RV Propane and Water Heater Problems on the Road

Propane appliances in an RV are simple systems that fail in predictable ways, and they are also the systems where doing the wrong thing has real consequences. Work through them in order and know where the line is.

The safety rule comes first and it is not negotiable: if you smell propane, shut the tank valve, get everyone out, ventilate, and do not operate anything electrical until it clears. A propane leak in an enclosed space is not a troubleshooting exercise.

Start at the supply

Is there propane in the tank. Is the tank valve open. Has the regulator been switched to an empty bottle on a two-bottle setup.

More appliance calls than anybody wants to admit come down to an empty bottle or a valve that was closed and forgotten.

The regulator

The regulator drops tank pressure to what the appliances need. When it fails, appliances run poorly, burn with a yellow lazy flame instead of blue, or will not light at all.

Regulators have a service life and they are exposed to weather. A regulator that has been on a trailer for many years is a reasonable suspect.

Water heaters specifically

Most RV water heaters run on propane, electric, or both. The first useful question is whether it fails on both modes or only one. Failing on propane only points at the gas side. Failing on electric only points at the element or its supply. Failing on both points at controls or the thermostat.

• A pilot or igniter that will not light, which is often a dirty burner assembly or spider webs in the tube
• An igniter that sparks but does not light, pointing at gas supply or the gas valve
• It lights and goes out, which is frequently the thermocouple or flame sensor
• No hot water on electric, which is usually the element or the thermostat
• Water heating but not getting hot, which can be a thermostat or a tank full of sediment

Spider webs in the burner tube are a genuinely common cause and they are seasonal. An RV that sat all summer frequently has one.

The anode rod

Water heaters with a steel tank use a sacrificial anode rod that corrodes so the tank does not. It is a consumable, and an RV that has never had one replaced probably needs it.

A rod that is mostly gone means the tank is next, and a tank is not a repair.

Sediment

Minerals settle in the bottom of the tank and insulate the heat source from the water. The result is longer heat-up times, less hot water and a heater working harder than it should.

Draining and flushing the tank periodically is basic maintenance and it gets skipped on rigs that only come out a few times a year.

Do not work on the gas side of an appliance if you are not comfortable with it. Propane is forgiving right up until it is not, and the failure mode is not a broken part.

Furnaces have the same pattern

An RV furnace that will not light follows the same logic — supply, regulator, igniter, gas valve, sensor. Add a blower that has to prove airflow before the gas valve opens, so a furnace that runs the fan and never lights is often the sail switch or a blocked exhaust.

Blocked exhaust is worth taking seriously. Mud daubers build in furnace and water heater exhausts on rigs that sit.

The seasonal problem

Most RV propane failures show up on the first trip after the rig has been sitting. Webs in burner tubes, mud dauber nests in exhausts, regulators that seized, and batteries that went flat and took the control boards with them.

A shakedown check before the first real trip catches nearly all of it in a driveway rather than at a campsite.

Electric elements

On a heater that does both gas and electric, the electric element is a common and cheap failure. Symptoms are hot water on propane and none on electric.

Elements also fail from being run dry. Switching the electric side on with an empty tank burns the element out quickly, which is why the sequence at every startup is fill the tank first, then turn things on.

The bypass valve

Most RV water heaters have a bypass for winterizing. Somebody who winterized the rig and never switched it back gets no hot water and a heater that seems to work fine.

It is the first thing to check on the first trip of the season, and it accounts for a fair number of no-hot-water calls that turn out to be a valve position.

Same category as the empty propane bottle — not a failure, just a setting nobody reset.

If you are sitting somewhere with no hot water or a furnace that will not light, call (850) 495-0366. Dispatch answers 24 hours and James comes to the rig wherever it is parked in the panhandle.