My Big Fat Water Heater @ Liberty Coach

[MyPrevost]

Well, it’s all sorted now—I’ve got a new water heater.

We arrived at Liberty Coach on Tuesday and spent the night in their lot. The place had reliable power and a tall, barbed wire fence, so we felt secure being at the birthplace of our coach.

Our service manager, Bill Daughtery, was incredibly knowledgeable and professional. He answered every question we had about our coach. While he agreed that the water heater needed replacement—evidenced by its 2-inch bulge— the exact cause wasn’t immediately clear.

While at the factory, we also decided to address two other issues: a broken mirrored lucite cabinet handle and an inaccurate left-side ammeter. Although the water heater was replaced by Wednesday, they needed an extra half day to finish up the work. We took the opportunity to visit Chicago and do some sightseeing.

So, what caused the heater to fail besides its 13 years of service? Upon inspecting the remains, we found that the pressure relief valve was a type Bill hadn’t seen before. It was similar but not identical to the one on the new heater. Before the repair, the valve appeared to be functioning fine, so it wasn’t initially blamed for the tank’s bulge. It turned out that a previous owner had replaced the original pressure relief valve with a high-quality one rated at the same pressure as the tank itself—150 PSI. Unfortunately, the factory valve on the new unit was rated at 75 PSI, which was the cause of the bulge. Lesson learned.

We’re relieved that the old tank never burst or leaked. The new tank’s water is noticeably hotter, and after a few hours on the road, it was downright scalding from the exchanger heat. All is well now, and my wife is thrilled with the extended shower time.

I highly recommend Liberty Service. Bill is the go-to expert if you ever need advice.

[MyPrevost]

Fred,

Let me clarify that the tank’s failure wasn’t solely due to the water pressure relief valve.

I can almost guarantee that at some point, the accumulator tank (the blue one on the left side) had zero bladder pressure. As the water expanded, likely due to the higher temperatures from the engine coolant, there was no room in the accumulator tank for this expansion, which caused your water heater to bulge.

Somewhere along the line, someone missed the importance of addressing these small issues. It’s often the little things that can end up causing significant problems.

[MyPrevost]

Fred,

I want to clarify that the tank’s failure wasn’t solely due to the water pressure relief valve.

I’m certain that at some point, the accumulator tank (the blue one on the left side) had no bladder pressure. As the water expanded, likely due to the higher temperatures from the engine coolant, there wasn’t enough room in the accumulator tank for this expansion, which caused the water heater to bulge.

Somewhere along the way, someone missed the importance of addressing these minor issues. It’s often the little things that can end up causing significant problems.

My tank appears to have the original pressure relief valve installed by Liberty, which is rated at 175 PSI.

Do you think it should be replaced with a 75 PSI valve as suggested? There’s a 75 PSI valve listed as RV75, which might be targeted at the RV industry.

I don’t believe anyone replaced yours, Fred. It’s likely that it came that way when new.

It’s possible that the RV75 valve wasn’t available back in 1997, and that over time, industry standards evolved, leading to the development of a new pressure relief valve better suited for RV systems.

[MyPrevost]

From the Raritan Web Site:

If your water heater’s pressure relief valve is dripping, it could be due to several reasons. One common issue is that the rubber seal in the valve may have worn out over time. This part can be replaced with #WH3. The relief valves on Raritan water heaters are set to activate at either 75 PSI or 210° F. If the pressure or temperature exceeds these limits, the valve will open to release the excess.

For Raritan water heaters with heat exchangers that use engine coolant, ensure that some coolant is diverted through a bypass valve to prevent the water temperature from exceeding the relief valve’s limits.

If the pressure relief valve you’re seeing is rated above 175 PSI, it indicates that a higher-pressure valve was installed, which could be due to the system’s requirements. In a Liberty system, expansion is managed by the accumulator or expansion tank, provided the bladder pressure remains between 20 to 30 PSI. If this bladder pressure is lost, the system becomes closed, similar to a hydraulic system. In this state, any expansion due to heating will increase system pressure, and with nowhere else to go, the excess pressure might cause the relief valve to open. If a high-pressure valve like a 175 PSI one is installed, it will hold the pressure until it reaches a critical point, potentially causing the system to fail if the pressure builds up too much.

For more information, check the owner’s manual or contact Raritan Technical Support.

