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Ariston Clas 21 FF System Gas - Boiler Efficiency Ratings

Boiler Efficiency Rating

You can check your boilers rating by selecting it's make and model below. Ratings are based on the SEDBUK Rating which is an indicator of its efficiency when used within an average domestic household, it's a great benchmark for comparing new boilers and also assessing whether your current boiler would be better off being replaced due to low efficiencies.

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Ariston Clas 21 FF System Efficiency

SAP seasonal efficiency80.4%
Rating bandBand D


ManufacturerAriston Boilers
ModelClas 21 FF System
Fuel TypeGas
Flue TypeRoom-Sealed
FanFan Assisted
Output (kW)24.2 - 24.2
Boiler ID41-116-27
Manufactured From/To2007 - 2008


The Ariston Clas 21 FF System is a 'D' rated boiler with an efficiency of 80.4%.

The Clas 21 FF System is a Non-Condensing Conventional boiler with a maximum power output of 24.2kw that uses Gas as its fuel source.

Being a 'D' rated boiler it would be worthwhile replacing it with a higher efficiency 'A' rated boiler.

Similar Ariston Boilers to the Clas 21 FF System
(Non-Condensing Gas Conventional)

Results ordered by efficiency. Some models may be obsolete.

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