Thermostats for gas water heaters are available for shoppers to buy online from Sears PartsDirect, ApplianceZone and SupplyHouse.com, as of 2015. These online retailers carry a variety of thermostat assemblies for natural gas and propane systems.
Sears PartsDirect offers guaranteed shipping on the same day as the purchase for many in-stock items, including thermostats, and the company's website also claims that parts are manufacturer-approved for a guaranteed fit. ApplianceZone offers a hassle-free 90-day return policy and provides free shipping for orders totaling $150 or more. SupplyHouse.com shoppers benefit from user reviews and question-and-answer sections on product pages that address many customer concerns about thermostat assemblies for gas water heaters.