Floor standing, high output condensing boiler with a stainless steel heat exchanger.

The range consists of 8 single boilers with outputs (at 50/30°C) of 127, 148, 191, 238, 290, 338, 415 and 478kW. Also available are 4 dual models with combined outputs (at 50/30°C) of 580, 676, 830 and 956kW.

 

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
BIM objects icon
  • Improved efficiency on split temperature systems due to high and low temperature return connections.
  • Non-dependent on system flow allowing wide differential temperatures.
  • Easier installation with no requirement for dedicated primary circuit and no minimum flow rates.
  • Tolerant to a wide range of system water conditions with a corrosion resistant stainless steel heat exchanger.
  • Long life backed up by a 5-year heat exchanger warranty.
  • Well insulated for low standby losses.
  • Maximum BREEAM credits available with NOx emissions lower than 40mg/kWh.
  • Match heating system loads accurately with outputs up to 900kW and a 5:1 turndown ratio.
  • Simplified flue system design as the flue gas non-return valve is built in to provide effective protection from re-circulation of flue gases through non-firing boilers.
  • Built in boiler sequence controls capable of controlling up to 16 boiler modules, multiple heating circuits and a hot water circuit using the master/slave principle.
  • Quick release access panels for ease of service and maintenance.
  Varmax Boiler Model Units 120 140 180 225 275 320 390 450 550 640 780 900
Energy Building regulations Part L seasonal efficiency % gross 96.13 96.13 96.33 96.33 96.24 96.24 96.22 96.22 96.24 96.24 96.22 96.22
Boiler output - maximum 80/60°C, NG & LPG. 390kW and 450kW models Nat Gas only. kW 117 136 175 219 268 312 381 439 536 624 762 878
Boiler output - maximum 50/30°C, NG & LPG. 390kW and 450kW models Nat Gas only. kW 127 148 191 238 290 338 415 478 580 676 830 956
Boiler output - minimum 80/60°C, Nat Gas. kW 27.3 27.2 41.8 41.8 64.3 64.3 85 84.7 64.3 64.4 85 84.9
Boiler output - minimum 80/60°C, LPG kW 38 37.8 61.3 61.3 87.6 87.7 N/A N/A 87.6 87.7 N/A N/A
Boiler input (gross) - maximum, NG & LPG. 390kW and 450kW models Nat Gas only. kW 120 140 180 225 275 320 390 450 550 640 780 900
Boiler input (net) - maximum, NG & LPG. 390kW and 450kW models Nat Gas only. kW 120 140 180 225 275 320 390 450 550 640 780 900
Standby loss W 182 182 213 213 259 259 311 311 518 518 622 622
Water Water content litres 116 116 151 151 239 239 287 287 478 478 574 574
System design flow rate @ 30°C ΔT rise l/s 0.9 1.1 1.4 1.7 2.1 2.5 3 3.5 4.3 5 6.1 7
Water side pressure loss @ 30°C ΔT rise mbar 27 33 25 36 36 53 34 43 36 53 34 43
System design flow rate @ 20°C ΔT rise l/s 1.4 1.6 2.1 2.6 3.2 3.7 4.6 5.3 6.4 7.4 9.1 10.5
Water side pressure loss @ 20°C ΔT rise mbar 60 75 57 81 82 119 77 97 82 119 77 97
System design flow rate @ 11°C ΔT rise l/s 2.5 2.9 3.8 4.7 5.8 6.8 8.3 9.5 11.6 13.5 16.5 19.1
Water side pressure loss @ 11°C ΔT rise mbar 198 248 188 268 271 393 255 321 271 393 255 321
Minimum water pressure barg 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5
Maximum water pressure barg 6 6 6 6 6 6 6 6 6 6 6 6
Minimum flow temperature setting °C 22 22 24 24 20 20 23 23 20 20 23 23
Maximum flow temperature setting °C 85 85 85 85 85 85 85 85 85 85 85 85
Gas Gas flow rate, NG (G20) - maximum m3/hr 12.7 14.8 19.1 23.8 29.1 33.9 41.3 47.6 58.2 67.7 82.6 95.2
Maximum gas inlet pressure, Nat Gas mbar 25 25 25 25 25 25 25 25 25 25 25 25
Nominal inlet pressure, Nat Gas mbar 20 20 20 20 20 20 20 20 20 20 20 20
Minimum gas inlet pressure, Nat Gas mbar 17 17 17 17 17 17 17 17 17 17 17 17
Gas flow rate, LPG (G31) - maximum m3/hr 4.9 5.7 7.4 9.2 11.3 13.1 N/A N/A 22.5 26.2 N/A N/A
Nominal inlet pressure, LPG mbar 37 37 37 37 37 37 N/A N/A 37 37 N/A N/A
Flue Approx. flue gas volume Nat Gas @ 15°C, 8.8–9.2% CO2 @ N.T.P m3/hr 167.5 195.2 251.8 313.8 383.7 447 544.6 627.6 767.4 894 1089.2 1255.2
Maximum flue gas temperature @ 80/60°C Nat Gas °C 60.8 62.1 61 62.3 61.7 63.4 62.5 64.8 61 60.8 60.3 62.1
Pressure at boiler flue spigot @ 80/60°C Pa mbar 200 200 115 165 122 176 180 193 127 151 177 200
Approx. flue gas volume LPG @ 15°C, 10.4–10.8% CO2 @ N.T.P m3/hr 153.9 179 232.4 288.9 354.9 411.4 N/A N/A 709.8 822.8 N/A N/A
Maximum flue gas temperature @ 80/60°C LPG °C 60.3 62.6 60.3 62.2 63 65.4 N/A N/A 62.8 64.7 N/A N/A
Pressure at boiler flue spigot @ 80/60°C LPG Pa mbar 167 200 103 136 118 157 N/A N/A 121 132 N/A N/A
Dry NOx emission (0% excess oxygen, mg/kWh dry air free); NG/(LPG) mg/kWh 30 30 30 30 40 40 35 35 40 40 35 35
Electrics Electrical supply   230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz 230V, 1Ph, 50Hz
Power consumption - maximum boiler modulation W 204 311 179 320 238 352 480 660 476 704 960 1320
Start current (per module) Amp 3.5 5.4 3.1 5.6 4.1 6.1 8.3 11.5 8.3 12.2 16.7 23
Run current (per module) Amp 0.89 1.35 0.78 1.39 1.03 1.53 2.09 2.87 2.07 3.06 4.17 5.74
  Approx shipping weight kg 340 340 393 393 502 502 592 592 1050 1050 1240 1240
  Noise emission @1m: @max. modulation dB (A) 65 65 61 61 61 61 68 68 61 61 68 68
  Title Type Size  
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  • Split temperature systems such as a combination of radiator loops/air convectors and underfloor heating.
  • Medium to large sized district heating schemes.
  • Schools.
  • Shopping centres.
  • Offices.
  • Sports facilities.
  • Health facilities.
  • A large range of off the shelf flue options available
  • Room sealed and open flue solutions
  • Flue header kits
  • Unvented kits

Single Boiler Controls

  • Outside air temperature sensor QAC34 (Part no. 533901457)
  • Domestic Hot Water sensor kit (sensor and pocket) QAZ36 (Part no. 563605674)
  • Mixing valve heating circuit control kit (AVS 75 control module, temperature sensor and pocket) for 1 zone (Part no. 059751)
  • 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. 563605673)
  • Merley boiler sequence controller, wall mounted (Part no. 563605672)
  • 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)