One of the best perks to tenting in an RV as an alternative of a tent is dependable cooling and heating. It’s rather more snug to get up and prep your espresso in a heated leisure car than climbing out of a moist tent to gentle your camp range and attempt to get a fireplace going.
Just like residential items, RV heating methods require common upkeep. But how will you service or restore an RV furnace in the event you don’t know the way it works? To preserve an RV furnace, you’ll must know the way it works.
An RV furnace heats air after which circulates it by means of your RV utilizing a fan. Most RV furnaces function on DC energy even when your RV is plugged into shore energy, permitting them to work at a campground or when tenting off-grid.
But there’s rather more to it. So let’s dive into every part it’s essential find out about working, servicing, and troubleshooting RV furnaces.
How Do RV Heating Systems Work?
There are two foremost varieties of RV heating methods: pressured air furnaces and hydronic heating methods.
In pressured air furnaces, outdoors air for combustion is force-fed by means of a sealed combustion chamber meeting and discharged to the outside, whereas inside air of the RV is moved throughout a warmth exchanger. This design ensures that no merchandise of combustion are blended with the inside air.
Hydronic heating methods use a heated floor to warmth water that’s distributed to radiators all through the RV. That floor could be heated by burning gasoline (i.e., propane or diesel), an electrical aspect, or utilizing major engine coolant to warmth that floor. Some hydronic heating methods warmth potable water and can be utilized for engine preheating.
Technician Tip: All RV heating methods ought to have a knowledge plate containing the producer, make, mannequin, serial quantity, and enter and output (measured in BTUs/hour) of the equipment. This plate helps you establish your equipment for particular service and upkeep procedures. Your proprietor’s handbook can even enable you to perceive the kind of heating system you’re working with.
How Does an RV Furnace Work?
If you’re working with a pressured air RV furnace, warmth is distributed all through your RV utilizing a blower fan that’s powered by a small motor. Most pressured air furnaces burn propane to warmth air, however some make the most of diesel gasoline (extra frequent with hydronic heating methods).
Before we define the method, let’s outline just a few key phrases.
A sail swap is the primary security swap in an RV furnace. It prevents your furnace from making an attempt the ignition sequence if the blower motor isn’t working at a minimal of 75% of its rated velocity.
A restrict swap is the second security swap. It opens at a preset temperature to forestall overheating. The restrict swap is mounted on the warmth exchanger or the burner meeting housing. It shuts off the burner however permits the combustion blower to proceed working to decrease the gear temperature.
Safety Tip: The restrict swap does NOT act as a thermostat. If your blower by no means shuts off, however your burner is biking on and off at common intervals, your RV needs to be inspected by a certified RV technician instantly. This is a symptom of an overheating restrict swap, which may outcome from blockages, defective elements, or LP gasoline adjustment points that create a really harmful state of affairs.
When you flip in your RV furnace, right here’s a basic overview of what occurs if it’s working correctly:
- The thermostat is turned on and indicators for warmth.
- An electrical present is shipped from the thermostat to the time delay relay constructed into the circuit board, which closes to energise the blower motor after a delay of 10-20 seconds. If the motor isn’t reaching 75% of its rated velocity, potential points embrace low DC energy, a defective motor, a blocked return air inlet, or a blocked exhaust.
- When the motor comes on top of things, the sail swap is moved by the airflow to shut a micro-switch and proceed the circuit. The micro-switch is about to require a minimal fan velocity to shut. If the motor isn’t working quick sufficient, you’ve a sticky swap, or there’s an airflow blockage that doesn’t enable the swap to shut – the present can be interrupted. This circuit is impartial of the thermostat and motor circuit.
- The sail swap closes, sending energy to the restrict swap, which then sends energy to the circuit board. Under regular operation, the restrict swap is closed and opens at a preset temperature to forestall overheating.
- The circuit board delays ignition for 10-20 seconds, permitting the blower motor to purge any gasoline remaining within the combustion chamber.
- The circuit board opens the gasoline valve and sends a high-voltage present to the electrode.
- If ignition happens, the electrode senses the flame and sends a present again to the management board, stopping the high-voltage spark and retaining the gasoline valve open
- If ignition doesn’t happen, the board will go into lockout mode and should be reset earlier than attempting once more. Most circuit boards will pause for 20 seconds, then strive for 7 seconds. They’ll repeat this thrice earlier than going into lockout.
