I recently purchased a house. The gas is turned off at this moment (not sure whether it's really turned off).
My water heater was not working (I figured out this when all the taps has no hot water). Then I went to basement and followed the instructions on the water heater to turn it on.
I put it on pilot mode and hold down the red button for a while then ignite 5-6 times. It didn't turn on. Then I thought it's not something I can fix. The moment I stepped away it gave big boom noise. I thought something is wrong and scared.

What might be the issue? Does it work anymore?

Sounds like a gas buildup. Check to see if pilot is lit. If not, try to relight.

Sounds like a gas buildup. Check to see if pilot is lit. If not, try to relight.

Thanks for your reply. I am kind of scared to touch it now. So I am trying to reach some plumbing experts who can help in this regards. I got couple of quotes, they are asking $75 - $150. Just to turn on water heater?? Seriously?

Turn gas to off.
No plumber is going to come out tonight anyway.
Find a friend that knows a little about lighting a water heater.
It not difficult but we don't know what you did wrong but you got a build of gas and then it ignited. You certainly don't want to start a fire.

The plumber has to charge that much He has to spend the time going to your house and then back to the shop. He has to pay for the gas, the truck and the employee wages, insurance and the taxes.

Ask a neighbor, good way to get to know them.