If you’ve recently purchased a school bus and removed the seats to convert it into a tiny home on wheels, you’re probably wondering, what the heck are these am I going to do with these rear bus heaters? It’s enough that I have to build around wheel wells, now I have to build around these bus heaters too?! Today we are going to talk about what those bus heaters are doing back there, whether it’s safe to remove them from your skoolie conversion and guide you through the process of how to remove your school bus heaters.
What Does the Rear Heater Do?
Before getting all gung-ho and ripping out wires and hoses, it’s very important to go over what these heaters are actually doing back there because it’s more than just heating the students in the back of the bus! These heaters work very similarly to any other heaters that you’d find in a car, truck, or bus (I can’t speak to what modern combustion or electric cars are doing nowadays). They don’t just generate heat out of nowhere and they usually aren’t using much or any electricity to generate that heat either. These heaters actually work quite efficiently because they pull heat directly from the engine by running coolant through them.
Along with expelling heat to keep students warm, these heaters are also helping to cool the coolant and engine to keep them running at ideal temperatures! These bus heaters are really just radiators that run hot coolant from the engine through them and use fans to blow the heat off of them.
It is very important to keep in mind that they play a part in keeping the engine cool because when your skoolie is fully built out, it is going to be HEAVY, and your bus may get HOT when trying to climb steep mountain roads tugging multiple tons of house behind it! Running your heaters can help pump some of that heat out of the engine and through the heater, but that’s only if you still have it. You will lose this option if you remove the heater.
Should I Remove the Rear Bus Heaters from my Skoolie?
With all of that said, should you remove your school bus heaters? Like many other things, It all depends on what you’re wanting to do with your bus, whether you need the extra build space, and if your bus can handle having that cooling component removed from its system and still maintain ideal operating temperatures. Let’s start with the first thing you need to consider.
What do you want to do with your bus?
This question plays a huge role in whether or not you should remove those rear bus heaters. If you are planning on building out your skoolie and parking it on your land to function as an Airbnb, then heck yeah remove those heaters! Even if you have to move the bus, it’s probably not going to be a long road trip up steep mountain roads right? Furthermore, being that your skoolie is functioning entirely as a living space and not at all as a transportation vehicle, you need to prioritize build space and function over just about everything else.
This changes drastically if the idea for your bus includes being a full-time skoolie with intentions of traveling deep into the mountains all the time. You also need to consider the length of your bus and how heavy your build will be. Keeping the engine cool becomes increasingly more important the longer your bus gets and the heavier your home is going to be.
If you have a 40-foot bus and are intending to fill the capacity to its entirety, and you plan to keep a motorcycle on the back, have a large roof deck on top, and tow a jeep behind it, you may want to consider keeping your rear bus heaters as your engine is going to be working really hard all the time and may need some additional help in keeping operating temperatures in check. Another thing you can consider is making some modifications to the cooling system in the engine bay in order to maximize the cooling potential.
What if I want it all but still want to remove the rear bus heaters?
That’s a great question! I’m so glad you asked! There are still options for you if you are looking to remove the rear bus heaters but also have a long and heavy bus and are wanting to travel on some steeper mountain roads. Ellie and I are in this boat, granted we have a shorter 26-foot bus but we have removed our rear heater and still plan to make some trips on steeper roads in the future.
Your best option here will be to improve the cooling system of the bus inside the engine bay. There are a few different routes you can go with this but I’d only recommend this for those with some auto mechanic experience or those that are willing to seek the help of someone with mechanical experience. The process will also differ heavily here based on the year, make, and model of your bus and the type of engine inside.
You will need to consider how much extra room is available and how much additional cooling power you need. Upgrades can consist of any combination of replacing or upgrading your radiator, adding or upgrading your radiator fans, and adding an additional radiator with or without fans. I’m not going to go too deep into this as it is beyond to scope of today’s article but you should know that there are options available.
Don’t Like to read? Check out or video guide on How to Remove Bus Heaters!
How to Remove School Bus Heaters
Step 1: Gather Tools
There are only a few tools that you are going to need for this job and chances are that you’ve got most of them handy already which is convenient! Those that you don’t you can easily pick up at your local auto parts or hardware store, or we have links to them below! They are as follows:
Step 2: Shut Off Coolant Flow from the Engine
Bus manufacturers make it pretty easy on us here which is GREAT! This is another step that may be slightly different based on the year make and model of your bus but should remain fairly similar. Heading to the engine bay, you should find two coolant shutoff valves on the coolant lines running from the engine, back into the cabin of the bus. I suppose it’s possible that there is only one shutoff for both outflow and inflow of coolant but I’d guess it’s more likely for there to be two coolant shutoff valves like our bus had.
Ours functioned similarly to how a water spigot does in that we had two little wheels or knobs that we had to close. They were all the way to the left while open so we closed them by turning them all the way to the right. Your valves may just require a quarter or half turn in one direction or the other if they are a different style of valve. Once you block the coolant flow from the engine, it is important to note that there will still be a significant amount of coolant in the heater that you are removing, and the lines that run to and from the heater. These shutoffs just ensure that we won’t be draining additional coolant from the engine.
Step 3: Disconnect Electrical Connections
Usually dealing with wiring can be a little bit daunting but the task is quite simple here as we are only dealing with a few wires. With that being said, I would highly encourage you to take a photo of the wires before you remove them to ensure you know where they were when the heater was functioning. If you deal with any issues with the bus starting or other systems failing after removing the heater, you will know which wires go where in order to troubleshoot the problem.
