The P Series is our range of three-pass cast iron sectional boilers. Perfect for use with gas and dual fuel through a pressure jet burner for commercial and industrial applications.
Designed on the basis of the triple-pass principle to achieve maximum efficiency, while the generously sized chamber allows optimal combustion and minimum NOx and CO2 emissions.
Compact yet extremely powerful, the P Series is available in two ranges:
P420 and P520 (the P320 is suitable for replacement projects only)
If you need support choosing the best Pressure Jet solution for your project, just contact our team of dedicated experts who will talk you through the range.
- Pressure Jets
- P Series
- Home
- Products
- Pressure Jets
- P Series

Features and Benefits
Maximise efficiency
Triple-pass flueways design to maximise efficiency
Low emissions
The large combustion chamber minimises NOx and CO2 emissions
Resistance to temperature variations
The eutectic cast iron boiler body provides exceptional resistance to temperature variations, thermal shocks and corrosion
Improves thermal efficiency
Reinforced fibreglass wool insulation and double insulation of the boiler front minimises heat loss and improves thermal efficiency
Easy installation
Time-saving easy installation for new and existing plant room
Pre-set water flow switch
P520 is delivered as standard with pre-set water flow switch for a quick, easy installation
Show More
Show Less
Product Literature
Installation & Service Manuals
Technical Specifications
Technical Specifications
Product Documentation
Technical Specification
Model | 9-Section | 10-Section | 11-Section | 12-Section | 13-Section | 14-Section |
Performance | ||||||
Nominal heat output central heating operation | 450 | 540 | 600 | 670 | 720 | 780 |
@ 80/60°C kW (min-max)* | ||||||
Efficiency | ||||||
Efficiency – full load 100% NCV | 88% | 88% | 88% | 88% | 88% | 88% |
Seasonal efficiency GCV | 82.2% | 82.2% | 82.2% | 82.2% | 82.2% | 82.2% |
Burner type/Pressure jet | ||||||
Standard fuel | Natural gas/(35 sec) | Natural gas/(35 sec) | Natural gas/(35 sec) | Natural gas/(35 sec) | Natural gas/(35 sec) | Natural gas/(35 sec) |
/dual fuel | /dual fuel | /dual fuel | /dual fuel | /dual fuel | /dual fuel | |
Max gas consumption | Check burner details | Check burner details | Check burner details | Check burner details | Check burner details | Check burner details |
Oil consumption kg/hr @ 12 bar pump pressure | 43.33 | 52 | 57.77 | 64.52 | 63 | 75.11 |
Min op gas pressure mbar | Check burner details | Check burner details | Check burner details | Check burner details | Check burner details | Check burner details |
Flue (conventional connection) | ||||||
Flue diameter mm I/D | 250 | 250 | 300 | 300 | 300 | 300 |
Chamber resistance mbar | +1.5 | +2.0 | +2.5 | +2.5 | +2.5 | +3.5 |
Flue gas flow rate kg/h gas | 810 | 972 | 1080 | 1207 | 1297 | 1450 |
Min/max flue gas flow rate g/s | 4.1-15.1 | 4.1-20.7 | 5.9-30.1 | 6.5-39.5 | 8.0-52.8 | 76.9 max |
Average flue gas temperature boiler | less than 220 | less than 220 | less than 220 | less than 220 | less than 220 | less than 220 |
temperature 80°C | ||||||
Flue gas flow rate kg/h oil (full output 80/60°C) | 750 | 900 | 1000 | 1116 | 1200 | 1405 |
Hydraulics | ||||||
Water content litres | 409 | 452 | 495 | 538 | 581 | 624 |
Resistance @ 11°C ΔT mbar | 39.7 | 66 | 82.6 | 109.2 | 132.17 | 162.23 |
Hydraulic resistance @ 20°C ΔT mbar | 12 | 20 | 25 | 33 | 40 | 49 |
Nominal flow rate @11°C ΔT l/s | 9.77 | 11.73 | 13.03 | 14.55 | 15.64 | 16.94 |
Nominal flow rate @ 20°C ΔT l/s | 5.38 | 6.45 | 7.17 | 8.0 | 8.6 | 9.32 |
Min. flow rate l/s based on a ΔT of 45°C | 2.39 | 2.85 | 3.18 | 3.54 | 3.8 | 4.12 |
Connection size BSP | 2.5" Flanged | 2.5" Flanged | 3" Flanged | 3" Flanged | 3" Flanged | 3" Flanged |
Standard operating temperature °C ** | 80 | 80 | 80 | 80 | 80 | 80 |
Max operating temperature °C | 90 | 90 | 90 | 90 | 90 | 90 |
Max water temperature °C | 110 | 110 | 110 | 110 | 110 | 110 |
Max water operating pressure bar | 6 | 6 | 6 | 6 | 6 | 6 |
Test press bar | As per assembly | As per assembly | As per assembly | As per assembly | As per assembly | As per assembly |
manual | manual | manual | manual | manual | manual | |
Minimum return temperature °C | 50 | 50 | 50 | 50 | 50 | 50 |
High limit set point °C | 110 | 110 | 110 | 110 | 110 | 110 |
General | ||||||
Shipping weight (kg) | 1650 | 1830 | 2010 | 2190 | 2370 | 2550 |
Dimension (WxHxD inc. flow, return and | 1000 x 1690 x 1950 | 1000 x 1690 x 2120 | 1000 x 1690 x 2305 | 1000 x 1690 x 2465 | 1000 x 1690 x 2625 | 1000 x 1690 x 2785 |
gas pipework mm) | ||||||
Noise levels dB(A) at 1 metre | check burner details | check burner details | check burner details | check burner details | check burner details | check burner details |
Minimum operating gas pressure | check burner details | check burner details | check burner details | check burner details | check burner details | check burner details |
Radiated losses (w) based on ΔT 45°C | 358 | 413 | 451 | 494 | 505 | 555 |
Combustion chamber diameter | 530 | 530 | 530 | 530 | 530 | 530 |
Electrical | ||||||
Nominal power supply | 230v x1ph x 50hz | 230v x1ph x 50hz | 230v x1ph x 50hz | 230v x1ph x 50hz | 230v x1ph x 50hz | 230v x1ph x 50hz |
Fuse rating (amps) | 10 | 10 | 10 | 10 | 10 | 10 |
*Gas consumption based on lower heating value under standard heating conditions: T=288.15K, p=1013.25mbar. Gag 30.33, G25 29.25, G31 88.00 MJ/m3
**Open vented option maximum operating temperature 75°C
Note: 1 ph burners obtain their power supply via the boiler. Fuse rating amps: 10.4 mp 3ph burners require a 3ph supply + 1ph to the boiler
Contact your Dedicated Expert
Get in touch with our experts for product enquiries or to get a quote.