get in there and interfere with that switch being unable to turn on.

In this post, you will find a nice step-by-step guide for you about causes and solutions of RV furnace clicking but not lighting.

RV Furnace Clicking but Not Lighting

Role Of A Furnace In An RV

The role of a furnace in an RV is basically keeping the RV warm. Especially in winter camping or full-time RVing. It will keep you warm and cozy while you’re sleeping or adventuring.

Furnaces warm the RV quickly and efficiently no matter how cold it is outside. Since they run on propane there are no electric hookups needed. And the most useful thing is they are already included with the RV so there is nothing extra to buy or install.

If you have a basement the furnace can route heat down there to prevent plumbing from freezing. They vent externally so they won’t contribute to moisture and condensation build-up inside the rig. If you’ve two furnaces then two zones give you the flexibility to heat just the front or the rear of the RV.

Possible Reasons and Fixes of RV Furnace Clicking but Not Lighting

There could be many reasons behind the furnace not lighting even though you might hear the clicking sound. The most likely reasons and their fixes are:

1. Blower Wheel Stopped

Is the blower fan running? This is the very first thing you need to check. If your furnace is not blowing air that means it’s not getting 12Volts power.

If it’s not, stop right there. It could be a reason that your furnace not lighting. So, check that the fuse is properly inserted and hasn’t blown.


Make sure you have sufficient battery power. Your battery power should be reading at least 12 volts and preferably higher. You can check this using your battery meter or get a more accurate reading using an ammeter.

Try the furnace again with a fully charged battery or hooked up to shore power. If your blower motor is now running, you’re good to go.

2. Sail Switch Gummed Up

Another reason could be the gummed-up sail switch. This is a switch that senses airflow and decides whether it’s going to actually tell the furnace to ignite or not. These switches can apparently get gummed up with dust, pet hair, and all sorts of stuff.


The solution in this case is simple. You will have to take it out. Then, give it a thorough cleaning and reinstate it.

It is better to practice cleaning the sail switch at regular intervals. This way, you can be sure it is probably not the sail switch causing the problem.

3. Lack of Gas Pressure

Lower gas pressure hinders heat generation. Heat generation increases as the pressure increase. So, if the pressure gets low then your furnace with have trouble generating enough heat.

Now, turn on all the burners on your stove. Do they have a strong blue flame? If the flame is weak or yellow it could mean your gas pressure is too low.


Try turning all the burners with a completely full propane tank. If you still have signs of low gas pressure it might be a faulty regulator which is thankfully fairly inexpensive and easy to replace yourself.

4. Flame Sensor or Electrode is Full of Dirt

If your gas pressure looks good and your furnace is still not lighting then things get more complicated and it’s time to check the flame sensor and the electrode.


This might be the time to call a qualified technician or if you are comfortable working with LP gas systems you can take out and inspect your electrode and burner.

Your electrode needs to be cleaned, and free from corrosion. Your burner also needs to be cleaned and intact to produce a sufficient flame.

5. Water Intrusion

If your furnace is lighting but going out after a few seconds then maybe you want to check your control board. Water intrusion on these types of furnaces is actually a big and known issue. Water would mess up all the electrical connections and cause a short circuit.


Take out the circuit board and inspect if there’s any water underneath the board. If your circuit board is drenched in water, replacing the board can solve the problem.

If you’re comfortable doing your own repairs it may be worth replacing the board. And if that doesn’t work or you’re simpler, or not comfortable DIYing it, then it might be time to call up your friendly local RV repair technician.

Frequently Asked Questions (FAQs)

Why Is My RV furnace clicking but not turning on?

However, if it continues to click without lighting, you should have a qualified HVAC technician look at it. The problem can be a faulty or clogged ignitor or loose wiring.

Can Hear Your RV furnace click on but it does not fire up?

Most likely, your furnace’s spark igniter is attempting to light your pilot light or burners but failing to do so, which is why it is making a clicking noise and not producing heat.

What is a reset button on an RV furnace?

Reset buttons are included on every furnace. They are found inside the blower compartment and are often red or yellow.

Why won’t my RV furnace heat up?

A sail switch problem may frequently cause an RV furnace fan to operate but not generate any heat. A potential issue is a low battery voltage.


These tips should help you with your RV furnace troubleshooting. Make sure you keep the sail switch area cleaned out, and free from fur and dust. It’s good every year to just check the furnace carefully, and follow the ducts as far as you can.

Sometimes it’s not easy to get to it but follow the ducts and make sure there are no holes in them, there’s no rat living in them and if you follow all the instructions, you should actually be able to keep your furnace running long and healthy. Happy RVing.