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Learning how to winterize your RV tankless water heater properly can prevent damage to the plumbing system from the winter season. If water pipes freeze, they can crack and cause problems down the line such as leaking, therefore it’s best to take precautionary measures and prepare your RV tankless water heater for winter.
So let’s get straight to the point and answer everybody’s question now that winter is on its way; how do you winterize an RV tankless water heater?
There are two ways of winterizing an RV tankless water heater, the first is by using compressed air and the second is by using RV antifreeze. Both of these RV tankless water heater winterization methods are effective at protecting the RV plumbing system from damage under freezing temperatures.
If you’re beginning the RV winterization process, you’ll need to include an effective winterization method for your plumbing system. So, let’s take a look at the two methods for winterizing an RV tankless water heater in a bit more detail.
How Do You Winterize an RV Tankless Water Heater with Compressed Air?
Winterizing an RV tankless water heater with compressed air is a simple and effective way of protecting the water heater from the cold. This is a process that can also be completed in just a few simple steps.
Step 1: Turn Off the Electrical Power and Gas Supply to the Heater
As a general rule, before the winterization process begins with your RV, it’s important to turn both the gas and the electrical power off. Turning the power and the gas off helps stop the water heater from trying to reheat any residual water.
Step 2: Shut Off the Water Supply and Allow the Water to Cool
After turning the water supply off, the water can be drained by turning on the faucets and shower, allowing the water to drain out. If the water heater has recently been in use, it’s best to wait an hour or so until the water has cooled to drain the system. This prevents boiling hot water from draining out, which I can confirm from personal experience, isn’t the wisest or safest idea!
Remember the gray, black, and fresh water needs emptying during the RV winterization process too. This can sometimes be forgotten, and there’s nothing worse than when spring camping season arrives, and you realize the RV toilet hasn’t been emptied, cleaned, or stored correctly during winter.
Step 3: Disconnect the Water Pipes
Before disconnecting the water pipes, make sure all the water has finished draining out. It’s a good idea to place a bucket underneath the tankless water heater to catch any leftover water and prevent spills. The inlet and outlet water connections will need disconnecting too before proceeding to use the air compressor to complete the winterization process.
Step 4: Use an Air Compressor
Once the air compressor has been adjusted to the correct settings, it can be attached to the water inlet. After the air compressor has been attached correctly, it is ready to be used and can be turned on. Using the air compressor for short bursts of time prevents any risk of too much pressure passing through the system.
You’ll know when the process is complete as the water will stop dripping out from under the unit.
Winterizing an RV water system with compressed air is a method trusted by many RV owners storing their RV away over winter. This method is broken down into simple steps in the video below that are both easy to understand and follow.
Some people prefer the compressed air winterization method for their water system as it avoids bringing RV antifreeze into their environment which can contain dangerous chemicals. Although RV antifreeze is non-toxic, it can still be harmful to immediate surroundings and is not safe around pets either.
How Do You Winterize an RV Tankless Water Heater with Antifreeze?
Using antifreeze to help winterize an RV tankless water heater has a bit of a bad reputation, and it’s right to be cautious when it comes to running antifreeze through your RV plumbing system. If antifreeze is used incorrectly to winterize a water heater, it may damage internal components and even void the warranty.
Before using antifreeze for water tank winterization, it’s crucial to check the RV manufacturer’s guidance and advice when it comes to putting antifreeze into the system.
If used correctly, however, RV antifreeze is an effective way to protect your water system in sub-zero temperatures and should be considered.
It’s also important to note, only non-toxic RV antifreeze such as those containing propylene glycol should be used to avoid any internal damage.
Step 1: Turn off The Electrical Power and Gas Supply to the Heater
Turning off any power or gas supply to the water heater will prevent the risk of the heater turning on and sending unwanted water through the system. As a general rule, always turn the power supply off when it comes to winterizing an RV tankless water heater, regardless of which method you decide to use.
Step 2: Shut off The Water Supply and Allow the Water to Cool
The water in the heater needs time to cool if it has been recently used, which can take up to an hour or so. Once the water has cooled, open up all faucets and allow the water to flow out. This is the quickest and most effective way of releasing both water and pressure, preparing the system for the addition of RV-specific antifreeze.
Step 3: Remove or Bypass Inline Water Filters
As using antifreeze can potentially ruin the water filter, it’s important to either remove the filter or use a filter bypass kit.
Step 4: Pump the Antifreeze Through the System
If using the popular method of an external hand pump to pump the antifreeze through the system, you can now attach the hose and start getting the antifreeze through the water pipes.
