Forest River Impression – RV Water Heater Thermostat and Heating Element Replacement

RV Water Heater Thermostat and Heating Element Replacement

The Suburban water heater in a Forest River Impression sits tucked behind the galley, running on both propane and 120-volt electric — and that dual-fuel setup is exactly why a lot of owners either call a tech or end up chasing phantom problems for weeks. A bad thermostat won’t always announce itself loudly; instead, you’ll get erratic heating cycles, water that climbs past your setpoint, or an element that won’t shut down at all. The thermostat and heating element are separate failures with separate fixes, but they live so close to each other in the assembly that most owners treat them as one job — which is smart, because you’re already drained down and have the power disconnected. This guide covers both: how to test each component before you tear into anything, which ones actually need replacing, and exactly how to wire them back so you don’t trip a breaker or flood a compartment. The order matters. The wiring matters. The details in between matter more than any dealer checklist will tell you.

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 and more water heater headaches than I care to count, I’ve learned that the thermostat is almost always the first thing to check when your hot water goes cold. The Suburban 232306 Thermostat Switch is a direct OEM-fit replacement for most Suburban units, which means no adapter headaches and no guessing. It snaps in clean, the contacts are solid, and I’ve never had a callback problem after installing one. Just make sure you drain the tank and kill the breaker before you touch anything — this is a five-minute job if you respect the process.

I keep a spare heating element in my repair kit specifically because it’s the kind of part that fails at the worst possible campground, miles from any RV dealer. The Upgraded 520900 RV Water Heater Element for Suburban SW Series is an aftermarket upgrade that actually outperforms the stock element in my experience — better corrosion resistance and a tighter seal right out of the box. It’s designed specifically for the SW series, so fitment is straightforward. Use a fresh rubber washer, apply a little thread sealant, and torque it down firmly but don’t go gorilla on it or you’ll crack the tank fitting.

If you’re dealing with a non-Suburban unit or you just need a reliable universal option, the Lrichy 110V/1400W Screw-In Electric Heating Element is a solid budget-friendly pick I’d recommend without hesitation. At 1400 watts and built for standard 110V/120V RV systems, it heats efficiently without overtaxing your shore power or generator. The screw-in design makes installation straightforward — just match your thread size before ordering. I always flush the tank thoroughly before dropping a new element in; mineral buildup is what kills these things prematurely, so a quick flush now saves you another replacement down the road.

Step 1: Testing and Removing Failed Components

Begin by checking the heating element itself — whether it’s actually dead or just misbehaving. After you’ve shut off power at the breaker and drained the tank completely, disconnect one of the two power wires running to the heating element’s terminal posts. Grab your digital multimeter, flip it to resistance (ohms) mode, and touch one probe to each terminal of the element. A working element bounces back a reading somewhere in the 8–15 ohm range, usually clustering around 10–12 ohms for standard RV tank elements. If your meter shows “OL” (overload) or climbs off the scale into infinite territory, the element has burnt out and needs to come out. Anything that reads way outside that 8–15 window is also telling you the same story: time for a replacement.

Once you’ve confirmed the element is toast, grab the right wrench — usually a 1-1/8″ or 1-1/16″ depending on which water heater model you’re looking at — and begin loosening it from the tank. Rotate counterclockwise, slow and steady; don’t yank it. Some water will probably seep out even though you drained things earlier — that’s normal, just part of the residual sitting in the tank. The element will come free along with a rubber gasket. Look hard at that gasket: cracks, compression set, or any disintegration means it won’t seal again. Keep it for now as a size reference, but plan to swap it out for a fresh one. While the element is out, eyeball it for mineral crusting, rust streaks, or visible breaks in the heating coil itself — all physical proof you made the right call pulling it.

Now test the thermostat switches. You’ll find two of them clustered near the top of the water heater housing — look for one with a wider, flat conductor (that’s the 12V propane controller) and one with a thinner wire (that’s your 120V electric switch). If you’re dealing with an electric heating issue, focus on the 120V unit. Pop off the rubber cap that covers the reset button and scan the wiring for any red flags: discoloration or melting on the insulation, charred terminals, connections that have gone loose. Disconnect the two power wires that feed into the thermostat’s bottom terminals. Switch your multimeter to continuity mode or set it to a low-resistance scale.

