Low output direct fired atmospheric water heater for domestic hot water generation.

4 models available with continuous outputs (@44°C ∆T) of 369 and 392 l/h.

Due to the Energy-related Products (ErP) Directive regulations we have a limited stock available of atmospheric water heaters. Talk to us today to secure your product or find out about availability.

Efficiency 76 product icon
Fuel NG LPG product icon
Warranty 2 product item
Part L compliant product icon
  • Can be installed close to the point of use.
  • Ideal for applications where hot water demand is low.
  • Choose from fully automatic ignition with flame detection (DR-SA) or permanent pilot with thermocouple (DR-SE).
  • Natural gas and lpg water heater options.
  • Easy access for service and maintenance.
  • Full project assistance with hot water sizing and selection of equipment to match the application.
  • Extensive back up and support from our team of experienced engineers across the UK.
  • Long term commitment to spare parts.

Due to the Energy-related Products (ErP) Directive regulations we have a limited stock available of atmospheric water heaters. Talk to us today to secure your product or find out about availability.

Specification Units Dorchester DR-SA/SE Model
DR-SA 16 DR-SE 16 DR-SA 19 DR-SE 19
Water Continuous output with 44°C ΔT l/h 369 369 392 392
Continuous output with 50°C ΔT l/h 325 325 345 345
Continuous output with 55°C ΔT l/h 295 295 314 314
Storage capacity litres 278 278 372 372
Maximum operating water pressure (open vented) bar 8 8 8 8
Maximum operating water pressure (unvented) bar 3.5 (=cold feed pressure reducing valve preset in unvented kit
option)
Expansion relief valve setting (open vented kit) bar 5 5 5 5
Energy Building Regulations thermal efficiency gross % 76.54 76.54 76.54 76.54
Heating-up time, ΔT = 44°C min. 45 45 57 57
Heating-up time, ΔT = 50°C min. 51 51 65 65
Heating-up time, ΔT = 55°C min. 57 57 71 71
Standby losses kW/24h 11.3 11.3 n/a n/a
Gas Nat. Gas
G20-20mbar
Input power, gross-maximum kW 24.7 24.7 26.2 26.2
Output power-maximum kW 18.9 18.9 20.1 20.1
Gas inlet pressure-nominal mbar 20 20 20 20
Gas flow rate-maximum@1013.25 mbar and 15°C m3/h 2.4 2.4 2.5 2.5
LPG
G31-37mbar
Input power, gross/ (net)-maximum kW 22.5 22.5 24.5 24.5
Output-maximum kW 17.6 17.6 19.1 19.1
Gas inlet pressure-nominal mbar 37 37 37 37
Gas flow rate-maximum@1013.25 mbar and 15°C kg/h 1.6 1.6 1.8 1.8
Flue Approximate flue gas volume @15°C, 9.8% CO2,
N.T.P. (nat. Gas-G20)
m3/h 30.4 30.4 31.7 31.7
Flue gas temperature-maximum °C 275 275 275 275
Flue draught requirements mbar -0.125 -0.125 -0.125 -0.125
General Power consumption-DR-SA (DR-SE) W 30 (0*) 30 (0*) 30 (0*) 30 (0*)
Electrical supply DR-SA (DR-SE) Vac 230V 1Ph 50Hz (n/a*)
Weight when empty kg 117 122 144 149
Approximate shipping weight kg 122 127 149 154
Maximum floor load/weight filled with water kg 395 400 516 521
*Note: The basic DR-SE requires no power supply; 230V supply only required if any electrical options are to be used.
  Title Type Size  
Dorchester DR-SA and DR-SE water heater brochure Dorchester DR-SA and DR-SE water heater brochure Product brochures 2405 ko Download
Dorchester DR-SA/SE water heater dimensions Dorchester DR-SA/SE water heater dimensions Dimensions 90 ko Download
Dorchester DR-SA-SE water heater technical data table Dorchester DR-SA-SE water heater technical data table Data tables 59 ko Download
Dorchester DR-SA installation manual Dorchester DR-SA installation manual Installers guides 736 ko Download
Dorchester DR-SE he installation manual Dorchester DR-SE he installation manual Installers guides 1070 ko Download
Dorchester DR-SA 16 front view Dorchester DR-SA 16 front view CAD 18 ko Download
Dorchester DR-SA 16 plan view Dorchester DR-SA 16 plan view CAD 11 ko Download
Dorchester DR-SA 19 front view Dorchester DR-SA 19 front view CAD 18 ko Download
Dorchester DR-SA 19 plan view Dorchester DR-SA 19 plan view CAD 11 ko Download
Dorchester DR-SE 16 front view Dorchester DR-SE 16 front view CAD 17 ko Download
Dorchester DR-SE 16 plan Dorchester DR-SE 16 plan CAD 11 ko Download
Dorchester DR-SE 19 front view Dorchester DR-SE 19 front view CAD 17 ko Download
Dorchester DR-SE 19 plan view Dorchester DR-SE 19 plan view CAD 11 ko Download
Dorchester DR-SA water heater wiring diagram Dorchester DR-SA water heater wiring diagram Wiring diagrams 103 ko Download
Dorchester DR-SA seasonal efficiency sheet Dorchester DR-SA seasonal efficiency sheet Seasonal efficiency sheets 35 ko Download
Dorchester DR-SE seasonal efficiency sheet Dorchester DR-SE seasonal efficiency sheet Seasonal efficiency sheets 35 ko Download
  • Locations without electrical supply (DR-SE only).
  • Smaller commercial and public buildings including community schools, care homes, hotels, churches and retail units.
  • Unvented water supply kit - essential for any unvented application and includes an expansion vessel sized for the water heater and local pipework only.
  • Top to bottom pump recirculation pump kit to prevent stratification and protect against legionella within the water heater.
  • Electrical anode protection.
  • Flexible replacement anodes.
  • Time clock control kit (DR-SE only).
  • 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.