How we find the fault
We follow the Atwood ignition procedure, which starts with the wire connections and the ground. A loose connection or bad ground can kill the spark even when everything else looks fine. Once the electrical side checks out, we move to the spark electrode assembly. The gap has to be 1/8 inch, and the probes have to be clean and sitting in the gas-flow path. If the gap or probe position is off, the spark will not light the burner reliably.
Then we check propane pressure under load, with two or more gas appliances running. The Atwood manual calls for at least 11 inches water column. Pressure can read fine with nothing else drawing gas and then sag once other appliances are running. A heater that lights on its own but fails when the rest of the rig is running usually has a pressure problem, and a single-appliance check will not show it.
What we clean, adjust and replace
Most ignition failures come down to dirt, corrosion, or a probe that has shifted. We brush out the main burner tube to clear anything blocking the gas path, then clean and reposition the spark electrode assembly. Neither job needs a parts order.
If the electrode assembly is burned, pitted or worn out, we replace just that assembly, not the whole heater. We recommend a full tank water-heater swap only when the tank is corroded beyond repair, or when fixing an aging heater would cost about as much as a new one. In that case the new tank is an added cost on top of our labor.
What it costs
Labor for a basic RV tank water-heater swap typically runs $200 to $400. That covers the swap only, not the tank. We can give you that typical range on the phone, and we confirm the exact number once we see the unit.
A cleaning, an electrode adjustment or a loose ground wire costs less than a swap. A fault that takes longer to track down, or a second problem we find once the heater is open, costs more. If the diagnosis changes, we tell you what we found and why the number moved before any work is added to the bill.
From First Call to Finished Job
In practice, the work usually includes:
- On a Suburban unit, remove the anode with a 1-1/16-inch socket and replace it when consumption or weight loss exceeds 75%; apply potable-water-approved thread sealant to the replacement rod’s threads. [Suburban manual]
- If the tank is corroded, replace the water-heater unit; Mobile RV Pro states that tank corrosion is not repairable. [Mobile RV Pro]
What to Expect to Pay
Typical jobs fall somewhere in these ranges, and where yours falls depends on the details.
$30–$60
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