Technician Tip: A lockout may end up from a defective circuit board, defective electrode, defective gasoline valve, or any mixture of those points. If locked out, conduct a short inspection (LP gasoline on, no airflow obstructions, correct voltage, and many others.) after which swap the thermostat off and again on. The circuit board ought to present three extra tries.
Download this RV furnace diagram for a visible instance of RV furnace design. The pictured furnace is the Dometic DFMD30 Mojave Propane Heater. Yours might differ relying on the make and mannequin. Consult your proprietor’s handbook for the schematics of your RV’s furnace.
How to Reset an RV Furnace
To reset most RV furnaces, you’ll merely flip off the facility swap, wait about 10 seconds, and switch it again on. If your mannequin doesn’t have an influence swap, flip off the principle breaker to the furnace, wait 10 seconds, and switch it again on.
If no breaker exists, take away and reinstall the fuse similar to your RV furnace. That’s why it’s necessary to have your RV’s circuit breaker panel correctly labeled.
Learn extra about troubleshooting RV circuit breakers.
Where is My RV Furnace Located?
Your furnace location will depend on the producer and the floorplan. For instance, the furnace in my Sunset Park Sunlite Classic is situated beneath the fridge and to the left of my circuit breaker panel.
Regardless of your floorplan, perceive that the furnace itself gained’t be seen. You will see a return air vent (or vents) inside your RV and the air consumption/exhaust vent on the RV’s exterior. Here’s an instance of what your return air and exhaust vents would possibly appear to be:
Technician Tip: It is an effective apply to find the exhaust vent on the RV’s exterior and confirm the exhaust is current and clear. We’ve seen too many campers lean a garden chair in opposition to the vent, which may current a fireplace hazard.
If you’re looking for an RV, it’s a good suggestion to search for a mannequin with an exterior entry panel to service the RV furnace. This panel isn’t included on all RVs, particularly entry-level journey trailers.
How to Turn on an RV Furnace
Most RV furnaces are managed by a wall-mounted thermostat. Depending in your make and mannequin, you’ll have a digital management panel or an analog thermostat.
Most analog thermostats have a small On/Off toggle swap on prime, and RVs with a digital management panel may have a show for turning your furnace on and off. In both case, the next step is to show the thermostat as much as a setting above the present ambient temperature inside your RV.
If your furnace is functioning correctly, it is best to hear the blower motor activate and really feel air blowing out of your inside vents. Within 10-20 seconds, it is best to hear the pilot gentle ignite and really feel sizzling air popping out of your vents shortly thereafter.
If you allow your furnace on, it ought to proceed to cycle on and off to maintain the within of your RV on the desired temperature.
How Much Propane Does My RV Furnace Use?
To function your RV furnace, you’ll want an ample propane provide. If you’re not already acquainted, take the time to study connecting and turning on propane in your RV.
The quantity of propane your furnace makes use of relies upon largely on its BTU score. BTU is brief for British Thermal Units, which is a unit of warmth measuring how a lot warmth it takes to boost the temperature of 1 pound of water by 1℉ at sea stage.
A furnace with a better BTU score burns propane extra rapidly than one with a decrease score. So your first step can be figuring out your furnace’s BTU score, measured in BTUs per hour.
Before we get caught up within the numbers beneath, do not forget that your RV furnace gained’t run constantly when you flip it on and modify the thermostat. It will cycle on and off to manage the temperature inside your coach. This is important to recollect when calculating how a lot propane your RV furnace makes use of.
Let’s present an instance:
RV and Furnace Specs (let’s use specs for the Keystone Cougar 30BHS)
- Propane Capacity: 60 kilos
- Furnace BTU Rating: 30,000 BTUs/hr
- Electric Fireplace BTU Rating: 5,500 BTUs/hr
RV Furnace Propane Consumption Calculator
To begin, we should do not forget that propane containers can solely be stuffed to 80% of their whole capability. So whereas the Cougar’s marketed propane capability is 60 kilos, its precise capability is 48 kilos (60 x 0.8 = 48).
We can calculate the full BTUs of 48 kilos of propane from there.
1 pound of propane = 21,548 BTUs
48 kilos of propane = 1,034,304 BTUs
If our whole propane provide accounts for 1,034,304 BTUs, we are able to divide that by our furnace’s BTU score to estimate what number of hours our furnace would run earlier than that offer is exhausted.
