Boiler Types Flashcards

What is a biomass boiler?

Answer: A boiler that burns organic fuel such as wood pellets, logs or chips to provide heat

A biomass boiler burns organic materials (typically wood pellets, chips or logs) and is classified as a low-carbon renewable heat source, potentially eligible for incentive schemes.

What is the Boiler Plus standard introduced in England in 2018?

Answer: A requirement for new gas boiler installations to include additional efficiency measures such as weather compensation or load compensation

Boiler Plus (Part L, England 2018) requires all new gas combi boiler installations to include an additional efficiency measure: weather compensation, load compensation, flue gas heat recovery, or smart controls.

What is weather compensation in a boiler control system?

Answer: Adjusting the boiler flow temperature based on outdoor temperature to maximise condensing efficiency

Weather compensation uses an outdoor temperature sensor to continuously adjust the boiler flow temperature — lower when it is mild, higher when cold — keeping the boiler condensing efficiently and reducing energy use.

What is load compensation in a boiler control system?

Answer: Adjusting boiler output based on the difference between actual room temperature and the set temperature

Load compensation uses a room sensor to measure the difference between actual and desired temperatures and adjusts the boiler flow temperature accordingly, improving efficiency and comfort.

What type of flue system is used when a condensing boiler is installed in a compartment or room without ventilation?

Answer: Room-sealed concentric flue drawing combustion air from outside

When installed in a sealed compartment, the boiler must be room-sealed, drawing all combustion air directly from outdoors via the flue system, as no indoor air is available for combustion.

What is the purpose of a flue gas heat recovery unit (FGHRU) on a combi boiler?

Answer: To recover additional heat from flue gases to pre-heat incoming cold water, improving DHW efficiency

An FGHRU fits to the flue of a combi boiler and uses waste flue gas heat to pre-heat the incoming mains cold water before it enters the boiler, reducing the energy needed to heat DHW.