[MyPrevost]

From the Raritan Web Site:

If your water heater’s pressure relief valve is dripping, it could be due to several reasons. One common issue is that the rubber seal in the valve may have worn out over time. This part can be replaced with #WH3. The relief valves on Raritan water heaters are set to activate at either 75 PSI or 210° F. If the pressure or temperature exceeds these limits, the valve will open to release the excess.

For Raritan water heaters with heat exchangers that use engine coolant, ensure that some coolant is diverted through a bypass valve to prevent the water temperature from exceeding the relief valve’s limits.

If the pressure relief valve you’re seeing is rated above 175 PSI, it indicates that a higher-pressure valve was installed, which could be due to the system’s requirements. In a Liberty system, expansion is managed by the accumulator or expansion tank, provided the bladder pressure remains between 20 to 30 PSI. If this bladder pressure is lost, the system becomes closed, similar to a hydraulic system. In this state, any expansion due to heating will increase system pressure, and with nowhere else to go, the excess pressure might cause the relief valve to open. If a high-pressure valve like a 175 PSI one is installed, it will hold the pressure until it reaches a critical point, potentially causing the system to fail if the pressure builds up too much.

For more information, check the owner’s manual or contact Raritan Technical Support.

I firmly believe that anyone using a 175 PSI pressure relief valve should replace it immediately. The 75 PSI valve is essential for safeguarding the entire system, regardless of whether the expansion tank is functioning properly.

It’s impossible to determine the exact pressure that was reached in my tank or if the 175 PSI valve ever activated on its own. However, it’s clear that the pressure was significant enough to cause noticeable deformation of the tank. Even if the pressure was below 175 PSI, it was substantial, given that a 20-inch tank could experience around 55,000 pounds of force at 175 PSI.

Although my tank didn’t rupture, it did expand vertically by 2 inches. What’s remarkable is that the plumbing system managed to withstand the pressure without any leaks, which is quite impressive for plastic plumbing.

Additionally, there is a mysterious stain behind the heater that remains unidentified.

I wasn’t able to observe the heater replacement in person, so I handed my camera over to Bill Daughtery, who took the photos. I would have liked to be involved in the repair, but unfortunately, I don’t have a garage of my own. I do, however, envy John’s barn.

[MyPrevost]

Fred, what was it that made you aware of your water heater trouble. What was/were the telltale symptoms.

JIM

[MyPrevost]

Fred, what was it that made you aware of your water heater trouble. What was/were the telltale symptoms.

JIM

I owe thanks to Jim Elmore for his insight; he showed me the water heater in his 2000 Liberty when it was leaking. The main signs were the separation of the bottom outer cover and the fact that the entire assembly had lifted by about 2 inches. Normally, the tank stands 24 inches tall, but after the bulge, mine measured 26 inches. Given the risk of a leak, I decided it was best to replace the heater. The bulging condition had put significant stress on both the plastic and copper pipes.

[MyPrevost]

I have that same condition.

JIM

[MyPrevost]

Wow! Fred may have just saved you a lot of damage, before that darn thing explodes!

[MyPrevost]

While a split or fracture in the water tank is possible, an explosion is unlikely. Since the bulging of the tank is caused by hydraulic pressure, the pressure will drop almost immediately once a leak or crack allows it to escape. However, this doesn’t account for the water damage that may result.

If you have a tank that has bulged but is still holding water, the best course of action is to ensure that the accumulator tank has the correct bladder pressure and that the pressure relief valve is rated appropriately. As long as system pressures are maintained within the normal range of 40 to 60 PSI, the hot water tank should remain intact. So, Jim, if everything else is functioning correctly, there’s no need to worry excessively about the tank itself. However, if the accumulator tank cannot maintain the proper bladder pressure (which should be checked when the water system is at zero pressure with a faucet open), it should be replaced before you continue on your way.

[MyPrevost]

I’ve just replaced the bladder tank and the pressure relief valve. For now, I’ll live with the bulged hot water tank until it’s convenient to replace it. Raritan has informed me that they’re behind on production and won’t be able to fulfill orders for about two weeks.

With my schedule already overflowing as I prepare to head out on the road at the end of September, I’m not in a position to tackle the replacement just yet.

— Jim

[MyPrevost]

Probably a poor choice of words on my part. I meant that the tank might rupture and a lot of hot water down there wouldn’t be a pretty site.

[MyPrevost]

Your assessment is probably accurate in that if a seam were to split, it would likely create a considerable amount of noise, followed by a substantial rush of water. The point was to illustrate the issues related to having an excessively high pressure relief valve.

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