Ensbury pressure jet boiler
Ensbury pressure jet boiler heat exchanger

Low temperature, high efficiency, floor standing steel boiler.

Available in 3 models with outputs (at 80/60°C) of 440, 510 and 580kW.

Efficiency 86 product icon
Fuel NG LPG oil biofuel dualfuel product icon
Turndown 3 product icon
Warranty 2 product item

Product information

    • Advanced return distribution within boiler allows operation with return temperatures as low as 15°C. (Minimum flow temperatures apply).
    • Operating efficiencies of up to 95% nett (86% gross) at part load.
    • Suitable for use on open vented or sealed low temperature hot water heating systems .
    • Robust three-pass heat exchanger design helps to achieve European Class 5 performance for NOx emissions.
    • Suitable for use with liquid biofuel as a renewable energy choice. Natural Gas, LPG (propane) or oil are other fuel options.
    • Extensive back up and support from our team of experienced engineers across the UK.
    • Long term commitment to spare parts.

Technical data

Units ELT440
Building regulations Part L seasonal efficiency % gross 85.05
Boiler output 80/60°C kW 440
Boiler input (gross) - maximum kW 537
Boiler input (nett) - maximum kW 483
Boiler output - minimum 80/60°C, NG kW 100
Boiler output - minimum 80/60°C, oil kW 127
Water content litres 540
System design flow rate @ 20°C ∆T rise l/s 5.26
Water side pressure loss @ 20°C ∆T rise mbar 20
System design flow rate @ 10°C ∆T rise l/s 10.53
Water side pressure loss @ 10°C ∆T rise mbar 81
Water flow rate - minimum l/s No min flow rate
Minimum water pressure barg 0.5
Maximum water pressure barg 4
Maximum water flow temperature °C 90
Minimum water flow temperature - NG °C 60
Minimum water flow temperature - oil °C 50
Minimum water return temperature °C 15
Gas flow rate, NG - maximum m3/hr 51.2
Inlet pressure for NG - nominal mbar 20
Inlet pressure for NG - maximum mbar 50
Input rate for oil (35sec) l/h 50.8
Approx. flue gas volume @ 15°C, 9% CO2, N.T.P m3/hr 614.9
Flue gas temperature @ 80/60°C °C 182
Combustion chamber resistance mbar 2.53
Water flow/return connections PN6 - DN80
Gas inlet connection pipe thread size Rc1 ½"
Safety valve connection Rc1 ½"
Drain connection R1"
Flue diameter (O/D) - nominal mm 250
Electrical supply for boiler 230V 1Ph 50Hz
Electrical supply for burner 230V 1Ph 50Hz*
Approx shipping weight (excluding burner) kg 973
*400V 3Ph 50Hz Dependant on burner selection


Ensbury LT boiler brochure

Product brochures 10320 kb

Ensbury LT boiler installation manual

Installers guides 1877 kb


Hamworthy’s Ensbury LT boilers were selected for their size, capacity, and the innovative low temperature management system, which is ideally suited for this unique project

Malcolm Hunt, Senior Engineer, Mabey Francis

We had numerous problems with the previous boiler so turned to Hamworthy to provide us with a reliable, long-lasting and high efficiency boiler solution. The Ensbury boilers suited the brief perfectly.

Sandy Yogendra, Mechanical design engineer, Islington Council

Ideal uses/applications

Optional extras

  • Can be installed with the Arne flue gas economiser to increase operating efficiency by up to 18%.
  • 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. 
  • Flues available through our flue partner Jeremias UK.

Often bought with

Arne flue gas economiser

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Powerstock glass lined calorifier

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Merley boiler sequence controller

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Case studies

Pitfield Street is a mixed used development which now benefits from a liquid biofuel boiler.

Pitfield Street, London

Sector: Residential and commercial

Project: A 100% liquid biofuel boiler proved to be the greenest heating option for a city centre development consisting of 16 flats and a commercial unit.

Building: New build flats and retail space

Application: Space heating. Renewable energy

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Drayton Manor benefits from Hamworthy high efficiency steel shell boilers and direct-fired condensing water heaters.

Drayton Manor Hotel, Staffordshire

Sector: Hotel and leisure

Project: Guests benefit from the installation of three new Dorchester DR-FC Evo water heaters and two Ensbury LT 370 low temperature steel boilers.

Building: New build hotel

Application: Domestic hot water, 5787 litres/hour. Space heating, 740kW

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Christchurch Police Station installed four of Hamworthy's oil-fired steel boilers.

Christchurch Police Station

Sector: Public sector

Project: Steel boilers from Hamworthy were the ideal solution for this dual-purpose building in Dorset.

Building: Dual-purpose building – police station and adult education centre

Application: Space heating

Learn more