Stainless steel high efficiency, fully modulating condensing pre-mix floor standing boiler.

Available in 5 modules with outputs (@80/60°C) of 97, 116, 147, 196 and 254kW. Individual boiler modules can be stacked one, two or three high in 15 combinations up to 762kW output.

 

Efficiency 95 product icon
Fuel NG LPG product icon
Turndown 15 product icon
Warranty 10 heat exchanger product item
ErP Part L Compliant product icon
BIM objects icon
  • Fully modulating boiler which benefits from lower fuel usage and closer load matching.
  • Space-saving stacked module design delivering 762kW in less than a square metre footprint.
  • Flexibility in system design with differential temperature (delta T) up to 40°C. Suited to district heating schemes, the lower flow rates associated with wider differential temperature allow smaller diameter pipes and smaller pumps that can lower capital cost and also reduce energy consumption.
  • Compensate for distribution losses in large heating systems with max 90°C flow temperature.
  • 10 bar maximum working pressure allows installation in basement for high rise buildings.
  • Stainless steel heat exchanger backed up by with a 10-year warranty, making the Wessex ModuMax mk3 an extremely robust boiler.
  • High relative velocity within the waterways help to reduce the opportunity for sedimentation.
  • Low water content, rapid response, with minimal standing losses.
  • Built in boiler sequence controls capable of controlling up to 16 boiler modules and hot water circuits.
  • Low environmental impact - NOx <40mg/kWh for maximum BREEAM credits.
  • Easy access to plant room as the lightweight and compact Wessex ModuMax mk3 fits through a standard doorway and can split into modules for limited access or rooftop plant rooms, as well as packaged plant rooms.
  • Buy in confidence from a UK manufacturer with decades of commercial heating and hot water expertise.
  • Back up and support from our team of experienced engineers across the UK.
  • Extensive boiler spare parts service available direct from the manufacturer.
  Wessex ModuMax mk3 boiler model Units 97/97H 97/194V 97/291V 116/116H 116/232V 116/348V 147/147H 147/294V 147/441V 196/196H 196/392V 196/588V 254/254H 254/508V 254/762V
  No. of modules   1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
Energy Building regulations Part L seasonal efficiency % gross 94.98 94.98 94.98 93.19 93.19 93.19 94.76 94.76 94.76 94.98 94.98 94.98 93.19 93.19 93.19
Boiler output 80/60°C, NG & LPG kW 95.7 191.4 287.1 115.2 230.4 345.6 142.8 285.6 428.4 191.6 383.2 574.8 239.8 479.6 719.4
Boiler output 50/30°C, NG & LPG kW 97.2 194.4 291.6 116.2 232.5 348.7 147.4 294.8 442.2 196.3 392.6 588.9 254.4 508.7 763.1
Boiler input (gross) - maximum, NG kW 109 218 327 133 266 399 163 326 489 219 428.7 657 275 550 825
Boiler input (gross) - maximum, LPG kW 106.7 213.4 320.1 130.2 260.4 390.5 159.5 319.1 478.6 214.4 428.7 643.1 269.2 538.3 807.5
Boiler input (net) - maximum, NG & LPG kW 98.2 196.4 294.6 119.8 239.6 359.4 146.8 293.6 440.3 197.2 394.4 591.6 247.6 495.3 742.9
Boiler output - minimum 80/60°C, NG & LPG kW 19.1 19.1 19.1 23.5 23.5 23.5 28.7 28.7 28.7 38.6 38.6 38.6 48.4 48.4 48.4
Water Water content litres 16 32 48 16 32 48 22 44 66 22 44 66 22 44 66
System design flow rate @ 40°C ∆T rise l/s 0.6 1.2 1.8 0.7 1.4 2.1 0.9 1.8 2.7 1.2 2.4 3.6 1.5 3 4.5
Water side pressure loss @ 40°C ∆T rise mbar 5 5 5 7 7 7 36 36 36 62 62 62 100 100 100
System design flow rate @ 30°C ∆T rise l/s 0.8 1.6 2.4 1 2 3 1.2 2.4 3.6 1.6 3.2 4.8 2 4 6
Water side pressure loss @ 30°C ∆T rise mbar 9 9 9 14 14 14 60 60 60 120 120 120 180 180 180
System design flow rate @ 20°C ∆T rise l/s 1.2 2.4 3.6 1.4 2.8 4.2 1.8 3.6 5.4 2.4 4.8 7.2 3 6 9
Water side pressure loss @ 20°C ∆T rise mbar 20 20 20 27 27 27 145 145 145 246 246 246 395 395 395
System design flow rate @ 11°C ∆T rise l/s 2.2 4.4 6.6 2.6 5.2 7.8 3.3 6.6 9.9 4.3 8.6 12.9 5.4 10.8 16.2
Water side pressure loss @ 11°C ∆T rise mbar 61 61 61 91 91 91 500 500 500 850 850 850 1300 1300 1300
Minimum water pressure barg Dependent on differential temperature – see page 25 Dependent on differential temperature – see page 25
Maximum water pressure barg 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10
Maximum flow temperature setting °C 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
Gas Gas flow rate, NG (G20) - maximum m3/hr 10.8 21.6 32.4 12.7 25.4 38.1 16 32 48 21.4 42.8 64.2 27.9 55.8 83.7
Gas flow rate, LPG (G31) - maximum m3/hr 4 8 12 5 10 15 6 12 18 8.1 16.2 24.3 10.1 20.2 30.3
Nominal inlet pressure, NG (LPG) - maximum mbar 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37) 20 (37)
Maximum gas inlet pressure NG (LPG) mbar 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45) 25 (45)
Flue Approx. flue gas volume @ 15°C, 8.75-9.25% CO2 m3/hr 143 286 429 160 320 480 214 428 642 279 558 837 354 708 1062
Maximum flue gas temperature @ 80/60°C °C 83 83 83 83 83 83 78 78 78 83 83 83 82 82 82
Pressure at boiler flue connection Pa mbar 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5 150 1.5
