Is this an older unit with a spark pilot?
I understand, but the units had a sparking pilot and I was trying to differentiate between possibilities
Do you have a model number?
Does it do this all the time? Or just when running?
Normally I would say not a big deal...things tick and make noise....but the fact you hear it in and outside could be a relay dropping in and out. And if that is the case it could very well lead to damage. I apologize for not being able to be more specific, but given the description, I would have someone check it out.
Anytime a part short cycles, it is not good.