OSO Delta GeoCoil DGC300 300L Heat Pump Cylinder
The OSO Delta GeoCoil DGC300 is a 300-litre ErP A-rated heat pump cylinder — the most energy-efficient unvented hot water cylinder OSO produces. Featuring their award-winning Vacuum Insulation Panels (VIP) and NANOPUR insulation, it saves approximately 400 kWh per year in heat loss compared to glass-wool insulated products — enough energy savings over its lifetime to offset the entire cost of the cylinder. Designed around a massive 3.1m² tube heat exchanger, the DGC300 extracts heat from pumps up to 18kW with exceptional efficiency, while the INCOTEC immersion heater provides electric backup and legionella protection at all times.
The OSO Delta GeoCoil DGC300 is among a very select group of cylinders to achieve an ErP "A" energy rating at 300 litres. This is made possible by the combination of Vacuum Insulation Panels and NANOPUR foam — reducing standing heat loss to just 1.18 kWh per day. The result: lower running costs and improved SAP/EPC scores.
OSO's unique Vacuum Insulation Panels (VIP) — an innovation that won the H&V News Product of the Year award — eliminate heat conduction through the insulation layer, achieving a standing heat loss of just 49W. This saves approximately 400 kWh per year vs glass-wool alternatives.
The large-surface tube heat exchanger (3.1m²) is specifically designed for heat pump operation, extracting heat efficiently from refrigerant at low primary temperatures — essential for maximising heat pump COP and overall system performance.
An ultra-grade INCOTEC 3kW immersion heater sits above the heating coil, providing electric backup when the heat pump cannot meet demand. It also enables regular legionella pasteurisation cycles at temperatures above 60°C, as required by health regulations.
The inner tank is fabricated using OSO's ULTRAWELD welding process, delivering superior corrosion resistance in all UK water hardness zones. Combined with the 1.3mm thick stainless steel construction, this underpins the 25-year tank warranty.
Ships with a Honeywell motorised valve, electronic dual cylinder thermostat, T&P relief valve (10 bar / 90–95°C), full G3 kit, adjustable expansion vessel (12–24L), and factory-fitted adjustable feet. Compatible with both S-plan and Y-plan systems.
The smooth-surface tube heat exchanger resists limescale adhesion, maintaining heat transfer efficiency over the long term without the maintenance burden of a corrugated coil — particularly important in hard water areas.
The DGC300's ErP A rating and low heat loss figures are specifically valued by housebuilders and developers aiming to meet Part L and SAP energy requirements. The cylinder is cited in OSO's SAP support documentation.
Fitted with two sensor pockets (6/8mm) for heat pump controller temperature probes, plus an adjustable digital thermostat (20–70°C, preset 60°C) — enabling precise integration with heat pump control systems from all major manufacturers.
This is an unvented hot water cylinder. Installation must be carried out by a G3 registered engineer (e.g. registered with CIPHE, APHC, or an equivalent Competent Persons Scheme). All work must comply with Building Regulation G3. The immersion heater must be controlled externally — consult the installation manual for wiring details.
| Specification | Value |
|---|---|
| Model / Product No. | DGC 300 — OSO 11009123 |
| Storage Volume | 279 litres (nominal 300L) |
| Diameter | 595 mm |
| Height | 1,750 mm |
| Weight Empty | 63 kg |
| Weight Full | 340 kg |
| Heat Exchanger Surface Area | 3.1 m² |
| Max Heat Pump Input | 18 kW |
| Immersion Heater | 3 kW INCOTEC / 1 × 240V |
| Thermostat Set Point | 60°C (adjustable 20–70°C) |
| Standing Heat Loss | 49W / 1.18 kWh per day (EN 12897) |
| ErP Energy Rating | A |
| T&P Relief Valve | 10 bar / 90–95°C |
| Sensor Pockets | 2 × 6/8mm |
| Expansion Vessel | 12–24L supplied |
| Appliance Feet | Adjustable 0–40mm, factory fitted |
| Tank Warranty | 25 years (stainless steel inner vessel) |
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OSO Delta GeoCoil DGC300 300L Heat Pump Cylinder
The OSO Delta GeoCoil DGC300 is a 300-litre ErP A-rated heat pump cylinder — the most energy-efficient unvented hot water cylinder OSO produces. Featuring their award-winning Vacuum Insulation Panels (VIP) and NANOPUR insulation, it saves approximately 400 kWh per year in heat loss compared to glass-wool insulated products — enough energy savings over its lifetime to offset the entire cost of the cylinder. Designed around a massive 3.1m² tube heat exchanger, the DGC300 extracts heat from pumps up to 18kW with exceptional efficiency, while the INCOTEC immersion heater provides electric backup and legionella protection at all times.
