My trane xl90 furnace tries to ignite but won't. What should I do to fix it?

Answer:
Something is wrong, look for a reset button and press it once, closed gas valve etc. If that doesn't fix the problem and you don't have the expertise to troubleshoot and determine the cause of the problem, call for service.
Note: There are comments associated with this question. See the discussion page to add to the conversation.
First answer by H2045. Last edit by Theprismgroup. Contributor trust: 752 [recommend contributor recommended]. Question popularity: 1 [recommend question].