
Tankless RV Water Heater
Tankless RV water heaters … hot water for as long as your propane, 12 volt power, and water supply lasts …
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Just visiting the wonderful agricultural town of Paso Robles in California’s Salinas River valley where a customer has a perfectly operating 10 gallon suburban water heater, but one significant safety feature has failed. The temperature and pressure relief valve is seized.
This device commonly called a TPR valve releases pressure inside the hot water tank if the temperature reaches near boiling point or internal pressures reach 150psi. Without this device functioning properly, the tank would rupture. The rupture could cause damage with leaking water, or worse, flying debris could damage the interior of an RV with possible injuries from scalding water and other physical injuries.
The relief valve is usually easy to remove. Sometimes a special tool is needed, like the Camco temperature and pressure valve remover tool shown below and available on Amazon.
This time, the old relief valve is rusted in place. Lifting the leaver usually releases water, sometimes scalding water so be careful, but in this case the relief valve is stuck closed. I tried everything possible. I used the Camco RV water heater valve removal tool, a breaker bar, an impact wrench, plenty of PB Blaster, even applying heat. Over several days of patiently working on a strategic removal of this frozen valve finally pronounced this entire RV water heater fully redundant. This water heater has lost its final safety relief mechanism and should not be used.
This customer is now facing the replacement of the current 10 gallon Suburban water heater or consider another brand.
What are the options?
The customer has decided to replace the old water heater, and there are quite a few options available.
Purchasing items using the provided Amazon links may generate a small commission to Happy Campers RV Repairs which provides income for maintenance of this website. Thank you in advance if you do proceed to purchase using these links.
One option is to buy the exact replacement of the existing Suburban 10 gallon RV water heater. This is usually the easiest choice. There might be slight variations in the location of plumbing, wiring, and propane connections, and the cost can sometimes be lowest of all options.
Something to consider is that the Suburban RV water heater has a steel water tank. This requires the changing of an anode rod which protects the steel tank from corrosion. Dometic brand water heaters are more expensive, but the aluminum tank does not require the yearly check of the anode rod.
What about a tankless water heater in an RV?
Tankless means unlimited supply of hot water. Normal RV water heaters carry between six gallons and 10 gallons of water. The water is heated and stored within a tank in the appliance and remains instantly available. But a 10 minute shower will easily drain the hot water, the incoming cold water cannot heat quickly enough. The shower becomes a much colder experience. Even switching both propane and electric heating on at the same time won’t keep the heating up enough for a hot shower, once the tank is depleted. Tankless RV water heaters heat the cold incoming water as it passes through a burner. Heating is almost instant, perhaps a few seconds slower than stored hot water, but hot water is available for as long has you have water and power. In this case, power means, 12 volts DC electricity and propane.
Tankless RV water heaters don’t need to heat a whole 6 or 10 gallons of water at a time. The tankless RV water heater also does not need to keep water hot for hours or days at a time until it is needed. Normal RV water heaters consume energy several times a day whether you are using hot water or not. Tankless water heaters don’t operate until the hot water faucet is turned on.
You can also vary the temperature of the water with a tankless RV water heater. If you want really hot water, just select the temperature on the wall mounted thermostat.
Tankless water heaters are also great for reducing weight in an RV. The weight of water in a 10 gallon heater is 80 pounds. A tankless heater retains only a small amount of water.
Installation?
While the tankless RV water heater manufacturers have made it as easy as possible to convert from an existing storage RV water heater, there is extra work required to install the thermostat and shutoff switch. This is an attractive electronic switch which is wall mounted somewhere inside your RV.

Ideally the control panel might be mounted in the bathroom next to the shower, or in the kitchen next to the kitchen sink. In my experience I have had one installation of the remote switch where it was very easy and took about 20 minutes to mount this switch right next to the water heater at the door entry. Another installation took over an hour and a half to track wiring from the water heater to the remote switch location on the bathroom wall.
Another challenge I have had is mounting some extra framing to properly locate the new tankless heater’s door. It was basic handyman stuff, but just be aware that the retrofit might be a little more time consuming than first estimated.
Prices of RV tankless water heaters are dropping with consumer demand. Where the tankless heater was nearly twice the price, the market is almost matched between the technologies.
I have just noticed the new Furrion brand RV tankless water heater is on the market. This price of this model includes the price of the cover door. An option in the Girard brand, and others.
Choose your replacement RV water heater from this list provided by Amazon …
Purchasing items using the provided Amazon links may generate a small commission to Happy Campers RV Repairs which provides income for maintenance of this website. Thank you in advance if you do proceed to purchase using these links.
Can I save energy with an RV tankless water heater?
Stored hot water heaters keep six or ten gallons of water ready and hot for when you turn on the hot water faucet in your RV. These water heaters are well insulated and depending on your level of hot water use, may only consume electricity or propane two or three times a day to keep the water in the tank heated.
Tankless water heaters only heat the exact amount of hot water you use which could save your energy. If you use a lot of hot water just because it is endless, then you might match or exceed the energy usage compared to stored hot water.
Will an RV tankless water heater save on electricity?
Most tankless water heaters for RVs use only 12 volt DC electric and propane. If you normally have your RV water heater switched to 120 volt AC power, then you will certainly save on your electricity bill. Tankless water heaters do consume propane for heating, so if you use a lot of hot water, you will increase your propane consumption.
Are than any downsides to tankless water heaters?
One of my customers stopped using the hot water and said the newly installed tankless water heater does not work. After investigation, I found the on/off switch on the control panel was off. Switching back to ‘ON’, I turned the hot water faucet to on in the kitchen and hot water began to flow. The customer then that it does not work in the shower.
So I tried the shower head and turned the hot water faucet fully on. No hot water! I removed the shower head and ran the hot water again. The hot water began to flow!
The reasoning for this is that the tankless water heater measures the flow of water before igniting the heating. The old shower head restricted the flow of water to a point where the tankless heater would not start. The customer just needed a less restrictive shower head to bring hot water back into the shower.
Tankless water heaters specify the amount of water pressure and volume required to run the heating. Check your water pressure before considering to purchase an RV tankless water heater. If it is very low, you may need to find ways to increase your water pressure before installation.
2 Comments on “Tankless RV Water Heater”
Zachary Tomlinson
I never knew that a tankless water heater can give you instantaneous hot water whenever you need it! My friend plans to travel around the country once the pandemic dies down for a bit. I think he should try investing in a water heater for his RV during cold weather!
Alan ONeill
Hi Zachary, in the field, I have noticed a few complaints with tankless water systems. This mainly revolves around deficient water pressure. If the water flow through the tankless water heater is too slow, the heater will not activate, or it will supply hot and then cold water during a shower. This is easily compensated by have some water in your onboard fresh water tank and switching on the fresh water pump. Another problem occurred when a customer fitted a special water saving head to their RVs shower. This particular head reduced the water flow to a point where the heater would not activate. The customer replaced the shower head and received continuous hot water again.