Gary McCreadie is an HVAC tech, the creator of hvacknowitall.com and the HVAC Know It All Podcast   The Hot Gas Bypass Valve Explained Hot gas bypass valves are a simple and very effective way to add a false load on an evaporator coil.  What is a false load, you ask.  Well, as…

Carbon Monoxide Testing and CO Action Limits! By:  Eric Shidell, HVAC Service Mentor Carbon Monoxide is an odorless, colorless poisonous gas that is a natural and common product of combustion of all kinds.  Most gas burning furnaces normally produce carbon monoxide as a part of their operation.  When all systems are operating…

Flame Rectification Explained                                                                          By Gary McCreadie A jittery pilot flame sits in a damp, poorly lit room.…

A Life Well Lived  By Steve Driver                                                                                         …

A Christmas On Call                                                                                             …

Tip: Protecting Tools and Electrical Components  By Gary McCreadie A few years ago I was running into economizer control board issues.  The boards were corroding as a result of sitting in the outdoor air stream.  I was changing them yearly in some cases.  Yes, if you are able to install the control…

Tip: Five Minutes To Be A Better Tech By Gary McCreadie This tip is brought to you by my advanced refrigeration instructor.  He repeated weekly, "the difference between a good technician and a bad one is five minutes."  How is that possible?  The intended message was to differentiate between the tech that spends an…

Tips For The New On Call Tech By Brian Flesch I will start off with a bit of my background, I have been a service technician in the commercial and industrial side of things for about 11 years now and somethings have just stuck with me that I picked up from senior technicians.…

It’s Sunday night, the snow is falling gently at a steady pace in my small town just north of Toronto.  Something in the air has triggered my mind to re-conjure up images of HVAC and trade related tattoos, actually that’s complete bullshit, I purposely sat down to write this article.  It really is snowing though….

A few months back in My HVAC Hub powered by HVAC Know It All, my private discussion group on Facebook, I asked a question for fun.  “If you won the lottery, would you continue to work in the industry?”  Perhaps not the exact wording, but something pretty close.  I received…

Most of us have heard the statement, Work Smarter, Not Harder before. So, what does that mean in a residential HVAC service business?  1)    Take the shortest route to the call? 2)    Make sure your truck is stocked with the right parts before you head out for the day 3)    Pack your lunch…

Rick Ruscigno CMHE Lincoln Technical Institute mr.rickruscigno@gmail.com The Hot & Cold Of It Vol 1 First Impressions We are all familiar with the saying, “don’t judge a book by its cover,” but the truth is you will in fact be judged within your first seven seconds of an encounter. A first impression is formulated by at…

Tip: Raise Refrigerant Tank Pressure For Easier Charging In Cold Weather  By Gary McCreadie If you work in an area of the world where winters are harsh, then you have probably experienced difficulty charging a system due to low refrigerant tank pressure.  Refrigerant tank pressure is directly related to the ambient temperature…

Pulling a proper vacuum is vital to the operation and longevity of any refrigeration or cooling system.  Moisture and other contaminants that are not removed can wreak havoc on system internals over time and can cause premature failures.  Lets go through the steps of pulling a proper vacuum.   1.    Start…

I am very excited to post this blog, Steve is the first official guest blogger at hvacknowitall.com.  Apprentices pay attention, thanks Steve!  If you are interested in contributing in any way shoot me an email gary@hvacknowitall.com.  Happy HVACing!   The Do's & Don’ts of an HVAC apprentice By Steve Wiggins The night before his first…

Tip: Carry Your Own CO Detector By Gary McCreadie Safety, as always should be at the forefront of each and every job.  It is very easy to become complacent and take safety measures for granted.  CO (carbon monoxide) is produced during the incomplete combustion of carbon.  In small amounts, it can cause…

As I sat and pondered the use of profanity that is used daily in the trades, I was also coincidentally listening to the Howard Stern show.  My new Ford Transit 150 comes with a free trial of Sirius Satellite Radio.  I used to listen to Howard fifteen years ago when…

Back in fifteenth century Japan, the Ninja were known as mercenaries or spies responsible for sabotage, assassination, espionage and many other devious actions.  Being the complete opposite of the honourable Samurai, who would battle face to face with their opponent, the Ninja would carry out their mission in the shadows…

Tip: Seal Your Service Valve Caps For A Leak Free System By Gary McCreadie It wasn't too long ago I performed a leak check on a couple of large chillers.  I used my Testo 316-3 electronic leak detector for the inspection.  I found no significant leaks, but what I did find was…

  What is an economizer?  Simply put, it is a mechanical device that is designed to reduce the consumption of energy, whether it be fuel, electricity, or other. According to Wikipedia, the first economizer was patented by Edward Green in 1845.  It was used to increase the efficiency of stationary steam…