When You Should Drain Motorhome (RV) Water Heater & How To

Like many others, if you wonder when you should drain your motorhome, RV, or caravan water heater and how to do it, this is the article for you!

You should drain your motorhome, RV, or caravan water heater when you are not going to use it within two weeks or if you are expecting temperatures below freezing. This is to avoid bacterial growth, stale water, and a frozen and potentially damaged water heater, which can be expensive to replace.

To keep the water system in good condition is very important since it ultimately means keeping your health in a good condition.

Speaking of keeping the water system clean and healthy, I recommend checking my other article about the subject if you are wondering if you can drink the water from the tap in your motorhome. Hint; I do it.

A good routine is to empty the water heater after every trip!

Should I drain my RV water heater after each use?

You should drain the motorhome, RV, or caravan water heater if you don’t intend to use it within two weeks. You do not need to empty it every time you use the warm water or turn off the heater. An excellent routine is to drain the water heater after every trip to avoid bacterial growth, stale water, and algae.

It would be best if you did this with your whole water system, the water pipes, the fresh water tank, and the grey and black water holding tanks to keep the water system clean and always ready for the next trip.

If you want to know how to empty the fresh water tank and clean out the grey water tank simultaneously, you can look through this other article I have written since this is as important as draining the warm water heater after each trip.

I would always recommend draining the water heater and the water system after each trip because even if you have another trip planned within two weeks and feel confident you will use it within the two-week timeframe, what if the plans change? And you end up not going on the motorhome trip.

In a scenario like that, I would forget to drain the water heater and system due to a change of plans. However, if it is done after each trip before you park the motorhome, RV, or caravan, you are set no matter if the plans change or not, and it is a quick fix to drain it, so get used to it and make it part of your after the trip routine.

How To Drain a Motorhome, RV, or Caravan Water Heater In 3 Easy Steps

Here is a step-by-step guide on correctly draining the water heater in your motorhome with support from my truma water heater manual, their website FAQ page, and my experience. I also made a short youtube video above for better visualization of the process.

1. turn off the water pump

Turn off the water pump so you can open the faucets in the next step without pumping more water into the heater. Some water pumps work in a way that they start as soon as you open a faucet and stop pumping when you turn off the tap. In this instance, the faucets act as power breakers for the water pump. In this case, you will still have a power breaker in the control panel of the motorhome where you turn off the power to the water pump.

Another common way your water pump works is that you only have an on/off button for the water pump by the control panel, and when that one is on, the water pump will automatically start pumping when the pressure in the water pipes drops.

So, for example, when you open a faucet, it will flow water for a while, and then when the pressure has dropped a bit, the water pump will automatically start. In this case, the water pump doesn’t notice the difference between a water leak and an open faucet.

Ops, I got a bit sidetracked there. But, still, I think it is essential to know the difference and how your water pump works since if you have a pump that automatically starts when the pressure drops and it starts when you don’t use any faucets, then you probably have a water leak somewhere.

If the water pump starts when you don’t have any faucets open then you probably have a water leak somewhere.

2. Open hot water faucets in the kitchen and bathroom

Now it is time to open the hot water taps in both the kitchen and bathroom; this helps to drain part of the warm water pipes with the already built-up pressure in the water system, but since the water pump is now turned off, it won’t pump in any more water into the system only drain it out through the taps.

It is common practice to keep all faucets open when the water heater and system are drained and ready for winter storage or if there might be a chance of freezing temperature to prevent any build-up of pressure in the system since when water freezes, it expands.

Keep all faucets open when there is a risk of freezing to prevent pressure build up in the water system.

3. Open the water heater drain valve.

First, open up the water heater and cold water pipe drain valve; in my motorhome, it is located in the picture below to the bottom left of the heater. This is the valve I open first in the video above. When doing this, keep an eye out for how much water drains underneath your motorhome, RV, or caravan. Make sure it corresponds with the size of your water heater to ensure that you have drained the water heater.

It would help if you placed a container underneath your motorhome to measure the amount of water coming out. If you dont have a container available, at least make sure that it looks like the right amount and that it’s nothing wrong.

An example is when I first tried to drain my water heater, and no water came out underneath the motorhome. Something was wrong; it turns out that a previous owner plugged the drain pipe. So, of course, I could not drain the water heater without removing the plug that some previous owner put there for some reason.

After ensuring a reasonable amount of water comes out from the heater, you can open the warm water pipe drain valve if you have one; this is the second valve I opened in the video above, the yellow one.

Be aware that the valves can look very different in each motorhome, RV, or caravan. Still, the principle is the same look through my diagrams and look at your water system I am sure you will figure out your water system with that information. You can always double-check in your warm water heater manual.

Be aware that the valves can look very different in each motorhome, RV, or caravan.

Maybe you have bypass valves and want to bypass the water heater after you have drained it; in that case, those should be situated as in the diagram below.

Great, you have learned that you should drain your water heater and your water system if you don’t intend to use it within two weeks to avoid bacterial growth, algae, stale water, or a frozen water heater and how you should drain it.

If you want to learn how to fill up the water heater correctly at the beginning of your next trip and not to start the water heater empty and damage it, you should check out my other article, where I go through how you know that your water heater is full and how you fill it up.

Rikard Adamsson

Hello! My name is Rikard Adamsson; I am the creator of Motorhomeking.com. I live full-time in my motorhome, and right now, I am traveling through Europe the right way, without campsites; yes, wild camping and being off the grid works excellent even in a real beauty from 1996. I have done a lot of rebuilding and upgrades. I am happy to share my experiences with everything regarding motorhomes, RVs, or caravans with you here at motorhomeking.com.

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