Touch the probes to both thermostat terminals. In normal operating mode, you should see continuity — a reading hovering near zero ohms. If the meter shows open circuit (no continuity) or if the wiring shows heat damage under the insulation, that thermostat is done and needs replacing.

Step 2: Installing New Components and Testing

Put the new heating element in place with a clean seal. Wipe out the threaded port on the tank using a dry rag, scrubbing away any leftover gasket shreds, mineral deposits, or corrosion. If you need to, use mild cleaner to cut through buildup, but make sure everything is dry before you start threading. Take your new heating element and slide its gasket (new one, or included with the element) onto the threads and snug it up against the flange. Start the element into the tank opening by hand, twisting clockwise. Get it hand-tight before you touch it with a wrench. Once you can’t turn it by hand anymore, give it an additional 1/4 to 1/2 turn with the wrench — stop there. Over-tightening will squeeze the gasket to failure or crack the porcelain tank lining inside.

Wire up the new heating element following the original wiring diagram. Spot the two terminal posts on the new element. Take the hot wire (usually black or red coming from the RV’s electrical side) and attach it to one post; connect the ground wire (white or green) to the other. Most elements don’t care which is which — they’re non-polarized — but copy whatever the original installation looked like. Use wire nuts or crimp connectors rated for wet, outdoor environments. Make every connection tight. Wrap each joint with electrical tape to guard against moisture creep. Confirm there’s no bare copper showing and that nothing can short out against the metal water heater housing.

If the thermostat is getting replaced too, pull the old one off by disconnecting all its wires and removing the mounting screws (two, usually) that hold it to the bracket. Position the new thermostat in the same spot, same angle, as the original. Screw it down so it sits flush — proper seating matters for temperature sensing. Reconnect the wires to the new thermostat’s terminals exactly as they were on the old unit. If you’re not certain, snap a photo of the old thermostat before you disconnect it so you have a reference. The hot supply wire goes to one terminal, the wire feeding the heating element goes to the other. Ensure both connections are tight and fully insulated. Slip the rubber reset button cap back on.

Run through a full system test before you call it done. Close the drain plug on the tank and tighten it down with your wrench. Switch on the fresh water supply to your RV and crack open a hot water faucet inside. Let the water run until it flows steady and clear of air bubbles — that means the tank is topped off and purged of air. Shut the faucet. Inspect the new element and all wire connections for any leaks or drips. Flip the circuit breaker for the water heater back on. Using your multimeter in AC voltage mode, touch the probes to the element’s terminals — you should read right around 120 volts (anything from 110 to 125V is fine). Activate the water heater from the interior control panel. Sit and wait: 30–45 minutes for a 6-gallon unit, 45–60 for a 10-gallon, until the heater reaches full temperature. Run a faucet to confirm hot water is flowing. Watch that first heating cycle for any odd sounds, smells, or puddles that shouldn’t be there.

The Suburban 232306 Thermostat — Why This One Part Stops the Cold-Water Showers

The Suburban 232306 thermostat sits as the switch between nobody getting a hot shower and actually having water hot enough to wash with. Once this switch fails, the heating element spins up without a signal to cut it off — cycling erratically or running full-bore, which leaves you with tepid water or a tank too hot to touch the exterior housing.

What works

• Temperature holds steady — no more wild swings from scalding to frigid mid-shower.
• The element actually shuts down once the tank reaches your setpoint instead of running itself ragged.
• Bolts straight into a Forest River Impression frame without hunting for adapters or bending brackets.

What doesn’t

• Amazon’s inventory on this exact part number shifts — clones and repackaged units show up regularly instead of genuine Suburban stock.
• You have to drain the tank and contort into the tight space behind the water heater to reach it — this isn’t a five-minute swap if you’ve never dug in before.

I second-guessed swapping just the thermostat on my first Forest River call because the element had obviously failed too, and I almost bought both parts blind without testing which one was actually the culprit. Grab the Suburban 232306 thermostat here—but test the element resistance with a multimeter before you assume that’s dead too.

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