Heat Only Boilers

Baxi 800 Heat

The Baxi 800 Heat includes a compact Adey MagnaClean Micro2 system filter to protect the boiler and heating system.

This boiler can be installed on open vent or sealed systems and has an optional in-case rear flue for a neater installation.

Double points return for Baxi installers – Now even bigger and better!

We’re giving you double points on qualifying products from 2nd October 2026 – 31st January 2027. Work done. Points doubled. Simple.

All you need to do is install and register qualifying products on our loyalty scheme Baxi Works* and those double points are yours!
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Features and Benefits
Product Literature
Dimensions
Technical Specification

Features and Benefits

Multiple outputs

Available in outputs of 16, 25 and 30kW

Flexible

Top central or optional in-case rear flue giving flexibility to site

Lightweight

Only 17.4kg installer lift weight (30kW is 19.5kg) for easy installation

Secure

Easy-fit wall mounting bracket featuring a positive fix and audible lock, so you know it’s secure

Time-saving

No pump overrun or permanent live required, saving time and money during installation

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Product Literature

Installation & Service Manuals

User Guides

Technical Specifications

Product Fiche

Energy Labels

Download the Baxi Residential Solutions guide

From boilers and cylinders to ASHPs and accessories, our Baxi Residential Solutions Guide gives you everything you need to deliver complete, reliable heating and hot water solution. Download it today to explore our full product portfolio.

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Dimensions

A: Boiler Width = 370mm

B: Boiler Height = 625mm

C: Boiler Depth = 270mm

D: Side Clearance = 5mm

E: Upper Clearance = 190mm*, 35mm* if used rear flue

F: Lower Clearance = 120mm*, 35mm* in 300m deep wall cupboard

G: Front Clearance= 5mm* in operation (500mm for servicing)

Technical Specification

Product Model	16	19	25	30
Product Code	7749866	7898832	7749868	7749869
Controls and accessories
Operating mode selector switch with reset (Yes/No)	Yes	Yes	Yes	Yes
User adjustable CH temperature (Range - e.g. 45° to 82°)	Yes	Yes	Yes	Yes
LED temp/status/fault diagnosis display (Yes/No)	Yes	Yes	Yes	Yes
Baxi twin channel wired programmer -7212443	Optional	Optional	Optional	Optional
Baxi room thermostat -720971601	Optional	Optional	Optional	Optional
Gas
Boiler Plus ErP (%)	93		93	93
SAP 2009 annual efficiency (PCDB/SEDBUK) %	89.2	89.2	89.1	89.1
NOx class	6	6	6	6
ErP Product Information
NOx (mg/kWh)	20	25	24	24
Sound Power Level, Indoors (LWA dB)	39	41	45	49
Space Heating Efficiency Class	A	A	A	A
Heat Input CH - kW max gross (QnHs)	18.32	21.75	28.62	34.35
Heat Input CH - kW min gross (QnHs)	8.59	8.59	8.59	8.59
Heat Output CH (non condensing) kW (Pn)	16	19	25	30
Heat Output CH (non condensing) kW (Pn)	7.5	6.4	7.5	7.5
Gas supply connection (mm)	22	22	22	22
Inlet supply pressure (natural gas) mbar	20	20	20	20
Maximum gas rate (m3/hr)	1.75	2.07	2.73	3.27
Mechanical and hydraulic
Compartment ventilation required (Yes/No)	No	No	No	No
Flow / return pipe size (mm)	22	22	22	22
Condensate discharge pipe size (mm)	21.5	21.5	21.5	21.5
Electrical
Electrical supply (Volts/Hz)	230V/50Hz	230V/ 50Hz	230V/50Hz	230V/50Hz
Permanent live required (Yes/No)	No	No	No	No
Switched live (Yes/No)	Yes	Yes	Yes	Yes
Electrical power cable fitted as standard (1m of 3 core)	Yes	Yes	Yes	Yes
Power consumption (Watts)	20	23	33	44
External fuse rating (Amps)	3	3	3	3
Internal fuse rating	1.6T	1.6T	1.6T	1.6T
Boiler IP rating (electrical protection) -Approval category	IPX4D	IPX4D	IPX4D	IPX4D
Pump overrun (Yes/No)	No	No	No	No
Concentric flue system
Standard telescopic concentric flue (Length in mm)	315-500	315-500	315-500	315-500
Horizontal and Vertical concentric (60/100 mm) - Max equivalent length (m)	6	6	6	6
Horizontal and Vertical concentric (60/100 mm) - Reduction per 135° bend (m)	0.5	0.5	0.5	0.5
Horizontal and Vertical concentric (60/100 mm) - Reduction per 93° bend (m)	1	1	1	1
Weights
Installer lift weight (boiler) Max (kg)	17.4	17.4	17.4	19.5
Gross packaged boiler weight (kg)	21.3	19.4	21.3	21.3

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If you are a merchant or installer, your local Baxi representative is here to help.

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More Information

Baxi Genuine Parts

Whether you are working on an installation, repair or service, Baxi Genuine Parts are guaranteed for quality, reliability and safety. Start here to find the parts you need.

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Product Training

Our training courses are held at our head office in Dublin, by experienced, qualified engineers who know what the job is like.

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Error Codes for Baxi Boilers

If a boiler develops a problem, it will display an error code. We explain the most common error codes here.

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Baxi Works

Baxi Works is our installer loyalty scheme, designed to prioritise you, support you and reward you for choosing Baxi.