
The Story
The JAB DUC 2 Indirect Hi-Flo is a high-recovery unvented stainless-steel hot water storage cylinder built for households and light commercial premises with heavy simultaneous hot water demand. Heated indirectly from a boiler coil and backed up by twin 3kW immersion heaters, it combines a duplex stainless-steel shell with a factory-fitted safety group and a remote-mounted expansion vessel, and is manufactured in Britain.
The remote expansion vessel ships with its own wall-mounting bracket, and the full unvented installation kit is included, so the only additions on site are pipework, insulation lagging where required, and the structural connections listed below.
| Capacity & Construction | |
| Nominal Capacity | 250L |
| Cylinder Type | Indirect, unvented, duplex stainless-steel |
| Grade | 316L stainless-steel body |
| Manufacture | Made in Britain |
| Energy Rating (ErP) | C |
| Dimensions | |
| Overall Height | 1500mm |
| Overall Diameter | 580mm |
| A – Immersion Height | 195mm |
| B – Thermostat Pocket Height | 225mm |
| C – Boiler Flow Height | 555mm |
| D – Secondary Return Height | 975mm |
| E – Hot Water Draw-Off Height | 1140mm |
| Performance | |
| Coil Output | 28kW |
| Reheat Time (from cold) | 35 min |
| Reheat Time (75% draw-off, with boiler) | 25 min |
| 24-Hour Standing Heat Loss | 2.69 kWh / 24hrs |
| Connections & Safety | |
| Hot Water Draw-Off | 28mm |
| Secondary Return | 28mm |
| Boiler Flow | 28mm |
| Boiler Return | 28mm |
| Cold Feed | 28mm |
| Inlet Valve Group | 1″ hot and cold, 28mm inlet control valve |
| Temperature & Pressure Relief Valve | 1/2″, factory-set 7 bar / 90°C |
| Immersion Heater(s) | 2 x 3kW single phase |
| Expansion Vessel | Remote-mounted, wall bracket supplied |
| Unvented Kit | Full kit supplied |

Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Description
The JAB DUC 2 Indirect Hi-Flo is a high-recovery unvented stainless-steel hot water storage cylinder built for households and light commercial premises with heavy simultaneous hot water demand. Heated indirectly from a boiler coil and backed up by twin 3kW immersion heaters, it combines a duplex stainless-steel shell with a factory-fitted safety group and a remote-mounted expansion vessel, and is manufactured in Britain.
The remote expansion vessel ships with its own wall-mounting bracket, and the full unvented installation kit is included, so the only additions on site are pipework, insulation lagging where required, and the structural connections listed below.
| Capacity & Construction | |
| Nominal Capacity | 250L |
| Cylinder Type | Indirect, unvented, duplex stainless-steel |
| Grade | 316L stainless-steel body |
| Manufacture | Made in Britain |
| Energy Rating (ErP) | C |
| Dimensions | |
| Overall Height | 1500mm |
| Overall Diameter | 580mm |
| A – Immersion Height | 195mm |
| B – Thermostat Pocket Height | 225mm |
| C – Boiler Flow Height | 555mm |
| D – Secondary Return Height | 975mm |
| E – Hot Water Draw-Off Height | 1140mm |
| Performance | |
| Coil Output | 28kW |
| Reheat Time (from cold) | 35 min |
| Reheat Time (75% draw-off, with boiler) | 25 min |
| 24-Hour Standing Heat Loss | 2.69 kWh / 24hrs |
| Connections & Safety | |
| Hot Water Draw-Off | 28mm |
| Secondary Return | 28mm |
| Boiler Flow | 28mm |
| Boiler Return | 28mm |
| Cold Feed | 28mm |
| Inlet Valve Group | 1″ hot and cold, 28mm inlet control valve |
| Temperature & Pressure Relief Valve | 1/2″, factory-set 7 bar / 90°C |
| Immersion Heater(s) | 2 x 3kW single phase |
| Expansion Vessel | Remote-mounted, wall bracket supplied |
| Unvented Kit | Full kit supplied |





