Dry NOx emission (0% excess oxygen, dry air free) - NG mg/kWh 39.8 39.8 39.8 34.3 34.3 34.3 37.7 37.7 37.7 39.9 39.9 39.9 38.8 38.8 38.8
Dry NOx emission (0% excess oxygen, dry air free) - LPG mg/kWh 42 42 42 57.3 57.3 57.3 69.3 69.3 69.3 68.6 68.6 68.6 39.9 39.9 39.9
Connection Water flow/return connections inches G1½" male G1½" male G1½" male G1½" male G1½" male G1½" male G2½" male G2½" male G2½" male G2½" male G2½" male G2½" male G2½" male G2½" male G2½" male
Gas inlet connection pipe thread size inches R1" male R1" male R1" male R1" male R1" male R1" male R1¼" male R1¼" male R1¼" male R1¼" male R1¼" male R1¼" male R1¼" male R1¼" male R1¼" male
Nominal flue diameter (I/D) mm 100 180 180 100 180 180 150 250 250 150 250 250 150 250 250
Condensate trap connection(s) (O/D) mm 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32
Electrics Electrical supply 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz 230 V 1 Ph 50 Hz
Power consumption - maximum boiler modulation W 166 332 498 166 332 498 240 480 720 240 480 720 240 480 720
Start current (per module) Amp 1.2 1.2 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3
Run current (per module) Amp 0.72 0.72 0.72 0.72 0.72 0.72 1.05 1.05 1.05 1.05 1.05 1.05 1.05 1.05 1.05
Approx shipping weight kg 180 355 540 180 355 540 226 452 678 226 452 678 226 452 678
Noise emission @1m @maximum modulation Max dB (A) 60 60 60 60 60 60 65 65 65 65 65 65 65 65 65
Noise emission @1m @minimum modulation Min dB (A) 47 47 47 47 47 47 47 47 47 47 47 47 47 47 47
  Title Type Size  
Wessex ModuMax mk3 boiler brochure Wessex ModuMax mk3 boiler brochure Product brochures 8727 ko Download
Wessex Modumax mk3 dimensions Wessex Modumax mk3 dimensions Dimensions 629 ko Download
Wessex Modumax mk3 technical data table Wessex Modumax mk3 technical data table Data tables 126 ko Download
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Volt Free Contact (VFC) and switch fitting instructions Volt Free Contact (VFC) and switch fitting instructions Installers guides 1349 ko Download
Wessex ModuMax mk3 Installers Guide Wessex ModuMax mk3 Installers Guide Installers guides 6681 ko Download
Wessex ModuMax mk3 user instructions Wessex ModuMax mk3 user instructions Installers guides 76 ko Download
Wessex ModuMax mk3 scheme 1 open vented with low loss header Wessex ModuMax mk3 scheme 1 open vented with low loss header Hydraulic schematics 78 ko Download
Wessex ModuMax mk3 scheme 2 sealed primary with open vented second and plate heat exchanger Wessex ModuMax mk3 scheme 2 sealed primary with open vented second and plate heat exchanger Hydraulic schematics 71 ko Download
Wessex ModuMax mk3 scheme 3 single pipe,  pump per boiler and LLH Wessex ModuMax mk3 scheme 3 single pipe, pump per boiler and LLH Hydraulic schematics 73 ko Download
Wessex ModuMax mk3 scheme 4, single pipe with independent DHW Wessex ModuMax mk3 scheme 4, single pipe with independent DHW Hydraulic schematics 86 ko Download
Wessex ModuMax mk3 boiler 116-116H CAD Wessex ModuMax mk3 boiler 116-116H CAD CAD 2040 ko Download
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Wessex ModuMax mk3 boiler 196-392V CAD Wessex ModuMax mk3 boiler 196-392V CAD CAD 3155 ko Download
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  • Energy centres within district heating schemes and larger premises.
  • Housing developments and flats using district heating networks.
  • Hybrid systems alongside combined heat and power (CHP) and/or other renewable technologies such as biomass boilers.
  • Easy fit replacement for refurbishment projects.
  • Roof top and basement plantrooms.
  • Packaged plantrooms.
  • New build projects.
  • Large commercial and public buildings including schools, hospitals and hotels.
  • Medium sized commercial and public buildings including schools, hospitals, offices and hotels.
  • Small industrial and manufacturing premises.
  • Locations with substantial and continuous heating load including hospitals, care homes and hotels.
  • Pipework kits to match the boiler model for ease of installation on site.
  • Flues available through our flue partner Midtherm Engineering
  • Choose from a wide range of service contracts to help maintain optimum performance.
  • Book commissioning at the same time as placing your order for improved warranty terms.

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. 563605668).
  • Mixing valve heating circuit control kit (clip in control module, temperature sensor and pocket) for 2 zones (Part no. 563605669).
  • Mixing valve heating circuit control kit (clip in control module, temperature sensor and pocket) for 3 zones – Note: cannot be used in conjunction with volt free contact kit (Part no. 563605670).
  • 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).
  • Volt free contact kit for remote status signalling AGU2.550A109 (Part no. 563605666).
  • Heating circuit sensor kit (sensor and pocket) QAZ36 (Part no. 563605673).
  • 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).