Propane and carbon-monoxide hazard: If you smell gas, evacuate, shut off the propane at its source, avoid switches and flames, and contact the gas supplier or qualified RV technician. Soot requires immediate shutdown.

Suburban's IW60 and recirculating IW60RL are demand water heaters. They do not keep a tank hot; they watch for water flow, begin an ignition sequence and heat only while hot water is being used. That makes water demand the first check, not the last.

Open one hot faucet fully

The official IW60 guide specifies at least 0.5 gallon per minute for operation. Open a hot faucet fully and watch the controller or reset light. If the heater lights at a sink but not at the shower, clean the shower head and screen and check its shutoff button. Suburban advises against using the shower-head pause button because stopping or reducing flow can shut the heater down.

Flow restrictors may also reduce performance. Verify the fresh tank is full or the city-water valve is open, and make sure winterizing or bypass valves are in the normal-use position.

Purge air from the water lines

After dewinterizing or running the fresh tank empty, open hot and cold faucets until flow is steady. Air through the heater can interrupt demand sensing and cause temperature swings. On an IW60RL with a loud recirculation pump, Suburban says air is a common cause and recommends running hot water at multiple faucets to flush it.

Confirm 12-volt power and propane

Turn on electrical power to the appliance and the main propane supply. Check the water-heater fuse and house-battery voltage. The control and ignition sequence need stable 12 volts even though the burner uses propane.

Light a stove burner only if there is no gas odor and the appliance instructions permit it. A weak or unstable flame suggests a broader propane supply or regulator problem. Do not adjust gas pressure without test equipment.

Understand the three ignition trials

Suburban states that if the first trial for ignition fails, the IW60 makes two more attempts. After the third failure it enters lockout. The red RESET light may remain on at the switch plate.

To reset from lockout, turn the control off, wait five seconds and turn it back on, or cycle the water demand as the matched control instructions describe. On first startup, more than one normal ignition cycle may be needed to purge air from the propane line.

Do not turn resetting into the diagnosis

If the heater repeatedly locks out, note whether you hear the blower, clicking ignition and burner flame. No blower, spark with no flame and flame that lights then drops out are different faults. Stop after a reasonable controlled test and let a technician inspect gas pressure, ignition and flame sensing.

Check the exterior vent

With the heater off and cool, inspect the vent cap for insects, nests, mud or stored objects. Suburban calls for periodic soot inspection and says soot indicates incomplete combustion that must be corrected before operation.

Do not insert tools into the burner or alter the vent. Combustion and gas-valve service belong to a qualified technician.

If water starts hot and then goes cold

Watch water flow. Mixing in too much cold water or pressing a shower pause button can drop hot-side flow below the operating threshold. Set a comfortable outlet temperature and keep a steady hot-water demand rather than repeatedly closing the hot side.

On IW60RL models, remember that recirculation may cycle periodically by design. Continuous operation can also stop after the system's three-hour energy-mode limit.

When to call for service

Arrange qualified service for repeated ignition lockout, soot, gas odor, unstable flame, water or gas leaks, a dead blower with verified power, or a burner that lights and immediately loses flame. Suburban specifies qualified service for repairs and maintenance beyond normal owner operation.

Related RV Solver pages

Frequently asked questions

Why won't my Suburban IW60 ignite?

Check for at least 0.5 GPM hot-water flow, steady 12-volt power, propane supply, purged water and gas lines, and ignition lockout.

How do I reset a Suburban IW60 after ignition lockout?

Turn the control off, wait five seconds and turn it back on, following the matched switch or On-Demand Control Center instructions.

Why does my IW60 work at the sink but not the shower?

The shower head, screen, flow restrictor or pause button may reduce hot-water flow below the heater operating threshold.

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Sources and review notes

Reviewed against manufacturer material on July 12, 2026. Match every fault definition, procedure, limit and replacement part to the exact model, specification and serial range installed in the RV.