The title pretty much says it... the circuit board is United Tech Electronic Controls HK42FZ010 and it's giving LED code 4 short, 3 long. I see from another post that this is "Low-heat pressure, draft safeguard, or auxiliary limit switch open while high-heat pressure switch closed", but I have no idea what to do next. Help, anyone?

More information... I can see both of the vacuum valves opening & shutting when I turn it on & the draft motor begins running. We had some high winds recently and I'm wondering if that could have tripped the draft safeguard, but I don't know where that is.

Still more information... bypassed limit switch per posting here: https://www.askmehelpdesk.com/heating-air-conditioning/bryant-plus-80-no-heat-293962.html

Still no luck.

What's the model number on the furnace?

Thanks for your willingness to help. It is Bryant 330AAV060135.

Can't find much on that furnace. Can you post a pic of the wiring diagram? Yes high wind's can cause a problem.

Took me a while to find it, but I believe I did, here: http://dms.hvacpartners.com/docs/1009/Public/04/SP04-48.pdf

Thanks again, I really appreciate it.