Suburban RV Heater Not Working on Gas
On this page (5 sections)
The Short Answer: When a Suburban works on electric but not on propane, the tank and plumbing are fine and the fault is on the gas side: empty or closed LP cylinders, low 12-volt battery voltage, an ignition lockout, a blocked burner tube, or a failed igniter, gas valve, or board. Check LP and battery, cycle the gas switch once to clear a lockout, and leave the burner parts to an RV technician.
How the gas side works
Most current Suburban water heaters (the SW and SW DE series) use direct spark ignition (DSI). When you turn on the gas switch inside the coach, a 12-volt board opens the gas valve and sparks the burner. If it does not sense flame within a few tries, it locks out and, on most models, lights an indicator on the switch. Older pilot models (for example SW6P) light a standing pilot instead and depend on a thermocouple. Check the model on the label inside the outside access door.
Sort it by what you hear and see
Stand near the outside access door while someone turns on the gas switch.
| What happens | Likely cause | Who handles it |
|---|---|---|
| Nothing at all, no click, no light | Switch off, fuse blown, very low battery, or a tripped safety cutoff | Owner checks switch, fuse, and battery; tech for the cutoff |
| Clicking or sparking, no flame | No LP to the heater, air in the line after a cylinder change, or a gas valve that does not open | Owner checks LP; tech for the valve |
| Flame lights, then goes out after a few seconds | Flame not sensed, dirty or misplaced electrode, weak LP pressure, strong wind | Tech |
| Lockout light on after several tries | Board gave up after failed ignition | One switch cycle, then tech |
| Gas works sometimes, worse in cold weather | LP regulator icing, low cylinder | Owner checks LP level; tech for regulator |
What you can check safely
- LP supply. Confirm the cylinder valves are open and the cylinders are not empty. Try the stove: if the stove lights, propane is reaching the coach. If nothing propane-fired works, the problem is supply, not the water heater.
- 12-volt power. DSI boards need steady battery voltage. If your monitor panel shows a low battery, charge it or plug in, then try again.
- The tank is full. The heater should have water in it before it fires. Open a hot faucet until water flows without sputtering. Check that the winterizing bypass is in the normal position.
- One lockout reset. Turn the gas switch off, wait a moment, and turn it on again. After a cylinder change, it may take a few tries to clear air, but if it does not light after the reset, stop and arrange service.
- A visual look from outside. With the heater off and cool, look through the access door for insect nests, spider webs, or debris around the burner tube opening, and for soot. Note what you see for the technician.
Turn the electric switch off while you troubleshoot gas so an empty tank cannot be heated by the element.
What the RV technician will check
An RV technician typically checks LP pressure at the appliance, cleans the burner tube and orifice (insects and spiders are a well-known cause of no-light or a yellow, lazy flame in RV water heaters), and inspects the electrode for cracks, gap, and position. They will test the board’s output, the gas valve, and the thermal cutoff and high-limit switches, which shut off the gas if the heater has overheated. Most of these are part replacements; none involves replacing the tank.
Air in the propane line after a cylinder swap usually clears on its own through a few ignition attempts. Loosening fittings to bleed it is not an owner task; see why you should not purge the gas line yourself.
Related pages: Suburban water heater not working on electric, how to reset a Suburban water heater, and RV water heater fires up then goes out.
Frequently Asked Questions
Q: Does electric working mean the tank is fine? A: It means the tank holds water and the electric side is working. The gas and electric sides have separate controls, so a gas fault does not point to the tank.
Q: Why does my Suburban lock out more often after storage? A: Insects and spiders build nests in burner tubes during storage, which block the gas-air mixture. Many RV owners have the burner area inspected at the start of each season.
Manuals and supporting references
These links distinguish general safety information from model-specific documentation. A manual directory helps you locate your unit’s instructions; it does not establish that every model uses the same parts, codes, or test values.
- Suburban: service and support (opens in a new tab)Identify the appliance behind the RV badge and obtain its operating instructions.
- PG&E: recognizing and responding to a gas leak (opens in a new tab)Emergency actions for suspected fuel-gas leaks.
Editorial standards and corrections · Prepare a useful service request