1,034,304 BTUs / 30,000 BTUs/hr = ~34.48 hours
If we run our furnace and electrical fire concurrently, you’ll be able to really cut back your charge of propane consumption since you’re additionally counting on electrical warmth:
30,000 BTUs – 5,500 BTUs = 24,500 BTUs
1,034,304 BTUs / 24,500 BTUs/hr = ~42.22 hours
You can insert the suitable figures out of your RV into the instance above to calculate how a lot propane your RV furnace makes use of. But do not forget that these calculations are primarily based on 100% run time operation.
Other variables, corresponding to chilly climate and your required temperature setting, influence your furnace’s potential working hours on a full LP provide. For occasion, you’ll be able to roughly double the variety of hours your furnace will function in the event you estimate a 50% obligation cycle (i.e., your furnace will run for half the time you’re tenting).
Here are some tips about conserving propane in your RV.
Technician Tip: Remember there are different propane home equipment in your RV. The calculations above symbolize solely the out there working hours on your RV furnace, however they can be utilized if you understand the BTU scores of your RV’s different home equipment, corresponding to your water heater, fridge, range, oven, and out of doors grill.
How to Clean an RV Furnace
Pet hair generally is a drawback for sure RV furnaces. For starters, cleansing and disinfecting your RV after each journey retains it in the most effective form potential, and it’ll assist your RV furnace run extra effectively.
Inside your RV, use an RV vacuum to maintain mud and dander to a minimal. You can take away the return air vent to hoover mud and pet hair round your furnace unit on some floorplans. Just flip the furnace off earlier than doing so.
Outside your RV, use a transportable air compressor to take away mud, particles, pet hair, and bug nests out of your furnace’s exhaust tube. This is an effective factor so as to add to your seasonal upkeep record when winterizing your RV within the fall and dewinterizing it to prep for spring tenting.
Technician Tip: Please be aware that pressured air furnaces (not hydronic heating methods) are designed to function with out filters. If you have been to amass and discover a strategy to set up a filter in your pressured air furnace, it will void any present warranties and create a doubtlessly harmful state of affairs.
Troubleshooting RV Furnaces
Troubleshooting your RV furnace could be complicated, however we have now just a few downloadable assets to assist. You can even schedule a service appointment at your native Camping World Service Center for knowledgeable furnace inspection.
Here’s a choice tree for troubleshooting RV furnaces.
And right here’s one other particularly for thermostat-related points.
Beyond that, you are able to do some primary troubleshooting with the correct instruments.
Measuring Line Voltage Using a Digital Multimeter
- Measure incoming voltage on the wire connections on the facet of the furnace. The nominal voltage needs to be 10.5 to 13.5 volts DC beneath an unloaded situation. If lower than 10.5 VDC, the blower motor gained’t spin quick sufficient to activate the sail swap.
- Turn the furnace on and confirm the ignition.
- Measure the voltage on the wire connections on the facet of the furnace. The nominal voltage needs to be 10.5 to 13.5 volts DC beneath a loaded situation.
If measurements discovered are outdoors the appropriate vary, you’ll have a difficulty along with your RV’s DC energy provide (i.e., your battery). Consult your service handbook for additional furnace diagnostic ideas.
Evaluating Proper Airflow
- Open all discharge registers and any closeable registers inside your RV and confirm air discharge by really feel (or utilizing an airspeed indicator).
- Ensure that airflow isn’t hindered by throw rugs or different flooring coverings. Hindering your furnace’s airflow may cause the restrict swap to open.
- Verify that the discharge is heat and test that no carbon monoxide is current utilizing a carbon monoxide take a look at.
- Check the opening dimension for the furnace’s return airflow, guaranteeing it matches your unit’s working handbook specs.
Other checks are required to confirm the right operation of your RV’s propane system – to not point out the added complexity of hydronic heating methods. If and while you’re feeling overwhelmed and caught, please don’t hesitate to contact your native Camping World Service Center.
Do you’ve every other questions on furnaces and RV heating methods? Ask away within the feedback beneath.
Tucker Ballister is our Technical Content Writer. He’s a lover of the open street and the proud proprietor of a 2021 Sunlite Classic journey trailer (his third RV up to now). Check out extra of his RV adventures, gear critiques, and out of doors recommendation at thebackpackguide.com.