12V DC Water Heater Thermostat Switch (525007) by Suburban. If you’re not a winter swimmer and don’t want to shiver under the cold shower, do the dishes, wash clothes, or anything in between, then install this top-notch RV product to make your experience more comfortable and relaxing in any season. With it, you’ll instantly get hot water for all your recreational needs. Manufactured with quality and precision in mind, this product will provide many years of reliable, trouble-free service.