HVAC Furnace Sequence Of Operation

(Audio Only) Jason Obrzut comes on the podcast and talks us through his furnace sequence of operation training: “Take It Slow, It's Gonna Blow!”
There are 6 main steps in Jason's furnace sequence of operation training. The phrase, “Take It Slow, It's Gonna Blow!” should help you remember the sequence (Thermostat, Inducer motor, Safety switch, Igniter, Gas valve, Blower motor).
The first component in the furnace sequence of operation is the thermostat, which initiates the call for heat. So, the thermostat has to send the signal to the circuit board. After the board receives that signal, it sends 120v out of the board to the inducer motor.
Next, the inducer pulls the gas combustion air into the heat exchanger. That air will then be deposited into the exhaust. The inducer is what aids the venting action and is a critical part of a furnace.
The safety switch is a general term for a negative pressure switch with a hose connected to the inducer housing or heat exchangers. Negative pressure from the inducer motor will close that switch. When that switch closes, 24v goes back into the board.
Then, the board sends a signal to the igniter. Now, you will finally begin to see heat delays. Silicon carbide and silicon nitride are common igniter materials nowadays, but they are fragile.
Once the igniter has worked long enough, the gas valve opens. We get 24v from the board to the gas valve, which brings on the gas flow and starts a timer.
When the timer expires, the blower motor will come on. This component is the LAST one to come on.
Jason and Bryan also discuss:
Pressures on the flue
Cracked heat exchangers
Safeties not closing
Hot-surface vs. intermittent-spark vs. direct-spark ignition
Flame sensors and proving flame
DIP switches
Read all the tech tips, take the quizzes, and find our handy calculators at www.hvacrschool.com/

[@chickedwin7194]

Bryant you are doing a great job. From Dubai. Thanks

[@TheMuffinMan328]

Thanks for making these videos to refresh my knowledge.

[@HVACS]

Glad you like them!

[@brandonasherfield9860]

Great work I'm in 3rd semester for hvac/r. Thanks for motivating me to wanting to teach one day you have the most and best content 👌👏👐🙏

[@SombraLocs]

Great Podcast!

[@chuckdearruda6271]

Super podcast!

[@NemoTheGlover]

love this podcast bro

[@Jon-hx7pe]

around 26:00 -> the fan on delay isn't usually adjustable. it's locked at 30 to 45 seconds after ignition.

[@keithcorbin477]

What cause moist or water in pressure switch

[@dominiquepierre916]

Oh sorry what is the name of HVAC book ;
He said at the first of video but did not understand it clearly .

[@sushilkumar-kl4ok]

How to get this book?

[@srully1000]

link for the gas heat book?

[@rubenmagdaleno5247]

Me thinks this is the link. www.escogroup.org/training/gasfurnace.aspx

[@frankjames1955]

its probably good to show the furance as you teach IMo

[@Alex-yk6he]

Take it slow it’s gonna blow

[@moneybags7482]

Thermostat
Inducer motor
Safety switch
Ignitor
Gas valve
Blower motor