Flamco Flexfiller Direct G4 Pumpless Top-Up Pressurisation Unit 20100
The Flamco Flexfiller Direct G4 (order code 20100) is a silent, pumpless digital pressurisation unit for sealed heating and chilled-water systems in light-commercial and larger-domestic buildings. It connects directly to the incoming mains or boosted cold-water supply via the supplied flexible hoses, using available mains pressure to fill the system and maintain setpoint pressure — no booster pump required.
Mains feed-water passes through the unit's integrated Fluid Protection Category 3 (equivalent to Cat 4) backflow prevention, removing the need for a separate RPZ valve in many installations. A self-learning microprocessor controller with graphical display tracks expansion-vessel health, logs safety-valve activations, detects leaks and provides flood protection. MODBUS RTU and BACnet over RS485 come as standard for BMS integration, and the unit can be paired with the optional Flamconnect Remote service for cloud monitoring.
No booster pump means no motor noise, no pump wear and lower power draw — just 2 W on standby and around 19 W only while actively filling.
Integrated Fluid Protection Category 3 (equivalent to Cat 4) backflow prevention means no separate RPZ valve is required in most installations — saving cost and pipework complexity.
Onboard algorithms monitor expansion-vessel health, log safety-valve activations, detect leaks and trigger preventative-maintenance alarms before a failure occurs.
Both MODBUS RTU and BACnet over RS485 are included as standard — straightforward integration into the BMS without bolt-on protocol modules.
A runtime limiter stops the inlet solenoid if filling continues beyond a sensible window, plus an excessive-activation alarm for slow leaks, and a fully programmable volt-free common-alarm contact.
Two 400 mm flexible hoses with insulation are supplied — one for the mains inlet and one for the system outlet — speeding up installation in tight plant rooms.
| Manufacturer | Flamco (Aalberts hydronic flow control) |
| Model | Flexfiller Direct G4 |
| Order code (MPN) | 20100 |
| GTIN | 8712874201002 |
| Type | Pumpless digital top-up pressurisation unit |
| Approvals | WRAS & Kiwa; Fluid Protection Category 3 (equivalent to Cat 4) |
| Maximum top-up flow | 14 l/min (at 2 bar inlet) |
| Min. inlet (mains) pressure | 0.5 bar |
| Max. inlet (mains) pressure | 6.0 bar |
| Max. delivery pressure | 5.7 bar (mains pressure − 0.3 bar) |
| Max. system design pressure | 10 bar (PN10) |
| Max. system temperature at outlet | 90 °C |
| Max. inlet (cold-water) temperature | 45 °C |
| Ambient temperature range | 5 °C – 45 °C |
| System volume capacity | Up to 50,000 litres |
| Mains supply | 230 V (110 V available), 50 Hz |
| Stand-by power consumption | 2.0 W |
| Power consumption while filling | 19.4 W |
| Full-load current | 0.3 – 1.0 A (5 A fuse rating) |
| Protection class | IP44 (BS EN 60529) controller |
| Communication protocols | MODBUS RTU + BACnet via RS485 |
| Alarm contacts | 1 × programmable common alarm; 2 × N/C programmable |
| System & mains connections | 15 mm compression |
| Drain (tundish) connection | Universal: 22 mm comp / 32 mm PP push-fit / 32 mm PP solvent-weld |
| Hoses included | 2 × 400 mm flexible insulated hoses with isolation valves |
| Colour | Grey (RAL 7016) with red trim (RAL 3002) |
| Dimensions (H × W × D) | 359 × 262 × 141 mm (approx.) |
| Weight | 4 kg |
| Warranty | 2 years standard; up to 5 years with Flamco servicing |
Will it work on my system?
The Flexfiller Direct G4 needs the mains (or boosted) cold-water pressure to be at least 0.3 bar above the desired system fill pressure, within the 0.5–6.0 bar inlet range. For most UK domestic and light-commercial premises with a typical 2–4 bar mains supply this is comfortable — but on properties with low or fluctuating mains pressure, a pumped Flexfiller Mini or 280D may be needed instead.
Do I still need a separate RPZ valve?
In most cases no. The unit incorporates Fluid Protection Category 3 backflow prevention (equivalent to Category 4) certified by Kiwa — so a separate RPZ assembly is not normally required for a closed heating or chilled-water system. Always confirm with your local water authority and risk assessment.
