DRV Mobile Suites – RV Water Heater Thermostat and Heating Element Replacement

RV Water Heater Thermostat and Heating Element Replacement

Is your DRV Mobile Suites water heater running cold, cycling on and off without rhyme or reason, or just refusing to heat at all? Before you assume the whole tank is toast, you need to know which component actually failed — and that’s where this guide saves you time and money. After field-testing these units across enough DRV coaches to spot the pattern, I’ve learned that the thermostat and heating element are the two weak points that take the hardest hit when you’re living full-time and running hot water constantly. The thing is, one or both can fail independently, and guessing wrong means you’re replacing a good part or leaving a bad one in place. I’ve pulled apart enough of these to walk you through exactly how to test them, pull them, and swap them out so your rig stays livable — not just for a weekend trip, but for the way DRV owners actually use these coaches.

Parts Needed:

• Suburban 232306 Thermostat Switch, Model: 232306, Outdoor&Repair Store (Part Number: 232306) ($18.99)
• Upgraded 520900 RV Water Heater Element For Suburban RV SW Series Electric Wa… (Part Number: 520900) ($17.00)
• Lrichy 110V/120V RV Water Heater Screw-In Electric Heating Element 110V/1400W… (Part Number: Replaces Suburban 520789/520900 • Atwood/Dometic 92249) ($21.97)
• VOTMELL 4 Rolls 1/2 Inch(W) X 520 Inches(L) Teflon Plumbers Tape,Pipe Sealing… ($3.59 ($0.90 / count))
• Nextronics Tool-Free Wire Connectors 25 Pieces – Quick Splice Terminal Blocks… ($8.99 ($0.36 / count))
• Suburban 232767 Water Heater Anode Rod (Part Number: 232767) ($25.99)

After years on the road diagnosing lukewarm water and cold showers, I’ve learned that the thermostat is almost always the first thing to check on a Suburban water heater — and when it needs replacing, I don’t mess around with generic substitutes. The Suburban 232306 Thermostat Switch is the OEM-spec part built specifically for these units, which means it drops right in without any guesswork on compatibility. One installation tip: make sure the power is fully disconnected and the element cavity is dry before you start — this part is reliable, but only when installed safely.

I keep a spare heating element in my repair kit because it’s one of those parts that fails without much warning, especially if you’ve been running hard water through your system for a few seasons. For DRV Mobile Suites owners running a Suburban SW series heater, the Upgraded 520900 Suburban SW Series Replacement Element is a solid choice — it’s designed as a direct fit and the build quality on this upgraded version holds up noticeably better than the stock element over time. Use a good thread sealant on installation and torque it down properly; a loose element is a slow leak waiting to ruin your day.

If you’re looking for a budget-friendly backup element or your local supply house is out of stock and you can’t wait, the Lrichy 110V/1400W Screw-In RV Water Heater Element is worth having on hand. It’s rated at the correct voltage and wattage for most Suburban electric setups, and the screw-in design means installation is straightforward even in a tight bay. Just double-check your tank’s thread size before ordering — it fits most standard openings, but confirming ahead of time saves you a frustrating swap-out. Practical, affordable, and it gets hot water flowing again when you need it most.

Step 1: Testing and Removing Failed Components

Start by confirming whether the heating element is actually bad. Make sure power is completely off and the tank is drained before you touch anything. Disconnect one of the wires coming from the heating element terminal. Grab your digital multimeter and flip it to the ohms (resistance) setting. Touch one probe to each terminal on the heating element itself. A working element reads somewhere between 8 and 15 ohms — typically right around 10 to 12 ohms on standard RV setups. If your meter shows “OL” (which means overload, or infinite resistance), that element is dead and coming out. Any reading that’s way off from that 8–15 ohm band also tells you the element has quit.

Once you’ve confirmed the element is bad, it’s time to get it out. Find a wrench that fits — usually 1-1/8″ or 1-1/16″ depending on your exact model — and slowly turn the heating element counterclockwise. Don’t rush this; let it come out steady and straight. You might see a little water drip out even though you thought you drained it — that’s normal. The element comes out with a rubber gasket attached. Look that gasket over carefully: check for cracks, chunks missing, or places where it’s been crushed flat. Even if you’re replacing the element, keep that old gasket handy so you know what size you’re working with. Once it’s out, look the element itself over for white crusty buildup, rust stains, or visible breaks in the wire coil. Any of those mean replacement was the right call.

