Alde RV Water Heater Problems
The Short Answer: Alde is a hydronic boiler with a small DHW cylinder — not a 6-gallon Atwood. Cold showers with hot glycol mean the mixing valve or summer/boost settings. No heat and no hot water mean 12 V, LP, air in the glycol, or an overheat lockout. Bleed, fill, photograph the panel. Smell propane, shut the bottles.
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Search Intent & The Real Problem
The control panel says Alde. The shower died at a dump station. Search results invent an Atwood ECO reset. Wrong machine. Alde 3010 / 3020 Compact / 3030 (Truma owns Alde now) heats glycol that runs convectors and a potable heat exchanger. nuCamp, T@B, many Euro vans, some Winnebago and Interstate bays. Airstream with a door badge that is not Alde is Airstream troubleshooting. Atwood/Dometic tank: Atwood. Truma AquaGo on-demand: AquaGo. This page is Alde hydronic.
What other guides get wrong
They paste Suburban Phase 3 board resets onto an Alde. There is no DSI tank ECO in the same place. They vinegar-flush the potable side as if it were a glass-lined 6-gallon. They mix Century blue silicate glycol with pink G12++ / Alde-Truma fluid and then wonder why aluminum stubs rot. They skip the mixing valve, so a healthy boiler gets a new pump. And they still describe cracking LP flares.
Step-by-Step Troubleshooting
Step 1: Read the panel. Alde is not an Atwood.
| What you see | What it actually is | Go here if you are wrong |
|---|---|---|
| Alde color panel, shower icon, glycol / water temps in service | Hydronic boiler + DHW cylinder | Stay |
| Atwood / Dometic on an exterior door | 6- or 10-gallon DSI tank | Atwood |
| Truma AquaGo | RV tankless | AquaGo |
| Suburban SW6 / SW10 | Steel tank, anode | Suburban gas |
| Interior switch, red fault LED, no Alde screen | DSI lockout | RV fault light |
- What to look for: Model on the boiler jacket (often under a bed or in a wet bay). Photograph the panel: shower icon off / half / boost, summer vs heat+water, any red overheat or low-battery message. Glycol level in the expansion tank — between the marks when cold.
- Required tools: Flashlight, phone camera.
Step 2: 12 V, LP, potable water, then glycol
| Check | Pass | Fail |
|---|---|---|
| Coach battery at the boiler | ≥12.0 V running; 12.6 V rest is healthy. Alde browns out under ~10.8–11 V | “Faults” that are actually voltage |
| LP bottles + stove | Other appliances light | Supply, not the Alde |
| City water or demand pump, bypass off | Stream at a hot faucet | Winterize / bypass still on |
| Expansion tank glycol | Level in range, correct color (do not mix blue silicate with pink OAT) | Air, leak, or wrong fluid |
| 120 V electric element option | Shore or generator actually on if you selected electric | Dry-fire risk if potable is empty |
- What to look for: Three-valve bypass left in winterize. Empty fresh tank. Pump that never reaches Alde activation. Electric selected on a drained exchanger — turned on without water.
- Required tools: Voltmeter, the plumbing diagram on the bay.
Do not crack an LP flare. Air after a bottle swap is a licensed or dealer LP procedure, not a closet purge.
Step 3: Settings that fake a dead water heater
- What to look for: Shower function off (heat only). Summer mode on when you wanted space heat, or the reverse. Boost not used when you need a short 30-minute DHW bump. Pump on continuous so the boiler never prioritizes the cylinder. Service screen: glycol hot (often 140–180°F class) and water still sitting at 80°F = mixer or potable flow, not a dead burner.
- Required tools: The Alde manual for that panel generation.
Mixing valve (nuCamp and cousins): old black cap toward + for hotter mixed water; newer red cap counterclockwise typically richer hot — confirm the “H” / “C” stamps. A mixer on cold is a healthy boiler and a tepid shower.
Step 4: Overheat, air, and ignition — look, do not rebuild
- What to look for: Red overheat after a fill or a steep grade: air in the glycol. Bleed at the boiler and the high-point convectors per the coach diagram, then a 12 V power pull for several minutes so the control reboots. Gurgling that never dies is still air or a pump speed too high. Click / no fire: LP, 12 V, or combustion air — do not keep sparking. Lights then dies: RV fires up then goes out as physics. Delayed bang: shut bottles. Fan or flue fault: do not fire it (CO).
- Required tools: Bleed key / screwdriver the manual calls for. Bottles closed for a spark look. Ears, not wrenches on gas.
Yellow flame, soot, or a headache: shut it down. Exhaust that smells like fuel is tankless-class exhaust gas in a tight bay.
Step 5: Glycol leak vs potable leak vs T&P
- What to look for: Pink or blue fluid at hose stubs, convectors, or the expansion tank = hydronic leak (corroded aluminum stubs are a known Alde/Truma service). Clear water at a domestic fitting, drain, or T&P = potable. T&P dribble on a small cylinder after a city-water fill is often expansion — RV T&P. Typical relief 150 psi / 210°F. City static over ~80 psi wants a regulator. Never cap it. Water at an exterior door on a tank coach is RV leaking outside, not Alde glycol.
- Required tools: Paper towel. Bottles off. No Flex Seal on a pressure vessel or a glycol hose.
A freeze-split potable exchanger is replacement, not epoxy. Same winter crime as tankless after freeze.
When DIY Ends: Calling a Licensed Pro
You may set the panel, fill glycol to the cold mark, bleed published air points, confirm 12 V and LP at other appliances, and adjust an accessible mixing valve. Stop at a propane smell, delayed ignition, gas-valve work, a glycol leak inside the cabin, repeating overheat, and any 120-volt element cover. A mobile RV tech who knows Alde / Truma fluid and stub connectors beats a fifth spark into a wet bay.
Frequently Asked Questions
Q: Why is my Alde water heater not making hot water? A: Shower function off, mixing valve on cold, bypass still in winterize, low 12 V, empty LP, air in the glycol, or an overheat lockout. Alde is not an Atwood tank. Read the panel.
Q: Why does the Alde show overheat or gurgle? A: Air in the glycol loop is the usual crime after a fill or a steep climb. Bleed the published points, restore glycol to the cold mark, then reboot 12 V. Repeating overheat is a tech, not a third bleed with the burner firing.
Q: Is pink fluid on the floor a water-heater leak? A: It is glycol from the hydronic loop until proven otherwise. Shut the boiler down. Potable leaks are clear water at domestic fittings or the T&P. Do not top the expansion tank with water and keep camping.