Stratton mk 3 front facing 450 x 800 px
Stratton Mk3 LH facing_450x800
Stratton Mk3 RH facing pipe kit_450x800

Wall hung condensing boiler offering a small and durable solution suitable for even the tightest plant rooms.

Available in 7 models with outputs (at 50/30°C) of 40kW, 60kW, 70kW, 80kW, 100kW, 120kW, 150kW

Product information

    • A wide range of outputs enables you to specify the best wall hung boiler model for your commercial heating system
    • Single units can be cascaded for larger installations up to 900kW* 
    • Particularly suited to low height plantrooms, the boiler is less than 2 metres from the ground to the top of the frame when mounted on our low height pipe kit.
    • Outstanding efficiency in excess of 108% nett keeps operating costs to a minimum
    • Accurate load matching  with a high turndown ratio and fully modulating performance
    • Pre-mix burner technology gives clean operation with ErP Class 6 NOx emissions
    • Heat exchanger manufactured in corrosion resistant stainless steel for a long life, backed up by a 5-year heat exchanger warranty.
    • Built in boiler sequence controls capable of controlling up to 16 boiler modules and hot water circuits
    • Space saving flue arrangement above the boiler thanks to a concentric flue connector and integral flue gas non-return valve
    • Durable stainless steel heat exchanger, this boiler offers exceptional system tolerance
    • Full range of hydraulic separation options available
    • Easy access for service and system cleaning
    • Suitable for natural gas (all sizes) and LPG (up to 120kW) applications
    • Quick and easy to install with optional pipe kits for up to 6 boilers and wall mounting plate for individual boilers
    • Simple to move and store due to lightweight heat exchanger, and flat base of unit reduces risk of damaging connections
    • Suitable for use with room sealed or open flue systems giving you greater flexibility in siting the boilers
    • Simple to maintain using quick release internal water and gas couplings
    • A commercial boiler designed for sealed systems only for greater efficiency (you can read about the benefits of Sealed 'v' Open Vented heating systems here)
    • Low output models in the range for smaller applications


    * when using 6 Stratton mk3 boilers of 150kW in a cascade of 6. 

Technical data

Units S3-40
Building regulations Part L seasonal efficiency % gross 95.7
ErP efficiency rating (modules ≤ 70 kW only) A
Boiler output - maximum 80/60°C, NG & LPG kW 38.8
Boiler output - maximum 50/30°C, NG & LPG kW 42.2
Boiler output - minimum 80/60°C, NG & LPG kW 8
Standby losses W 52
Water content litres 3
System design flow rate @ 25°C ΔT rise l/s 0.38
Water side pressure loss @ 25°C ΔT rise mbar 223
System design flow rate @ 20°C ΔT rise l/s 0.48
Water side pressure loss @ 20°C ΔT rise mbar 459
System design flow rate @ 11°C ΔT rise l/s 0.87
Water side pressure loss @ 11°C ΔT rise mbar 1539
Minimum water pressure barg 1
Maximum water pressure barg 4
Maximum flow temperature setting °C 85
Gas flow rate, NG (G20) - maximum m³/hr 4.2
Maximum gas inlet pressure, Nat Gas mbar 25
Nominal gas inlet pressure, Nat Gas mbar 20
Minimum gas inlet pressure, Nat Gas mbar 17
Gas flow rate, LPG (G31) - maximum m3/hr 1.6
Nominal gas inlet pressure, LPG mbar 37
Maximum flue gas temperature @ 80/60°C Nat Gas °C 79
Dry NOx emission (0% excess oxygen, mg/kWh dry air free) mg/kWh 36
Electrical supply 230 V 1 Ph 50 Hz
Power consumption - maximum boiler modulation W 67
Approx shipping weight kg 45
Noise emission @1m: @maximum modulation dB (A) 50


Stratton mk3 product brochure

Product brochures 10012 kb

Stratton mk3 Frame and Header Kits Manual 80-150 kW (233247-4)

Installers guides 18822 kb

Stratton mk3 Magna1 Pumps 235522-3

Installers guides 1069 kb

Stratton mk3 Plate Heat Exchanger Kits Manual 233248-3

Installers guides 19923 kb

Stratton mk3 Retrofit Kit 233249-1

Installers guides 417 kb

Stratton mk3 UPMXXL Pump 235521-1

Installers guides 525 kb

Stratton mk3 frame & header kit 40-70kW

Installers guides 8718 kb

Stratton mk3 installation manual

Installers guides 12355 kb

Stratton mk3 schematics

Hydraulic schematics 631 kb

Stratton Mk3 - 40_70kW

CAD 1456 kb

Stratton Mk3 - 80_150kW

CAD 2615 kb

Stratton Mk3 DN100 1 Wide PipeKit Dimensional Drawing

CAD 1306 kb

Stratton Mk3 DN100 2 Wide PipeKit Dimensional Drawing

CAD 1911 kb

Stratton Mk3 DN50 1 Wide PipeKit Dimensional Drawing

CAD 1428 kb

Stratton Mk3 DN50 2 Wide PipeKit Dimensional Drawing

CAD 2167 kb

Stratton Mk3 DN80 1 Wide PipeKit Dimensional Drawing

CAD 1327 kb

Stratton Mk3 DN80 2 Wide PipeKit Dimensional Drawing

CAD 1987 kb

Hamworthy PHEX 150kW tech submittal sheet

164 kb

Hamworthy PHEX 300kW tech submittal sheet

163 kb

Hamworthy PHEX 450kW tech submittal sheet

148 kb

Hamworthy PHEX 50kW tech submittal sheet

160 kb

Hamworthy PHEX 600 kW tech submittal sheet

153 kb

Hamworthy PHEX 60kW tech submittal sheet

147 kb

Hamworthy PHEX 900kW tech submittal sheets

160 kb

Technical Submital Sheet_Stratton mk3 S3-40, S3-60, S3-70_260723.pdf

172 kb

Technical Submital Sheet_Stratton mk3 S3-80, S3-100, S3-120, S3-150_260623.pdf

173 kb

Ideal uses/applications

Optional extras

Often bought with

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Halstock stainless steel calorifier

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Case studies

Hull & East Yorkshire Centre for the Deaf

Sector: Independent charity

Project: The Hull & East Yorkshire Centre for the Deaf is a registered charity that has been providing valuable support and social events for the local deaf community since 1926. With a heating system that was reaching the end of its life, we offered the charity the opportunity upgrade to the new Stratton Mk3.

Building: Building refurbishment

Application: Space heating

Learn more