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Potterton Promax Ultra

The Potterton Promax Ultra Combi has been designed specifically for social housing and new build projects.

Suitable for

Social Housing

New Builds

Promax Ultra product image

Single boiler output
24kW, 28kW, 33kW and 40kW

40kW model available
Delivering a higher domestic flow rate for larger properties

Flueing options
Up to 20 metres

Available in outputs of 24kW, 28kW, 33kW and 40kW, the Potterton Promax Ultra Combi delivers domestic hot water flow rate up to 16.4 litres/minute and has  an excellent SAP 2012 seasonal efficiency rating for cost effective compliance with the Building Regulations.

The Promax Ultra comes with built-in frost protection and flueing options up to 20 metres so it can be installed almost anywhere, offering greater siting flexibility.

To register a Potterton Promax Ultra boiler online, click here 

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.

  • Energy Saving Trust Endorsed
  • 24kW, 28kW, 33kW and 40kW models available - a model to suit most sizes of property
  • 40kW model - delivers a higher domestic hot water flow rate for larger properties
  • SAP 2012 seasonal efficiency figure  - for cost effective building regulations compliance
  • N0x Class 5 - best in class
  • Flueing options of up to 20m - offering flexibility for a variety of different housing projects.
  • One boiler to suit both fuel types -  no conversion kit required
  • Pre-plumbing jig -  saving time on installation.

Potterton Promax Ultra Combi 


Units  24  28  33  40 
Sales code 7223762  7223763  7223764  7223765 


Concealed user controls    Yes  Yes   Yes   Yes  
On/off switch with reset    Yes   Yes   Yes   Yes  
User adjustable DHW temperature    Yes   Yes   Yes   Yes  
User adjustable CH temperature    Yes   Yes   Yes   Yes  
LED temp/status/fault diagnosis display    Yes   Yes   Yes   Yes  
Integral 24hr electro-mechanical timer    No  No  No  No 


Natural gas  mbar  Yes  Yes  Yes  Yes 
Nominal inlet supply pressure m3/h  20  20  20  20 
Maximum gas rate    2.61  3.05  3.59  4.35 
Propane LPG  mbar  Yes   Yes   Yes   Yes  
Nominal inlet supply pressure  kg/h  20  20  20  20 
Maximum gas rate  kg/h  1.69  2.29  2.70  3.27 
Heat input central heating (CH)  kW Max Gross (QnHs)  22.20  26.64  31.08  35.52 
kW Min Gross (QnHs)  3.89  4.32  5.33  6.55 
Heat output CH non-condensing  kW Max (Pn)  20.00  24.00  28.00  32.00 
kW min (Pn)  3.40  3.80  4.70  5.70 
Heat output CH condensing  kW max (Pnc)  21.20  25.30  29.60  33.80 
kW min (Pnc)  3.70  4.10  5.10  6.20 
Heat input domestic hot water  kW Max Gross (QnwHs)  27.40  32.10  37.80  45.80 
Heat output domestic hot water  kW Max (Pn)  24.00  28.00  33.00  40.00 
Maximum domestic hot water flow rate  I/min @ 35°C rise  9.8  11.5  13.5  16.4 
SAP 2009/2012 annual efficiency (PCDB/SEDBUK)  89.1  89.1  89.1  89.1 
NOx class   
View full technical specification table

Download the full technical specification for the Potterton Assure Combi

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

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

  • Programmable 7 day wireless sensor (2 channel)
  • Programmable 24hr wireless sensor (single channel)
  • Stand off kit (facilitates vertical pipe runs behind boiler)
  • Multifit gas saver (natural gas)
  • Multifit (gas saver) expansion vessel kit
  • Gas saver - stand off kit
  • 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)
  • Terminal guard ∅ 60/100
  • Stainless steel PDK guard ∅ 60/100 - air intake S/S

Interested in this product for your premises? Complete the form below and someone from the team will contact you shortly.

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


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