I’m troubleshooting a carter hoffmann fh90-0015b, the heating element is working intermittently. It works out of the warmer, suspect that high limit switch. Advice please?

[ectofix]

You want advise?  My advise is to call a cooking equipment service company.

 

Although that heating unit is relatively simple inside, there’s greater possibilities for failure if it’s repaired improperly.  A HVAC tech or a licensed electrician probably wouldn’t repair it correctly.

High-temp wire terminals; hi-temp wires; specific electrical testing necessary to identify potential component failure; etc.

[fixbear]

Works out of the cabinet but not in?  Check your power cord and plug were it goes though the cabinet.  Or your wall outlet.  Not uncommon for a loose plug or connection. 

 

Sometimes the vertical duct drops a bit and prevents the heater from going all the way back.

 

BTW, your number is just the heater.  So what cabinet do you have?  Is the blower fan working correctly?  The only reason for a high limit trip is lack of air flow.