The OSO Delta GeoCoil DGC300 is among a very select group of cylinders to achieve an ErP "A" energy rating at 300 litres. This is made possible by the combination of Vacuum Insulation Panels and NANOPUR foam — reducing standing heat loss to just 1.18 kWh per day. The result: lower running costs and improved SAP/EPC scores.
OSO's unique Vacuum Insulation Panels (VIP) — an innovation that won the H&V News Product of the Year award — eliminate heat conduction through the insulation layer, achieving a standing heat loss of just 49W. This saves approximately 400 kWh per year vs glass-wool alternatives.
The large-surface tube heat exchanger (3.1m²) is specifically designed for heat pump operation, extracting heat efficiently from refrigerant at low primary temperatures — essential for maximising heat pump COP and overall system performance.
An ultra-grade INCOTEC 3kW immersion heater sits above the heating coil, providing electric backup when the heat pump cannot meet demand. It also enables regular legionella pasteurisation cycles at temperatures above 60°C, as required by health regulations.
The inner tank is fabricated using OSO's ULTRAWELD welding process, delivering superior corrosion resistance in all UK water hardness zones. Combined with the 1.3mm thick stainless steel construction, this underpins the 25-year tank warranty.
Ships with a Honeywell motorised valve, electronic dual cylinder thermostat, T&P relief valve (10 bar / 90–95°C), full G3 kit, adjustable expansion vessel (12–24L), and factory-fitted adjustable feet. Compatible with both S-plan and Y-plan systems.
The smooth-surface tube heat exchanger resists limescale adhesion, maintaining heat transfer efficiency over the long term without the maintenance burden of a corrugated coil — particularly important in hard water areas.
The DGC300's ErP A rating and low heat loss figures are specifically valued by housebuilders and developers aiming to meet Part L and SAP energy requirements. The cylinder is cited in OSO's SAP support documentation.
Fitted with two sensor pockets (6/8mm) for heat pump controller temperature probes, plus an adjustable digital thermostat (20–70°C, preset 60°C) — enabling precise integration with heat pump control systems from all major manufacturers.
This is an unvented hot water cylinder. Installation must be carried out by a G3 registered engineer (e.g. registered with CIPHE, APHC, or an equivalent Competent Persons Scheme). All work must comply with Building Regulation G3. The immersion heater must be controlled externally — consult the installation manual for wiring details.
| Specification | Value |
|---|---|
| Model / Product No. | DGC 300 — OSO 11009123 |
| Storage Volume | 279 litres (nominal 300L) |
| Diameter | 595 mm |
| Height | 1,750 mm |
| Weight Empty | 63 kg |
| Weight Full | 340 kg |
| Heat Exchanger Surface Area | 3.1 m² |
| Max Heat Pump Input | 18 kW |
| Immersion Heater | 3 kW INCOTEC / 1 × 240V |
| Thermostat Set Point | 60°C (adjustable 20–70°C) |
| Standing Heat Loss | 49W / 1.18 kWh per day (EN 12897) |
| ErP Energy Rating | A |
| T&P Relief Valve | 10 bar / 90–95°C |
| Sensor Pockets | 2 × 6/8mm |
| Expansion Vessel | 12–24L supplied |
| Appliance Feet | Adjustable 0–40mm, factory fitted |
| Tank Warranty | 25 years (stainless steel inner vessel) |
Product Information
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Description
The OSO Delta GeoCoil DGC300 is a 300-litre ErP A-rated heat pump cylinder — the most energy-efficient unvented hot water cylinder OSO produces. Featuring their award-winning Vacuum Insulation Panels (VIP) and NANOPUR insulation, it saves approximately 400 kWh per year in heat loss compared to glass-wool insulated products — enough energy savings over its lifetime to offset the entire cost of the cylinder. Designed around a massive 3.1m² tube heat exchanger, the DGC300 extracts heat from pumps up to 18kW with exceptional efficiency, while the INCOTEC immersion heater provides electric backup and legionella protection at all times.
