Alde Water Heater Not Working: RV Fixes
The Short Answer: Alde Compact 3010 / 3020 / 3030 is a hydronic boiler with an 8.5-liter DHW jacket, not a 6-gallon Suburban. No hot water is 12-volt brownout, glycol low or air-locked, LP off, electric elements not selected, Hot Water Ignore, continuous pump, or a panel lockout. Do not keep clicking gas with a propane smell. Fill glycol, power, then fuel — in that order.
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Search Intent & The Real Problem
The shower died. The Alde touch panel is blank, throwing Gas failure, or the coach is ice and the faucets are too. This is glycol in a closed loop that also wraps a small stainless DHW tank. It is not Atwood DSI and it is not Truma AquaGo on-demand. US coaches that carry Alde are high-end imports, some Nucamp / European builds, and the odd luxury fifth-wheel. The coach brand does not pick the part. Wrong Suburban board in an Alde bay is how harnesses melt.
Sister bays: Truma AquaGo, Girard tankless, Airstream, Suburban on gas. This page is Alde.
What other guides get wrong
They paste Suburban ECO resets onto an Alde. There is no tank ECO in the same place. They tell you to “just add water” to the expansion tank — that is glycol, Alde-specified, not hose water and not green automotive dump. They skip 12-volt: a panel that “randomly” dies at night is often a tired battery, not a gas valve. And they leave Hot Water Ignore or continuous pumping on, then buy a boiler because the 8.5 liters never recovered.
Step-by-Step Troubleshooting
Step 1: Read the panel — blank vs a named fault
| What the 3020 / 3030 panel says (confirm your sticker) | Meaning | First move |
|---|---|---|
| Blank, no backlight | No 12 V, T3.15 A glass fuse, panel cable | Battery, fuse at the boiler |
| Low battery | Supply under ~10.8–11 V | Charge / converter. False faults follow brownout |
| Gas failure | LP not lighting | Bottles, regulator, one trial, then licensed |
| Overheat red fail / Overheat glycol | Boiler body over ~95 C, or red sensor open | Bleed, glycol level, pump. Cool 15 min |
| Fan failure | Combustion fan RPM | Exhaust, leaves, then motor |
| Heater not found / No match heater/panel | Bus between panel and boiler PCB | Cable, then licensed board |
| Window open | Optional window switch | Close the window; confirm the OEM loop is still on the terminals |
| No message, radiators cold, DHW cold | Pump, air, settings, energy | Step 2 |
| Radiators warm, DHW cold | Hot Water Ignore, continuous pump, empty city water | DHW path |
- What to look for: Photograph the standby screen before you pull 12 V. Faults often show only on standby, not in the menus. Reset is 12 V off ~10 seconds — once after you fix the cause.
- Required tools: Phone camera, flashlight on the boiler fuse and the expansion tank.
Gas failure plus a propane smell is not a reset. Shut bottles.
Step 2: 12 volt, LP, and 120-volt electric — before parts
- What to look for: Coach battery / converter. Rest around 12.6 V; Alde boards get stupid under ~11 V. T3.15 A fuse at the boiler intact. Bottles open, regulator not icing, stove lights. Shore power: 120 V (US) or 230 V (EU) selected on the panel at 1 kW / 2 kW / 3 kW if you want electric. Load monitor set so the elements are not locked out. Gas will not fire with 12 V dead even if the bottles are full.
- Required tools: DC meter if you are qualified. Eyes on bottles and the electric icons on the panel. No union wrenches.
Alde LP is typically near 10–11 in. w.c. at the rating plate — confirm that plate. Manometer work is licensed. Do not crack a flare. Do not purge fittings.
Step 3: Glycol level, air, and the circulation pump
- What to look for: Expansion tank cold level about 0.5 in / 1 cm above MIN. Below MIN is how you buy an overheat. Pump symbol on the status screen when heat is calling. Pipes warm only a foot from the boiler = air. Gurgle in the tank after a fill is air — pump off a few seconds, then bleed at the OEM screws, then licensed fill pump if it will not clear.
- Required tools: Eyes on MIN/MAX. The coach bleed-screw map. Alde-specified glycol only if you are topping — not random hose water.
Do not run the boiler to “burn the air out” on a low tank. Overheat red fail after that is the red sensor doing its job. Cool it, bleed it, then one 12 V cycle.
Step 4: DHW jacket vs space heat — two different complaints
- What to look for: Hot Water Ignore on (panel will skip DHW recovery). Continuous pumping on (glycol keeps stealing heat from the 8.5 L jacket). Fresh-water pump / city fill / Nautilus bypass in winterize so no potable water reaches the jacket. Drain valve on the Alde left open after a freeze dump. Electric-only in January with 1 kW selected will make slow, short showers — that is math, not a failed boiler. Gas + electric together is how Alde recovers in the cold.
- Required tools: Panel menus. A hot faucet. Bypass diagram on the bay door.
Pink or sweet potable water is glycol through a cracked jacket. That is replacement, not a flush. Isolate drinking water and hire an RV tech.
Step 5: Freeze, leaks, and a boiler that is actually done
- What to look for: Stored with water in the DHW jacket and 12 V off — split stainless. Glycol puddle under the boiler, wet convectors, or a tank that will not hold MIN. Repeated Fan failure with leaves in the combustion air. PCB that died after someone plugged in 120 V with the Alde left on (classic blown T3.15 A, sometimes the board). Scale is not the Suburban-anode story; this is stainless plus glycol.
- Required tools: Paper towel. 12 V off. If the board is wet, it stays off.
A freeze-split Alde is replacement. Power the panel whenever there is water in the jacket. Drain the DHW side for storage the way Alde wrote it — that air cushion is also how the little tank survives city-water spikes.
When DIY Ends: Calling a Licensed Pro
You may photograph a fault, confirm bottles and 12 V, read MIN on the expansion tank, turn Hot Water Ignore off, and cycle 12 V once. Stop at a propane smell, Gas failure that returns, glycol in the potable water, a wet board, gas-valve work, and an overheat that will not clear after a proper bleed. A mobile RV tech who stocks Alde pumps, panels, and boilers beats a fifth lockout and a bay full of unburned LP. Wrong Truma or Suburban part in an Alde compartment is how you buy two heaters.
Frequently Asked Questions
Q: Why is my Alde water heater not working? A: No 12 V, a blown T3.15 A fuse, glycol below MIN or air-locked, LP off, electric not selected, Hot Water Ignore, continuous pumping, or a panel fault (Gas failure, Overheat red fail, Fan failure). Read the standby screen.
Q: The Alde heats the coach but I have no hot water. A: Turn Hot Water Ignore and continuous pumping off. Confirm city water or the demand pump is actually feeding the 8.5 L jacket, and that the Alde drain is closed. Radiators proving the boiler is alive does not prove DHW flow.
Q: My Alde froze. Will a reset fix it? A: A 12 V cycle clears an electronic lock. It does not fix a split DHW jacket or a cracked boiler body. If the bay was wet after a freeze, hire an RV tech and do not restore LP.