Fan running at fuse box

[mtiebout]

I have a 2019 Compass 23TB. I am camping now and the fan keeps running behind the fuse box. I have not noticed this before! What is it and how can I stop it?
Also does anyone else have trouble with hot water? We have a tankless water heater and it does not supply much hot water.
Thanks,
Mary

[widdershins]

Are you connected to shore power? If so, it's likely the fan for your power converter, you do not want to stop it as that'll likely lead to premature failure due to heat.

Some tankless heaters are only rated to heat x degrees over incoming water temperature. What specific brand/model of heater?

[mtiebout]

Yes we are connected to shore power. Why have I not heard this noise before?
And thank you for the heads up about the water heater-I will look that up!

[Judge]

Depending on the Converter, it can have a variable speed fan. If the Converter starts getting hotter, the fan can start spinng faster for cooling so it is more audible.

The Converter can get hot from charging deeply discharged batteries or because of warm ambient temperatures.

[robertj1961]

Not sure if you have a converter or an inverter, but either one probably has a fan. The fan on my inverter seems to run most of the time if temperatures are elevated at all. Even in low 80 degree range it will run. That is most likely what you are hearing and nothing to be concerned about. If an inverter, can run rather plugged in or not.