The Toyotomi 20476406 is a genuine High Limit Switch for BS-36UFF, OM-148, OM-122DW. Safety switch that shuts the burner down if the heat exchanger overheats. Replace when the heater trips on high limit with normal water flow.
This is an OEM Toyotomi part, so it fits and performs the way the original did. Confirm your heater model before ordering; the model is on the rating label on the unit. If you are not sure which part you need, Rural Energy support can check it against your model and serial number.
Rural Energy is a Toyotomi distributor and keeps Oil Miser water heater parts in stock for fast shipping to dealers and homeowners.