If you’ve been having a hard time trying to fill your 4WD, Caravan, RV, Motorhome or Camper Trailer water tanks, don’t feel bad. They are often very difficult to fill, and it can be incredibly frustrating too. No matter though; we’ve got the ultimate solution that makes filling your water tanks a breeze.
It’s also faster, spills less water and has a much greater chance of getting your tanks full every single time. Not sure where to fill water tanks up on the road? We’ve got you covered!
Why is it hard to fill your water tanks?
There’s a simple explanation for why its often so difficult to fill water tanks, and its the very thing you breath. As you fill your tanks, the water going in needs to push the air inside the tank out, or you end up with a pressure lock and it won’t be able to fill.
If the tank is full of air, and it cannot make its way out easily (like many cannot) you’ll find it almost impossible to get water in, which results in air locks, bubbling and burping and a frustrating time trying to fill your water tanks up.
The water tank breathers in essence then, are the reason for your difficult time to fill the water tanks, but there’s a way to fill your tanks without worrying about the breathers at all!
Now, if you have no issues filling your water tanks (and some people get lucky), then you might not find this useful. However, it is an alternative that has greatly improved the way a lot of people fill their tanks!
How to easily fill your water tanks
The easiest way to fill your water tanks then, is to allow the air to escape as easily as possible. This means opening your breathers up if possible (most are permanently open anyway), and leaving the main (or traditional) fill point open to atmosphere.
Generally this just means unscrewing the fill point cap, but some have ball valves (like ours) behind the cap too.
Fill from the bottom (drain point)
From there, find out where the drain point is for your tank (s), and hook a hose connection up. Yes, you read that correctly; fill your water tanks up from where you drain them out. Ignore the traditional fill point; the new fill point is your traditional drain!
We’ve installed two connection points on the bottom of our Hybrid camper trailer that a hose can be plugged into (where you’d normally drain the tanks), and they both fill our tanks.
As water comes in from the bottom, air that is sitting on top comes out the breather and normal (traditional) fill point without any resistance at all. The drains (where we fill up now) simply have a male connection point and a ball valve.
With this technique, you can fill at the fastest rate too, as the air will easily work its way out from above the water level, and out the breather and/or traditional ‘fill point’. There’s no trying to send water in, and air out through the same hole, or relying on woefully undersize breathers to let the air out.
When you fill your tanks up, its generally at a rate that is substantially faster than what you would ever consume in the caravan or camper trailer, and the breathers are often just not suited to relieve the air fast enough, which causes it to burp and carry on.
Now, I will mention that its important to ensure your tanks don’t get over pressurised when you do this. You should be able to feel, and hear air coming out of the breather and traditional inlet as you are filling, and if you turn the hose off, this should subside within a few seconds.
If it keeps going for some time, there’s a chance your tanks are not breathing properly and are being over pressurised.
Using a custom elbow
If for some reason you don’t want to fill from the drain point, the next best option is to make up a little elbow fitting that you can stick inside the fill point. This pushes the water in at a level where it can’t ‘bounce’ out, and the air will come out better.
These are literally a 13mm reticulation elbow to BSP thread fitting, which connects to a normal hose connection. Get a short length (around 20 – 30cm) of 13mm reticulation tubing and push it onto the other end of the elbow, and you have it sorted for only a couple of dollars.
However, the fastest way is from the drain, and you just wait until water comes out of the main fill point and you are done. Give the vehicle or trailer a bit of a shake to make sure all of the air is gone, and life is good!
What’s the benefits of filling from the drain?
It’s the fastest way, as you can crank the water pressure right up (until its mostly full). This means you reduce the fill time to as little as possible, and anyone waiting behind you gets the best possible deal.
There’s nothing worse than being stuck in a queue of 5 people waiting for water, and seeing someone trickle water into their tanks as it keeps bubbling back out at them.
You virtually eliminate the risk of over pressurising
I’ve seen tanks crack because people put water in at a rate that is faster than the air can escape. This depends on how your setup is done, but when you fill from the drain your air can escape via the normal fill point plus the breather, and there’s almost no chance of any over pressurising.
You spill far less water
Time and time again I see people standing next to their fill point, getting drenched each time the tank burps, and spits water back at them. By filling from the drain point, you can fill at full bore, then taper the flow off when it starts to bubble and spit, and turn it off when its nice and full.
Water is a precious commodity, especially in many parts of Australia where rainfall has been poor for many years.
Also, you have to pay for water in more and more places today too. The more you spill, the more it costs you!
You don’t have to stand there and hold the hose
When we fill our hybrid, I literally plug the hose on, open the valves and I walk away and do something else until I hear it start to burp and carry on. You don’t have to stand there with an elbow, adjusting and making sure its going in, or doing the right thing.
When its full, its full
How many times have you thought your water tank was full because it was bubbling and spitting out at you? When you fill from the bottom, as soon as water starts coming out the top its completely full, and there is no possible way for air locks to still be present.
Cap the drain off when you are done
If you are going to use your drain point, I recommend you have caps that you put on to seal it up. Wasps (and other bugs) will go inside and block it up, and at the very least you’ll end up with muck in your tank that you don’t really want.
We had wasps build a nest in our water tank drain point, and they blocked themselves in and died!
Get a hose with a valve on the end
Another hugely helpful tip that we have found is to get a plastic fitting with a valve on the end, so you can control the flow of water. When you travel Australia you’ll find that some water sources are super slow, and others are almost enough to high pressure clean your car.
By being able to simply twist a fitting to make the water slow down you save water, eliminate the need to kink the hose and make life so much easier.
Consider getting a flow meter
You can get battery powered flow meters that connect onto your hose, which are useful in knowing how much water you’ve actually put in.
If you know your tanks are 200L in combination and they are half full when you pull up, you know that if you’ve put near on 90 – 110 litres in you are probably exactly where you need to be.
Fill your tanks with ease
This is a super common question that I see online, and hopefully it makes life significantly easier for a big chunk of people. If you are struggling to fill your caravan or RV water tank, just do it from the drain instead!
We came across this out of necessity, with 270L of water in our Reconn R2, and 50L in our Isuzu Dmax.
Have you had a hard time filling your water tanks? Give the filling from the drain option a go, and you might be surprised!
Brilliant idea hadn’t thought about doing ti that way,i couldn’t get water into our second tank at all ,only filled up the first tank and then it would just overflow thnkyou
Yep, its super simple, and seems to sort out a heap of issues people have. Just watch the air can escape easily and you don’t end up with water going where you don’t want it the first time!
All the best