Gas Heat and Combustion — From Ignition to Exhaust
- Ignition sequences explained: what fires when, and what proves it
- Flame sensing, heat exchangers, venting and combustion analysis
- Carbon monoxide safety, with the reasons behind the limits
- 80-page paperback
Email infohvacresource@gmail.com and a real person will answer within one business day.
How it works
Delivery takes 5 to 15 business days to the United States, Canada, the United Kingdom, Australia and New Zealand. Shipping is calculated at checkout, and you get a tracking number by email as soon as your parcel moves.
What's inside
Everything a service technician needs to know about gas-fired heating equipment. Covers natural gas and LP properties, ignition sequences (standing pilot, intermittent pilot, hot surface, direct spark), flame sensing, heat exchangers, venting categories, combustion analysis and CO safety — each topic explained with the why, not just the how.
- Gas properties, manifold pressure and orifice sizing
- Ignition sequences: what fires when and what proves it
- Flame sensing: microamps, flame rectification, troubleshooting
- Heat exchangers: visual inspection, combustion analysis, when to condemn
- Venting: categories I–IV, common vent tables, condensing furnaces
- CO safety: testing, thresholds and the 400+ annual deaths the CDC reports
Written for the technician standing in front of the furnace.
Shipping and returns
If something is not right, request a return within 3 days of receiving your order. Items must be unused and in their original packaging. Approved refunds go back to your original payment method within 10 business days.
If your parcel arrives damaged or never arrives, email us within 7 days of the delivery date and we will sort it out.
Full details: Shipping Policy and Refund Policy.
Why knowing the reason matters
Americans die each year from unintentional carbon monoxide poisoning not linked to fires.
Source: CDCHow much less energy an air conditioner can use when its filter is routinely replaced or cleaned.
Source: U.S. Department of EnergyFor refrigerant in new US home AC and heat pump systems made or imported since January 1, 2025.
Source: U.S. EPA
A tradesman who knows why a reading matters finds the fault faster, gets fewer callbacks and can work out the system that is not in the manual. Rules you only memorize fade. Reasons you understand stay with you on every call.
From the author, Charles Smith“Service manuals tell you what to do. Our books tell you why.”
A wrong charge, a missed airflow problem or a skipped vacuum step can mean a callback, a burnt-out compressor or an unsafe furnace. HVAC Resource titles turn the numbers you meet on every call into something you can reason through: plain language, the reason behind each reading, diagrams and step-by-step examples.
Under EPA rules, technicians who maintain, service, repair or dispose of equipment that could release refrigerants must be Section 608 certified.
Source: U.S. EPAEverything a service technician needs to know about gas-fired heating equipment. Covers natural gas and LP properties, ignition sequences (standing pilot, intermittent pilot, hot surface, direct spark), flame sensing, heat exchangers, venting categories, combustion analysis and CO safety — each topic explained with the why, not just the how.
Get Gas Heat and CombustionFour things that make HVAC make sense
Each rule and reading comes with the reason behind it, so it sticks.
Systems drawn the way they look in the field, one component at a time.
Superheat, subcooling and airflow worked through line by line.
Written for apprentices and working techs, at the bench or on the truck.
A look inside Gas Heat and Combustion
Studying for EPA 608? Learn the reasoning, not just the rule.
Certification exams check whether you understand the rules, not whether you can recite them. HVAC Resource titles explain why each rule exists and how it applies on a real call.
One reference to get the whole crew on the same page.
When apprentices, service techs and installers learn from the same explanations, everyone reads a system the same way. Keep a copy on the truck and one in the shop, so the reason behind a reading is never more than a page away.
Training a group? Choose Buy 2 or Buy 3 above, or email infohvacresource@gmail.com for a larger order.
Order for your teamFrequently asked questions
Who is this for?
Apprentices, students and working HVAC/R technicians who want to understand the reason behind the readings they take, not just memorize the numbers.
How long does delivery take?
Delivery takes 5 to 15 business days to the United States, Canada, the United Kingdom, Australia and New Zealand. Shipping is calculated at checkout, and you get a tracking number by email.
How do eBooks and digital downloads work?
Digital products are delivered right after checkout as a download you can open on any phone, tablet or computer. Because they are delivered instantly, digital sales are final.
What is your return policy?
You can request a return within 3 days of receiving your order. Items must be unused and in their original packaging. Approved refunds go back to your original payment method within 10 business days. See the full Refund Policy.
Do you have Spanish editions?
Yes. The Fundamentals Handbook comes in Spanish as a paperback, an eBook and a workbook, and the Inverter Mini Split guide comes in Spanish as a paperback. See the full catalog.
Can I order for my crew or class?
Yes. Choose Buy 2 or Buy 3 at the top of the page, or email infohvacresource@gmail.com for a larger order.
Does this replace local code or manufacturer instructions?
No. Our materials are for education and exam preparation. Always follow the codes that apply where you work and the manufacturer's instructions for the equipment you service.
Who do I contact with a question?
Email infohvacresource@gmail.com and a real person will answer within one business day.