Here’s how we calculated this possible saving:
• The average UK household spends £646 per year on their gas bills based on 15,000 kWh consumption.
• The average semi-detached house in the UK saves £205 on their heating bills when they replace a ErP G rated boiler with an A rated one.
• Switching to a new Vaillant ecoTEC boiler operating at a maximum of 94% efficiency could reduce your energy use by 30%.
• This is calculated as average saving (£205) ÷ average yearly spend (£646) = 30% reduction.
 Table 235 (48 kB) This can also be downloaded from: https://www.gov.uk/government/statistical-data-sets/annual-domestic-energy-price-statistics