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Baxi 825 Heat Only Boiler

From £1,280.00

Baxi 825 Heat Only boiler comes with a 10-year warranty* and Adey Micro2 magnetic system filter in the box.

The Baxi 825 heat only boiler from Baxi’s 800 series. Compact and easy to install, this wall-mounted heat only boiler (also called regular, open vent or conventional) with its small dimensions is ideal for installation in a standard kitchen cupboard. With outputs from 16kW to 30kW, there’s a model to suit most properties and pockets. Versatile fluing for ease of installation.

  • No pump over-run or permanent live switch required
  • Quick and easy to install
  • Compact cupboard fit
  • Lightweight
  • Suitable for open vent and sealed system
SKU: N/A Categories: , , , Product ID: 1101


The Baxi 825 Heat Only Boiler, also known as a regular or heat, offers advanced heating solutions for modern homes. Its compact design and versatile installation options ensure seamless integration into any space. Equipped with cutting-edge technology, this boiler delivers exceptional performance and energy efficiency, providing reliable heating while minimizing energy consumption and reducing bills.

User-friendly controls simplify operation, catering to users of all technical abilities. Its intuitive interface allows for easy adjustment of temperature and settings, ensuring personalized comfort for every household member. Constructed from high-quality materials, the Baxi 825 Heat Only Boiler is built to last, offering durability and reliability for years to come.

Homeowners gain peace of mind from the consistent heating performance guaranteed year after year. Upgrade or install with confidence: the Baxi 825 Heat Only Boiler meets all heating system needs reliably. Its compact size and sleek design make it suitable for various household setups, while its advanced technology ensures efficient heating and reduced energy consumption.

Backed by Baxi’s reputation for quality and reliability, homeowners can trust in the performance of the Baxi 825 Heat Only Boiler. It is environmentally friendly, with features designed to minimize its environmental impact. Compatible with renewable energy sources, it allows homeowners to further reduce their carbon footprint.

This boiler excels in performance, efficiency, and reliability, making it the ideal heating solution for any home.. With its advanced technology, user-friendly controls, and durable construction, it provides unparalleled comfort and peace of mind to homeowners. Experience the benefits of this Baxi boiler in your home today.

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Additional information

Dimensions 37 × 27 × 62.5 cm

16kw, 25kw, 30kw

Flue Options

Baxi Multifit Horizontal Flue 60/100 (7222019), Baxi Multifit Vertical Flue 60/100 (5118576), Boiler Only – NO Flue


Baxi 800 Heat 16 Heat  25 Heat  30 Heat
Sales Code Boiler only 7749866 7749868 7749869
Controls and accessories
Operating mode selector switch with reset  Yes / no Yes Yes Yes
User adjustable CH temperature Range – e.g. 45° to 82° Yes Yes Yes
LED temp/status/fault diagnosis display Yes / no Yes Yes Yes
Baxi twin channel wired programmer 7212443 Optional Optional Optional
Baxi room thermostat 720971601 Optional Optional Optional
Boiler Plus ErP % 93.0 93.0 93.0
SAP 2009 annual efficiency (PCDB/SEDBUK) % 89.2 89.1 89.1
NOx class 6 6 6 6
ErP Product Information
NOx mg/kWh 20 24 24
Sound Power Level, Indoors LWA dB 39 45 49
Space Heating Efficiency Class A A A
Heat Input CH kW max gross (QnHs) 18.32 28.62 34.35
kW min gross (QnHs) 8.59 8.59 8.59
Heat Output CH (non condensing)  kW (Pn) 16 25 30
 kW (Pn) 7.5 7.5 7.5
Gas supply connection (mm) 22 22 22
Inlet supply pressure (natural gas) mbar 20 20 20
Maximum gas rate m3/hr 1.75 2.73 3.27
Mechanical and hydraulic 
Compartment ventilation required Yes / no No No No
Flow / return pipe size (mm) 22 22 22
Condensate discharge pipe size (mm) 21.5 21.5 21.5
Electrical supply Volts / Hz 230V/50Hz 230V/50Hz 230V/50Hz
Permanent live required Yes / no No No No
Switched live Yes / no Yes Yes Yes
Electrical power cable fitted as standard 1m of 3 core Yes Yes Yes
Power consumption Watts 20 33 44
External fuse rating Amps 3 3 3
Internal fuse rating 1.6T 1.6T 1.6T
Boiler IP rating (electrical protection) Approval category IPX4D IPX4D IPX4D
Pump overrun Yes / no No No No
Concentric flue system
Standard telescopic concentric flue Length in mm 315-500 315-500 315-500
Horizontal and Vertical concentric (60/100 mm) Max equivalent length (m) 6 6 6
Reduction per 135° bend (m) 0.5 0.5 0.5
Reduction per 93° bend (m) 1 1 1
Horizontal and Vertical concentric (80/125mm) Max equivalent length (m) 12 12 12
Installer lift weight (boiler) Max (kg) 17.4 17.4 19.5
Gross packaged boiler weight (kg) 21.3 21.3 21.3

Product Data

BAXI 800 Heat Only Energy Label UK

BAXI 800 Heat Only Installation Manual