Are you talking about your 4/4/2 C&O cab#8142?
If so that's a sealed smoke unit and does not have a wick. I've found most issues I have with this smoke unit are that it is not grounded correctly.
First check the connection underneath at the front pilot truck, even if it looks secure loosen it and make sure it's a clean connection.
If that doesn't correct the situation you'll have to remove the shell and check the wire connections first on the ground side on the way to the pilot truck. than on the power side. The headlight and the power side of the smoke unit share the same connection and are wired together during manufacturing. If you've been having trouble with the headlight too, and the shared connection looks good I believe you can trace the power back to the e unit and check that connection.
If the element is burnt out you can replace the smoke unit, though the replacements do not have the contacts for the Mighty Sound of Steam sound effects. I have had success adding my own contacts for the sound effects to the replacement smoke units and they smoke better than the originals. The replacements also have an LED hard wired to them I think that may be to knock down the voltage to the heat element. I usually remove the LED.
The picture above is from the Train Tenders website. He should have them in stock http://ttender.com He should also have the traction tires and any other parts you may need for the engine.
Patrick you have e-mail PDF file; Diagram for the C&O cab #8142, 4/4/2