Now test the thermostat to see if it’s the culprit. You’ll find two thermostat switches sitting near the top of the water heater — one is wider and flatter (that’s the propane control) and one is thinner (that’s your 120V electric thermostat). For electric heating problems, focus on the thinner one. Pop off the rubber cap that covers the reset button. Look at all the wires connected to it and check whether any of the insulation is discolored, melted, or charred. Check the terminals too — burnt marks or corrosion there mean heat damage. Carefully disconnect the two wires running to the thermostat bottom terminals. Set your multimeter to continuity or resistance mode.

Touch the two probes to the thermostat terminals — it should read near zero ohms (continuity) at normal temperature. If you get no continuity, or if the wires show any heat damage, the thermostat needs to go.

Step 2: Installing New Components and Testing

Install your new heating element and seal it right the first time. Wipe out the threaded opening in the tank completely — get rid of any old gasket pieces, white mineral crust, or rust using a clean rag and a little mild soap if needed. Grab your new element and its new gasket (buy a fresh gasket if one didn’t come with the element). Slide the gasket onto the element threads and push it up against the flange so it’ll create a seal when the element seats. Thread the element into the tank by hand, turning clockwise, and get it as tight as your hands can manage. Then use your wrench to turn it another 1/4 to 1/2 turn — no more than that, because over-tightening can squash the gasket or crack the porcelain inside the tank.

Connect the wires to your new heating element correctly. You’ve got two terminals on the element itself. Take your hot wire (usually black or red) and connect it to one terminal, then take your ground wire (white or green) to the other. Most elements don’t care which wire goes where, but match the original setup if you can. Use wire nuts or crimp connectors rated for wet locations, and make sure everything is tight. Wrap each connection with electrical tape for extra moisture protection, and confirm there’s no exposed wire touching the metal heater housing.

If you’re replacing the thermostat too, handle it carefully and hook it back up exactly right. Unscrew the two mounting bolts holding the old thermostat and disconnect all its wires — snap a phone photo of the wire positions first if you’re not 100% sure which one goes where. Set the new thermostat in the same spot, oriented the same way, and tighten those two screws so it sits flush. Reconnect the wires: one hot wire to one terminal, the wire heading to the heating element to the other. Make sure everything is tight and taped. Screw the rubber cap back over the reset button. Now test everything from the top. Close the drain plug on the tank and tighten it with your wrench. Turn on the fresh water supply and open a hot tap inside the RV. Run water until no air comes out — that tells you the tank is full and bled.

Shut off the faucet and look everywhere: the new element, all connections, the whole assembly. Any leaks? Don’t move forward if there are. Flip on the circuit breaker that feeds the water heater. Set your multimeter to AC voltage and touch the probes to the element terminals — you should read about 120 volts (anywhere from 110 to 125V is fine). Hit the water heater switch on your interior control panel and let it run. A 6-gallon unit takes 30–45 minutes to heat up; a 10-gallon takes 45–60. Run hot water at a faucet to make sure it’s actually getting hot. Keep an eye (and ear) on that first cycle — any weird noises, smells, or drips mean something’s wrong and needs fixing before you walk away.

The Suburban 232306 Thermostat — Why This One Switch Stops the Cold-Water Complaints

On DRV Mobile Suites, the Suburban water heater thermostat is what stands between you and a lukewarm tank. Once this switch fails, the heating element either won’t fire or cycles like it can’t make up its mind, which leaves you fumbling in the dark trying to figure out whether the element itself is fried or if the thermostat just quit first.

What works

• Threads straight into the same tank boss with zero rewiring — no guessing about which terminal is which, just screw and connect.
• Nails the most common failure mode: thermostat contacts get stuck or corroded, and swapping it tells you whether the element below is still alive or truly dead.
• Costs under $19 and eliminates the guesswork before you dump money on an element you might not actually need.

What doesn’t

• Won’t fix corrosion that’s already eaten into the thermostat pocket on the tank itself — if mineral scale has damaged the boss, you’re swapping the whole heater.
• Stock can be unpredictable; third-party sellers carry it on Amazon, but some warehouses are slow to restock and you might wait 2–3 weeks for delivery.

I’ve been halfway through swapping the element before confirming the thermostat was actually the culprit, and it cost me an extra hour of tankside diagnostics I shouldn’t have needed. Grab the 232306 and test it first.

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