Will the Xtreme Heaters 250 Watt Enclosure Heater Keep an RV Water Pump from Freezing?

Updated 11/14/2026 | Published 02/17/2026

Question:

I've got a 2023 Grand Design Reflection fifth wheel, and I'm trying to keep the water pump from freezing when we get those cold nights. The pump sits in a small enclosed compartment that's about 3 feet long, 3 feet wide, and 3 feet tall. I'm looking at the Xtreme Heaters # XH99FR. Would this be a good size heater for that space, and will it turn on automatically when the temperature drops?

asked by: russell

Expert Reply:

Hey Russell! Yes, the Xtreme Heaters Industrial Enclosure Heater # XH99FR would be a great choice for adding some warmth around your water pump! Your compartment is about 27 cubic feet, and this 250 watt heater is designed for smaller, mostly enclosed spaces up to approximately 50 cubic feet. As long as the compartment is reasonably insulated, I think this will work well for your setup.

And yes, it takes care of turning itself on and off! The built in thermostat automatically kicks the heater on when the temperature drops to around 40 degrees and shuts it off once it reaches about 55 degrees. It also has a fan to circulate warm air around your pump and nearby plumbing, so you're not just heating one little spot.

You'll just need a properly grounded 110V outlet for the included 6 foot cord and a spot where the warm air can circulate freely. Keep in mind that it needs power to operate, and I'd still recommend winterizing when necessary rather than relying on the heater alone.

Do you keep your fifth wheel plugged into shore power throughout the winter?

expert reply by: Heather A