My house furnace pilot light not working although repeated several times restart procedures.
Not sure what caused this problem.

Can you describe what you are doing and what happens when you do it??

The brand is Bryant , model 376B. I did the procedures as instructions, set thermostat to lowest temperature, turn control dial on gas valve on, turn on electrical supply, open external manual gas valve, set thermostat slightly above room temperature.

Look at the circuit board for an LED light flashing a code. Model 376B doesn't seem like the right, or complete model number. Do you know how old and efficiency?

Model number is copied from operation manual. The furnace is over 10 years. How to check a thermostat working or not? Are thermostat and thermocouple the samething?

The thermostat is what tells the gas valve to come on and heat the house. The thermocouple is a safety device that goes from the gas valve to the pilot light, if the thermocouple is not hot the gas valve with not open and let the gas flow through. Also if the thermocouple is bad The pilot will light but when you release the button, that you are suppose to hold down for thirty seconds, the pilot will go out. Does it have a pilot that you have to light or does it have an automatic pilot.

10 year old Bryant? Probably doesn't have a standing pilot or thermocouple. Sorry I need more information.

As shown on a instruction which came with the furnace inside the furnace that the pilot light will turn on automatically when it calls heat then the flame will come on. Both pilot light and flame will distinguish when reachs set temperature.

I just bought a new thermostat to make sure it works first. The gas dial control can only turn to off or on needs not to press to hold or when turn the knob.

I have checked the parts list but couldn't find thermocouple on the list.

If I can not fix it. How much will an average service charge if I call a technician?

Have you verified the furnace is getting control voltage? Does it have any lights to light? If nothing at all is happening, the control voltage fuse could be blown or even the breaker tripped. Start with finding the breaker and turning it all the way to off and then all the way back to on. Then open up the furnace and look for an automotive style blade fuse on the control board. Both easy fixes.

Sorry I didn't suggest this before, but a sure check of the thermostat is to connect a wire from the R to the W terminal on the furnace control board. If the furnace doesn't start up when the cover switch is closed, the problem is in the furnace not the thermostat.

Those are the basic resest steps, OR it could be simple as the manual reset -- I've paid a couple times for a tech to reach in and press a reset button that senses backdraft -- which can happen in windy conditions -- I hope I'll remember