Open everything back up one by one, allowing any faucets or showers to run until you notice the pink antifreeze liquid flowing out.
Once the antifreeze has reached each water point in the RV, everything can be turned back off as the process is complete. Remember to repeat this antifreeze winterization process for sinks, toilets, and both exterior and interior hoses.
As you can see in the video, the water in any lines and tanks needs to be emptied, and the tanks need to be winterized for the cold season. Using RV antifreeze is an ideal method and if completed one step at a time, the process seems far less daunting!
How Do You De-Winterize an RV Tankless Water Heater?
If winterizing a tankless RV water heater using the antifreeze method, you’ll need to then de-winterize it ready for camping in the spring season. This is important as the antifreeze will need to be flushed out of the water system thoroughly before the water is safe to drink and use as normal. This can take a bit of time and effort but is an essential process that cannot be skipped.
The de-winterization process can only be completed when spring is on the horizon and temperatures have increased to above freezing. If the weather is still too cold, the water inside the pipes and heater may freeze which can cause damage if broken, and parts may need replacing.
Flush All the Antifreeze out from the System
If there’s a bypass valve on your RV tankless water heater, this needs to be turned on to allow the antifreeze to run through the system and out through the various water points such as faucets, showers, hoses, etc. Once connected to a water supply such as a city outlet or garden hose, each faucet can be opened one by one to clear out the antifreeze.
Turn the Water Supply off
Antifreeze tends to be a bright pink color, so it should be easy to notice when it begins to flow out of the system. It’s also easy to tell when the antifreeze has been completely drained out, as the water will begin to run clear. Once there are no further traces of pink in the water, the water supply needs to be turned off.
Take the Water Heater out of Bypass Mode
The tankless water heater will then need to be taken out of bypass mode. If the heater was not put into bypass mode, the heater will need to be flushed through and drained before putting a new water filter in.
Connect the Water Supply and Flush Again
The water supply can be reconnected and the system needs to be flushed thoroughly once more for several minutes to get rid of any trace of antifreeze. The last thing you want to be drinking is strange-tasting, pink water, so it’s best to be as thorough as possible when flushing the system through!
It’s also important to check the best method for draining and disposing of RV antifreeze, as some of the ingredients may be harmful to the environment.
The next stage of the de-winterization process of an RV tankless water heater involves sanitizing the system.
How Do You Sanitize an RV Tankless Water Heater?
Even if you didn’t use non-toxic antifreeze to winterize your plumbing system, sanitizing your water system is still important for removing any bacteria or mold that could have grown during the months in storage.
Although there are other ways of sanitizing a tankless water heater, the most popular method uses bleach. Bleach is great for cleaning away any potential bacteria or mold that may have formed over winter.
Measure the Bleach
The amount of bleach needed for sanitizing an RV tankless water heater is one-quarter cup of regular household bleach for every 15 gallons of water the tank holds. Once measured, combine the bleach and water together, mix and pour into the fresh water tank.
Fill the Fresh Water Tank
The fresh water tank then needs to be filled up with potable water, and all hot and cold faucets need to be turned on. Allow the water to keep running through until you notice the smell of bleach.
Allow Bleach Mixture to Sit for 12 Hours
Once the bleach can be smelled, allow the water and bleach mixture to sit in the fresh water tank and water pipes overnight or for at least 12 hours. This will help get rid of any bacteria build-up that may be sitting in the tank.
Drain and Refill the Water Tank
All of the water can then be drained from the system and the fresh water tank can be filled again.
Drain Until no More Bleach is Present
Drain the water out from the system until you can no longer smell any bleach. Once no more bleach can be smelled, the water should be ready for safe use again.
This video above is a great example of how to sanitize both the hot and cold water lines in your RV water system. Although the sanitization process takes a bit of time and isn’t the most exciting, it’s worth all the effort.
Having clean, safe and fresh drinking water in an RV is one of my top priorities, and the peace of mind sanitizing the water system brings makes all the effort worth it!
Not all RV tankless water heaters have antifreeze features that help winterize the heater, so it’s important to know how to best prepare your RV tankless water heater for those challengingly low temperatures. If you’re not sure which winterization method to use for your RV water system, my best piece of advice would be to take a look at the owner’s manual to make sure you choose the most appropriate method for your system.
By taking the right precautions and winterizing your RV and its components, you can rest safe knowing that come springtime, your RV will be ready to hit the road with no costly fixes or repairs from winter.