The OSO Delta GeoCoil DGC300 is among a very select group of cylinders to achieve an ErP "A" energy rating at 300 litres. This is made possible by the combination of Vacuum Insulation Panels and NANOPUR foam — reducing standing heat loss to just 1.18 kWh per day. The result: lower running costs and improved SAP/EPC scores.
OSO's unique Vacuum Insulation Panels (VIP) — an innovation that won the H&V News Product of the Year award — eliminate heat conduction through the insulation layer, achieving a standing heat loss of just 49W. This saves approximately 400 kWh per year vs glass-wool alternatives.
The large-surface tube heat exchanger (3.1m²) is specifically designed for heat pump operation, extracting heat efficiently from refrigerant at low primary temperatures — essential for maximising heat pump COP and overall system performance.
An ultra-grade INCOTEC 3kW immersion heater sits above the heating coil, providing electric backup when the heat pump cannot meet demand. It also enables regular legionella pasteurisation cycles at temperatures above 60°C, as required by health regulations.
The inner tank is fabricated using OSO's ULTRAWELD welding process, delivering superior corrosion resistance in all UK water hardness zones. Combined with the 1.3mm thick stainless steel construction, this underpins the 25-year tank warranty.
Ships with a Honeywell motorised valve, electronic dual cylinder thermostat, T&P relief valve (10 bar / 90–95°C), full G3 kit, adjustable expansion vessel (12–24L), and factory-fitted adjustable feet. Compatible with both S-plan and Y-plan systems.
The smooth-surface tube heat exchanger resists limescale adhesion, maintaining heat transfer efficiency over the long term without the maintenance burden of a corrugated coil — particularly important in hard water areas.
The DGC300's ErP A rating and low heat loss figures are specifically valued by housebuilders and developers aiming to meet Part L and SAP energy requirements. The cylinder is cited in OSO's SAP support documentation.
Fitted with two sensor pockets (6/8mm) for heat pump controller temperature probes, plus an adjustable digital thermostat (20–70°C, preset 60°C) — enabling precise integration with heat pump control systems from all major manufacturers.
This is an unvented hot water cylinder. Installation must be carried out by a G3 registered engineer (e.g. registered with CIPHE, APHC, or an equivalent Competent Persons Scheme). All work must comply with Building Regulation G3. The immersion heater must be controlled externally — consult the installation manual for wiring details.
| Specification | Value |
|---|---|
| Model / Product No. | DGC 300 — OSO 11009123 |
| Storage Volume | 279 litres (nominal 300L) |
| Diameter | 595 mm |
| Height | 1,750 mm |
| Weight Empty | 63 kg |
| Weight Full | 340 kg |
| Heat Exchanger Surface Area | 3.1 m² |
| Max Heat Pump Input | 18 kW |
| Immersion Heater | 3 kW INCOTEC / 1 × 240V |
| Thermostat Set Point | 60°C (adjustable 20–70°C) |
| Standing Heat Loss | 49W / 1.18 kWh per day (EN 12897) |
| ErP Energy Rating | A |
| T&P Relief Valve | 10 bar / 90–95°C |
| Sensor Pockets | 2 × 6/8mm |
| Expansion Vessel | 12–24L supplied |
| Appliance Feet | Adjustable 0–40mm, factory fitted |
| Tank Warranty | 25 years (stainless steel inner vessel) |
