Potterton Promax SL Heat

The Potterton Promax SL Heat is a first-class, heat-only boiler that is suitable for both new build or replacement installations.

Suitable for

Social Housing

New Builds

Single boiler output
12kW, 15kW, 18kW and 24kW

Compact and light
Can be installed in a standard kitchen cupboard

No pump overrun
Quicker installation time for end user

Available in the choice of four outputs of 12kW, 15kW, 18kW and 24kW, the Promax SL Heat is small enough to fit in a standard kitchen unit and light enough for quick and easy installation.

The Potterton Promax SL Heat is a highly efficient heating solution with an excellent SAP 2012 rating and comes with a 2 year warranty as standard for complete peace of mind*. Installation can be made even faster with the use of a simple mounting plate, and is class 5 NOx as standard.

You can register your Potterton boiler online using Baxi's warranty registration form.

Terms and conditions apply.

Please note: warranty and purchasing information on this site applies to the UK only. For information on how to buy these products in the Republic of Ireland, please visit Baxi Potterton Myson.

  • 12kW, 15kW, 18kW, 24kW outputs available - a model to suit most sizes of property
  • N0x Class 5 - best in class
  • Compact and light -  can be installed in a standard kitchen unit
  • Simple mounting plate - for a quick and easy installation
  • No pump overrun - shortening installation time further
  • Pre-plumbing jig -  saving time on installation
  • Compatible with Megaflo Eco Solar Cylinder

Potterton Promax SL Heat

Units  12 15 18 24
Sales code 7219398 7219399 7219400 7219401


Reset button   Yes  Yes  Yes  Yes 


Gas (natural gas/LPG) NG NG NG NG
Inlet supply pressure mbar 20  20  20  20 
Maximum gas rate  m3/hr  1.34 1.64 1.94 2.31
Heat input central heating (CH)  kW Max Gross (QnHs)  13.34 16.88 20.18 24.5
kW Min Gross (QnHs)  10.2 10.2 10.2 10.2
Heat output CH non-condensing  kW Max (Pn)  11.82  15.24 17.81 22
kW min (Pn)  9.14 9.14 9.14 9.14
Heat output CH condensing 

kW max (Pnc) 

12.81 16.49 19.27 23.8
SAP 2009/2012 annual efficiency (PCDB/SEDBUK)  88.7 89.4 88.7  88.8 
NOx class   
View full technical specification table

Download the full technical specification for the Potterton Promax SL Heat

When clicked this will open the product specification in PDF format.

The following accessories and controls are compatible with the Potterton Promax SL Heat. To find out more, visit our Accessories and Controls page.

  • EP1 Programmer
  • EP2 Programmer
  • Multifit condensate trace heating kit 1m
  • Multifit condensate trace heating kit 2m
  • Multifit condensate trace heating kit 3m 
  • Multifit condensate trace heating kit 5m 
  • Multifit external boiler discharge pump (prv and condensate)

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Alternatively, speak to your Business Development Manager about this or any of our products.


Totally Dependable