2.4GPM Thankless Gas Water Heater Model FWHO9AFA

[sim444]

Bought a camper trailer Grand Design imagine 15RB 2024 last February 2024 pick it up May 2024 from dealership had no problem with 2.4GPM Thankless Gas Water Heater Model FWHO9AFA .Set the wall controller temperature to 102 Fahrenheit never had any problem .But when we arrived in Texas in October 2024 the hot water no control set at 102 but go up always try fix it with the troubleshooting but did not work. Try everything to fix it plumber told me have to do a decalcification the unit is new bought the camper February 2024 pick it up May 16 2024 may fit it what should I do even when the thermostat is settle at 95 f when running the water goes up to 113 to 130 .

 

[grawlsnc]

Likely your water supply pressure was too low at the campground in Texas.
I had the overtemp issue at a CG when they told me at check-in that the water pressure was low (40-45 psi).
Haven't had the problem before or since.

 

[ddepew]

Bought a camper trailer Grand Design imagine 15RB 2024 last February 2024 pick it up May 2024 from dealership had no problem with 2.4GPM Thankless Gas Water Heater Model FWHO9AFA .Set the wall controller temperature to 102 Fahrenheit never had any problem .But when we arrived in Texas in October 2024 the hot water no control set at 102 but go up always try fix it with the troubleshooting but did not work. Try everything to fix it plumber told me have to do a decalcification the unit is new bought the camper February 2024 pick it up May 16 2024 may fit it what should I do even when the thermostat is settle at 95 f when running the water goes up to 113 to 130 .

When the incoming water is warm like in FL or TX you can go outside and there is a flow control. Turn it up as more flow is less time over the flame. Honestly if the incoming is too warm shower cold or go to the shower house.

 

[Jomani]

Definitely sounds like a water flow issue. Below is a link to a quick little video I put together to demonstrate the issue. Try putting some water in your fresh water tank and run from the water pump to verify. Things like water filters, pressure regulators and filter screens can cause this issue. If this unit were a couple years old, I could understand recommending a descale, but not a new unit.