How to Change the Heating Element and Gasket for an InSinkErator InstaHot
The InSinkErator Instant Hot Water dispenser (often called the InstaHot) is a staple for many kitchens, providing near-boiling water on demand. However, over several years of use, mineral scale buildup can cause the heating element to burn out or the gaskets to degrade, leading to leaks. While InSinkErator often recommends replacing the entire tank unit (SST-FLTR or HWT-F1000S), advanced DIYers can sometimes service the unit to extend its life.
Signs Your Heating Element or Gasket is Failing
- Water is Lukewarm: A clear sign the heating element is no longer reaching the required 200°F.
- Tripped Circuit Breaker: A shorted element will often trip the GFCI or the main breaker immediately upon being plugged in.
- Leaking from the Bottom: This usually indicates a failure in the main tank gasket or the seals around the heating element terminals.
- Hissing Sounds: Excessive scale on the element can cause loud "kettle" noises as it struggles to heat.
Safety First: Pre-Repair Checklist
Warning: You are dealing with water and high-voltage electricity. Always perform the following before starting:
- Unplug the unit from the electrical outlet.
- Turn off the water supply valve leading to the tank.
- Open the faucet handle to drain any remaining hot water and relieve pressure.
- Wait at least 30 minutes for the internal tank water to cool down to avoid scalding.
Step-by-Step Replacement Instructions
1. Remove the Tank
Disconnect the plastic and copper lines from the top of the tank. Note the positions of the clear, blue, and red tubes. Lift the tank off its mounting bracket and bring it to a workbench or sink. Drain the remaining water by turning the tank upside down.
2. Open the Tank Housing
Most InstaHot models have a metal or plastic outer shell. Remove the screws at the base or top to slide the housing off. This will expose the stainless steel tank and the electrical components.
3. Accessing the Heating Element
The heating element is typically bolted into the side or bottom of the tank with a large nut or a series of smaller bolts.
- Disconnect the electrical leads (spade connectors) from the element terminals.
- Use a socket wrench to unscrew the element.
- Carefully pull the element out. It may be covered in white calcium deposits, making it difficult to slide out of the hole.
4. Replacing the Gasket and Element
InSinkErator tanks use a high-temperature silicone gasket to seal the element.
- Clean the Surface: Use a Scotch-Brite pad to clean the tank opening. Any leftover scale will prevent a new gasket from sealing.
- Install the New Gasket: Seat the new gasket firmly around the new heating element base.
- Insert and Tighten: Thread the element into the tank. Tighten firmly but avoid over-torquing, which can deform the silicone gasket and cause leaks.
5. Reassembly and Testing
Slide the housing back on and reconnect the water lines. Crucial Step: Turn on the water supply and open the faucet until water flows steadily before plugging the unit back into the wall. Plugging in a dry tank will instantly burn out the new heating element.
A Note on Parts Availability
InSinkErator officially considers these units non-serviceable for liability reasons, meaning they do not sell individual elements or gaskets directly. However, third-party "rebuild kits" are available online, and the gaskets are often standard 1-inch or 1.25-inch high-temp silicone O-rings. If the internal stainless steel tank is pitted or rusted, a gasket replacement will not fix the leak; in this case, a new tank is required.
Conclusion
Replacing an InSinkErator heating element and gasket can save you the $200+ cost of a new tank. By carefully removing mineral scale and ensuring a clean seat for the new gasket, you can restore your instant hot water system to peak efficiency. If the project feels too complex, remember that modern InSinkErator tanks are designed for "Easy-Swap," allowing you to replace the entire canister in minutes using the existing plumbing lines.
