TCEA Furnace Repair

The TCEA furnace includes a silicon carbide (SiC) heating element that has been coated at the top end, on the areas of electrical contact, with a vapor deposited metal for better conductivity. It is part of an assembly consisting of two ceramic half-collars (one holding the thermocouple tube,) two ceramic spacers, two brass half-collars that provide electrical current, and the thermocouple. These parts are clamped together with two screws that seat in the threaded ceramic collars.

The more common type of failure is a cracked and broken SiC element. All of the other parts can easily be reused. The TCEA furnace heating element may be ordered from the original manufacturer for the lowest cost:

https://www.kanthal.com/en/ -a subsidiary of
https://www.home.sandvik/en/

Product code: GLOBAR SRO-1-29-150-300-25-2.55-1515-ZG4189
P/N: GB102824

Note that this is for the silicon carbide heating element only, and does not include the brass or ceramic collars, or the thermocouple. If in need of the complete assembly, try:

https://eaconsumables.com/  -or
https://serconlimited.com/

In our case, after hundreds of heating/cooling cycles, the contact between one of the brass collars and the SiC heating element failed, fusing one half of the collar to the heating element, and cracking one of the ceramic collars and both of the ceramic spacers. Perhaps caused by oxidation over time of the metal coating on the SiC element.

We were able to separate without further damage the brass collars from the element. These were resurfaced and polished at the area of contact. Replacement ceramic spacers were cut from surplus flat Al2O3 stock. The crack in one half of the ceramic collar did not pass between the screw holes so it could be reused.

Cost of repair:
SiC heating element, $397
Shop time, 2h @ $50/h, $100
Total, $497