BAP Combustion & Mechanical Systems Flashcards

In a forced-air heating system, what does a high temperature rise across the heat exchanger typically indicate?

Answer: Restricted airflow, often caused by a dirty filter or blocked ducts

A temperature rise above the manufacturer's specified range signals inadequate airflow, which stresses the heat exchanger and can lead to cracking and CO spillage.

What does 'draft pressure' measure in a vented combustion appliance assessment?

Answer: The negative pressure in the flue that draws combustion gases upward and out

Draft pressure is the negative pressure measured in the flue or vent connector that indicates how effectively combustion gases are being expelled from the appliance.

Which appliance type is MOST resistant to backdrafting caused by house depressurization?

Answer: Sealed-combustion condensing furnace

Sealed-combustion appliances draw combustion air directly from outside through a dedicated pipe, making them immune to backdrafting from indoor pressure changes.

A BAP analyst finds that a gas water heater's pilot flame is yellow and lazy. What does this most likely indicate?

Answer: Insufficient combustion air or a partially blocked burner orifice

A yellow, lazy pilot flame indicates incomplete combustion due to insufficient air supply or a partially clogged orifice, which can produce elevated CO.

What is the function of a barometric damper on an oil-fired boiler's flue?

Answer: To regulate draft and prevent excessive negative pressure in the flue

A barometric damper opens to admit room air into the flue, moderating excessive draft that could interfere with proper burner operation and efficiency.

Which measurement tool is essential for verifying gas supply pressure at a combustion appliance during a BAP assessment?

Answer: Manometer connected to the appliance test port

A manometer connected to the appliance's inlet pressure test port verifies that gas pressure falls within the manufacturer's specified operating range.