If you can’t take a photo or the wires all look the same, mark the plastic connectors with a sharpie. For example, mark the first two wires that connect to each other as 1. Then mark the next two wires that connect with 2’s. So on and so forth.
We only had two wires running into the heater from our fuse panel. Once they go to the heater they broke off into four total wires. All in all, very easy in this department. When you are unplugging wires, they may be old and brittle depending on the age of your bus, so do your best to be gentle with them and not break any.
Step 4: Remove Coolant Lines from Bus Heaters
Here is where things start to get interesting. The job doesn’t get any more complex from here but dealing with old rubber hoses can be incredibly infuriating! There is one hose that runs coolant from the engine into the heater and one hose that runs coolant out of the heater back into the engine. You don’t necessarily need to know which is which as both hoses will be removed. I’d highly recommend the keep the heater flipped on its side with the hose side up toward the sky. This will ensure that once the hoses are removed there will be minimal coolant spillage as the heater is still full of coolant!
Our bus is 25 years old so these hoses have pretty much welded themselves onto the fittings. The only way I could get them off was by using a flathead screwdriver and prying them off of the fittings. One thing to note, even if your hoses aren’t too old, chances are the fittings are barbed to stop the hoses from slipping off so you will still need to pry the hoses over the barbed section of the fittings.
You will need to start by removing the hose clamps. These will require either a wrench or a flathead screwdriver to loosen up. Once they are removed, you can begin prying at or cutting away the hoses. It may be easiest for you just to chop the hose before the fitting if you have no intentions of reusing or selling the heater. Be ready with your bucket to catch the coolant that inevitably spills out!
Step 5: Drain Coolant from Bus Heaters
Don’t skip this step as it could create a mess for you later on. Once you’ve removed the hoses from the heater, go ahead and drain as much coolant from the hoses as you are able to. Then from there, you can drain all of the coolant from the heater itself. There are a few options for disposing of or reusing the coolant once you’ve drained it.
If your bucket was clean and you were able to collect the coolant without dirt or debris, feel free to throw it right back in the coolant reservoir on the engine if it needs topping off. Otherwise, throw it in a milk jug or old coolant jug if you’ve got on laying around and take it to your local auto parts store to recycle it free of charge!
Step 6: Remove the Coolant Hoses Entirely and Clean the Fittings
The next step in the process is to destroy the evidence! We will need to remove the coolant lines from where they begin to run back through the driver heater and into the engine. If you check out our video you will see that we left a few feet of hose protruding out from the driver heater area. We will clean that up later and cut the hose back so it doesn’t run out of that driver console area at all. It is up to you how exactly you want to do that.
Removing the coolant lines here will be the same process as before. Use a wrench or screwdriver to loosen the clamps then pry the lines off of the fittings. Remember there will probably still be some coolant in the lines or coming from the driver heater so be ready to catch that.
Now, we need to make sure that the fittings are as clean and smooth as possible so when we install the new hose to close the loop, there is a good solid connection and we don’t have any leaks! To do this, we used a few wire brushes and some brake clean. You can also use a razor blade or sandpaper to scrape off any old hose or adhesive that remains on the fittings. Once the fittings are all nice and smooth, you are ready to close the loop!
Step 7: Close the Loop!
This is the final step of the process! Here we are going to make sure that once we reopen the coolant lines we don’t get coolant spraying everywhere and fry our engine! The specific hose that we needed was a one-inch radiator hose. Make sure that whatever hose you get can sustain temperatures above 200 degrees Fahrenheit as the coolant can get really hot! It is easiest to just get radiator hoses to be safe. Your ideal hose is probably going to be a U-shaped hose but we were only able to get a weird zigzag shape at our local hardware. We were able to bend the hose enough without kinking it and restricting coolant flow too much which is important.
Before you slip the new hose onto the fittings, make sure you get two hose clamps around the hose first. These can be new clamps but there is no problem with reusing old clamps if they are still in good condition! These tend to be fairly sturdy over time. Once the clamps are on the hose loosely, slip the hose over the fittings. You may need to force it on there using some strength but that’s good and shows that the hose won’t fall off easily. Try to get at least an inch or so of the hose past the barb if possible so that you can tighten down the hose clamps past the barb.
Step 8: Clean Up
And there you have it! That’s pretty much all there is to it! Before you consider it a job well done, make sure you reopen those coolant valves that we closed off earlier! Your front and driver heaters will not work unless these valves are open! Along with that, try to clean up as much spilled coolant as possible. It’s fine if you can’t get it all but it’s generally not a great idea to have liquid with random chemicals soaking on your metal floors.
It’s also probably a good idea to give the bus a quick test drive to make sure you aren’t leaking at all! Turn any front heaters that you have on full blast to make sure you get coolant running through them and try to get the bus up to operating temperature to ensure the coolant is flowing through the whole system. If everything stays dry you should be good to go!
Conclusion
As I mentioned before, this job isn’t nearly as hard as it might look but could be incredibly valuable in saving some space in your skoolie build! If you get stuck at any part in the build, each step links directly to our video showing exactly what to do! If you have any questions or are wondering if this is something you should take on, feel free to comment below or reach out to us on our socials! Until next time, thanks all for reading, and happy travels!
