My Fogatti InstaShower 8 Plus RV Tankless Water Heater Won't Fire Up, Need Troubleshooting  

Question:

Expert Reply:

Hello Kevin,

I thought it was fixed, I am very sorry to hear that you are still having issues.

Since your Fogatti 8 Plus like # FG86FR will not fire and the induced draft motor is not coming on, the heater is stopping very early in the ignition sequence. This typically indicates a power, control, or safety interlock issue rather than a propane supply problem. The induced draft motor and control board both operate on 12-volt DC power, so the first thing to verify is that your RV battery voltage is at least 12.0 volts, ideally closer to 12.4–12.8 volts. Make sure the house battery disconnect is turned on, the water heater fuse (typically 10 or 15 amps) is not blown, and there is no failed inline fuse near the unit. Low or unstable voltage is one of the most common reasons the control board will not attempt to start the fan.

Next, cycle the water heater off and back on using the on/off switch or wall control panel, waiting about 30 seconds between cycles. Confirm that the display or control panel powers up normally and does not appear dim or flicker, which can also indicate a low-voltage condition. A loose or faulty control cable between the control panel and the heater can prevent the unit from initiating the startup sequence.

With power disconnected, remove the exterior access cover and visually inspect the wiring connections at the heater. Look for loose connectors, damaged or pinched wiring, or signs of corrosion, particularly at the ground connection. A poor ground can prevent the induced draft motor from receiving power. Reseating connections is often sufficient to resolve an intermittent or connection-related issue.

If power and wiring appear to be in good condition, the next area to consider is the heater’s safety circuits. If any safety switch or sensor is open, the control board will not allow the unit to proceed with startup or energize the induced draft motor. This includes components such as the high-limit switch, exhaust temperature sensor, and freeze protection sensor. Ensuring these connections are secure and undamaged is an important part of the diagnostic process.

When proper voltage is present, wiring and grounding are intact, and no safety devices are interrupting the circuit, the remaining likely cause is a control board issue. Control boards can be sensitive to low voltage, power interruptions, or grounding problems, all of which can prevent the startup sequence from beginning. In many cases, resolving a power or ground issue restores normal operation without further repair.

I’ve included a link to the instruction manual for reference, and the Fogatti 8 Plus troubleshooting and error code section begins on page 19 (side page number 22), which can help identify any fault conditions indicated by the unit.

Let me know if you need more information Kevin!

expert reply by: Kate F

0

Troubleshooting
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Troubleshooting
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Kate F.

1/27/2026

Hey Kevin, how did things go after checking the voltage and wiring on your Fogatti 8 Plus water heater? Did reseating the connections or cycling the power get the induced draft motor running again? Your update could make it easier for the next person with the same issue.