Wall hung condensing commercial boiler with a stainless steel heat exchanger.

Available in 7 models with outputs (at 50/30°C) of 43, 61, 76, 87, 104, 129 and 146kW.

 

Efficiency 96 product icon
Fuel NG LPG product icon
Turndown 5 product icon
Warranty 5 heat exchanger product item
ErP Part L Compliant product icon
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  • A wide range of outputs enables you to specify the best wall hung boiler model for your commercial heating system.
  • Accurate load matching  with a high turndown ratio and fully modulating performance.
  • 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.
  • Low height - less than 2.2 metres to top of flue header when mounted on Hamworthy low height pipe kit. 
  • Space saving flue arrangement above the boiler thanks to a concentric flue connector and integral flue gas non-return valve.
  • Models up to 129kW meet the strict energy saving criteria for the Government’s Energy Technology List (ETL), providing significant financial advantages for purchasers through the Enhanced Capital Allowances (ECA) scheme.
  • Quick and easy to install with optional pipe kits for up to 4 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.
  • Low output models in the range for smaller applications.
  • Buy in confidence from a UK manufacturer with decades of commercial heating and hot water expertise.
  • Extensive back up and support from our team of experienced engineers across the UK.
  • Long term commitment to boiler spare parts
  Stratton mk2 boiler model Units S2-40 S2-60 S2-70 S2-80 S2-100 S2-120 S2-150
Energy Building regulations Part L seasonal efficiency % gross 95.75 96.13 95.5 95.5 96.02 95.95 95.75
SAP 2009 Annual efficiency % 89 89.2 88.8 88.8 89.1 89.1 89
ErP efficiency rating (modules ≤ 70 kW only) A A A N/A N/A N/A N/A
Boiler output - maximum 80/60°C, NG & LPG. (S2-120 & S2-150 models Nat Gas only.) kW 40 56.4 69.9 79.8 95.7 119.5 134
Boiler output - maximum 50/30°C, NG & LPG. (S2-120 & S2-150 models Nat Gas only.) kW 43 61 76.8 87.5 104.5 129.5 146
Boiler output - minimum 80/60°C, Nat Gas. kW 8.3 11.5 17.1 17.1 19 23.9 26.8
Boiler output - minimum 80/60°C, LPG kW 8.3 11.5 31.9 31.9 33.5 N/A N/A
Boiler input (gross) - maximum, NG & LPG. (S2-120 & S2-150 models Nat Gas only.) kW 45.7 64.4 80 91.3 109.3 136.5 151.6
Boiler input (nett) - maximum, NG & LPG. (S2-120 & S2-150 models Nat Gas only.) kW 41.2 58 72.1 82.3 98.5 123 137.9
Standby losses W 42 51 87 87 94 104 117
Water Water content litres 3.6 5 9 9 10.2 12.8 15.3
System design flow rate @ 25°C ΔT rise l/s 0.4 0.5 0.7 0.8 0.9 1.1 1.3
Water side pressure loss @ 25°C ΔT rise mbar 205 224 176 205 246 314 380
System design flow rate @ 20°C ΔT rise l/s 0.5 0.7 0.8 0.9 1.1 1.4 1.6
Water side pressure loss @ 20°C ΔT rise mbar 320 350 275 320 385 490 580
System design flow rate @ 11°C ΔT rise l/s 0.9 1.2 1.5 1.7 2.1 2.6 2.9
Water side pressure loss @ 11°C ΔT rise mbar 1058 1157 909 1058 1273 1620 1700
Minimum water pressure barg 1.5 1.5 1.5 1.5 1.5 1.5 1.5
Maximum water pressure barg 4 4 4 4 4 4 4
Maximum flow temperature setting °C 85 85 85 85 85 85 85
Gas Gas flow rate, NG (G20) - maximum m3/hr 4.4 6.1 7.6 8.7 10.4 13 14.6
Maximum gas inlet pressure, Nat Gas mbar 25 25 25 25 25 25 25
Nominal gas inlet pressure, Nat Gas mbar 20 20 20 20 20 20 20
Minimum gas inlet pressure, Nat Gas mbar 17 17 17 17 17 17 17
Gas flow rate, LPG (G31) - maximum m3/hr 1.7 2.4 3 3.4 4 N/A N/A
Nominal gas inlet pressure, LPG mbar 37.5 37.5 37.5 37.5 37.5 N/A N/A
Flue Approx. flue gas volume Nat Gas @ 15°C, 9.1–9.3% CO2 @ N.T.P m3/hr 57 79 98 112 135 168 189
Maximum flue gas temperature @ 80/60°C Nat Gas °C 80 76 70 74 76 70 70
Pressure at boiler flue spigot @ 80/60°C Nat Gas Pa 156 200 123 179 187 200 200
Approx. flue gas volume LPG @ 15°C, 10.3–10.5% CO2 @ N.T.P m3/hr 55 77 96 109 128 N/A N/A
Maximum flue gas temperature @ 80/60°C LPG °C 81 78 69 73 75 N/A N/A
Pressure at boiler flue spigot @ 80/60°C LPG Pa 126 200 105 150 138 N/A N/A
Dry NOx emission (0% excess oxygen, mg/kWh dry air free) mg/kWh 36 35 35 35 34 36 35
Electrics Electrical supply 230V 1Ph 50Hz
Power consumption - maximum boiler modulation W 68 138 96 141 160 206 263
Start current (per module) Amp 1.2 2.4 1.68 2.8 3.2 4 4.5
Run current (per module) Amp 0.3 0.6 0.42 0.61 0.7 0.9 1.14
Approx shipping weight kg 50 60 90 90 95 100 125
Noise emission @1m: @maximum modulation dB (A) 57.4 59.7 57.3 57.3 58.5 61.6 59.3
Noise emission @1m: @minimum modulation dB (A) 34.3 35.8 33.5 33.5 34.3 35.4 36.8
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  • New build and retrofit projects.
  • Smaller commercial and public buildings including community schools, care homes, hotels, churches and retail units.
  • Small industrial and manufacturing premises.
  • A large range of off the shelf flue options available.
  • Room sealed and open flue solutions.
  • Choice of pipe kits with low loss header.
  • Support frame kit.
  • Flue header kits.

Single Boiler Controls

  • Outside air temperature sensor QAC34 (Part no. 533901457).
  • Domestic Hot Water sensor kit (sensor and pocket) (Part no. 563605674).
  • Mixing valve heating circuit control kit (clip in control module, temperature sensor and pocket) for 1 zone (Part no. 059753) – Maximum 2 kits per boiler.
  • Programmable room sensor QAA75 (Part no. 533901587).
  • Offset adjustable room sensor QAA55 (Part no. 533901589).

Multiple Boiler Controls

  • Outside air temperature sensor QAC34 (Part no. 533901457).
  • Heating circuit sensor kit (sensor and pocket) QAZ36 (Part no. 563605609).
  • Merley boiler sequence controller, wall mounted (Part no. 563605672).
  • Merley boiler sequence controller, loose kit for panel mounting (Part no. 563605671).
  • LPB Bus communication module OCI345, one required per boiler module (Part no. 563605667).
  • Programmable room sensor QAA75 (Part no. 533901587).
  • Offset adjustable room sensor QAA55 (Part no. 533901589).