Can it integrate with our BMS?
Yes. MODBUS RTU and BACnet over RS485 are included as standard, with alarm and status registers fully documented in the manual. A programmable volt-free common-alarm contact plus two additional N/C programmable contacts are provided for hardwired BMS or remote-dialler integration.
How big a system can it fill?
Rated for sealed systems up to 50,000 litres — larger domestic projects, schools, care homes, small offices and apartment blocks. Top-up flow at 14 l/min covers the typical leak-rate plus expansion-vessel make-up demand on systems of this scale.
How is it serviced?
An on-screen 12-month service reminder prompts annual maintenance; replacement parts are stocked individually. The 2-year standard warranty extends to up to 5 years when serviced by Flamco-trained engineers.
Original: $2,004.26
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Flamco Flexfiller Direct G4 Pumpless Top-Up Pressurisation Unit 20100
The Flamco Flexfiller Direct G4 (order code 20100) is a silent, pumpless digital pressurisation unit for sealed heating and chilled-water systems in light-commercial and larger-domestic buildings. It connects directly to the incoming mains or boosted cold-water supply via the supplied flexible hoses, using available mains pressure to fill the system and maintain setpoint pressure — no booster pump required.
Mains feed-water passes through the unit's integrated Fluid Protection Category 3 (equivalent to Cat 4) backflow prevention, removing the need for a separate RPZ valve in many installations. A self-learning microprocessor controller with graphical display tracks expansion-vessel health, logs safety-valve activations, detects leaks and provides flood protection. MODBUS RTU and BACnet over RS485 come as standard for BMS integration, and the unit can be paired with the optional Flamconnect Remote service for cloud monitoring.
No booster pump means no motor noise, no pump wear and lower power draw — just 2 W on standby and around 19 W only while actively filling.
Integrated Fluid Protection Category 3 (equivalent to Cat 4) backflow prevention means no separate RPZ valve is required in most installations — saving cost and pipework complexity.
Onboard algorithms monitor expansion-vessel health, log safety-valve activations, detect leaks and trigger preventative-maintenance alarms before a failure occurs.
Both MODBUS RTU and BACnet over RS485 are included as standard — straightforward integration into the BMS without bolt-on protocol modules.
A runtime limiter stops the inlet solenoid if filling continues beyond a sensible window, plus an excessive-activation alarm for slow leaks, and a fully programmable volt-free common-alarm contact.
Two 400 mm flexible hoses with insulation are supplied — one for the mains inlet and one for the system outlet — speeding up installation in tight plant rooms.
| Manufacturer | Flamco (Aalberts hydronic flow control) |
| Model | Flexfiller Direct G4 |
| Order code (MPN) | 20100 |
| GTIN | 8712874201002 |
| Type | Pumpless digital top-up pressurisation unit |
| Approvals | WRAS & Kiwa; Fluid Protection Category 3 (equivalent to Cat 4) |
| Maximum top-up flow | 14 l/min (at 2 bar inlet) |
| Min. inlet (mains) pressure | 0.5 bar |
| Max. inlet (mains) pressure | 6.0 bar |
| Max. delivery pressure | 5.7 bar (mains pressure − 0.3 bar) |
| Max. system design pressure | 10 bar (PN10) |
| Max. system temperature at outlet | 90 °C |
| Max. inlet (cold-water) temperature | 45 °C |
| Ambient temperature range | 5 °C – 45 °C |
| System volume capacity | Up to 50,000 litres |
| Mains supply | 230 V (110 V available), 50 Hz |
| Stand-by power consumption | 2.0 W |
| Power consumption while filling | 19.4 W |
| Full-load current | 0.3 – 1.0 A (5 A fuse rating) |
| Protection class | IP44 (BS EN 60529) controller |
| Communication protocols | MODBUS RTU + BACnet via RS485 |
| Alarm contacts | 1 × programmable common alarm; 2 × N/C programmable |
| System & mains connections | 15 mm compression |
| Drain (tundish) connection | Universal: 22 mm comp / 32 mm PP push-fit / 32 mm PP solvent-weld |
| Hoses included | 2 × 400 mm flexible insulated hoses with isolation valves |
| Colour | Grey (RAL 7016) with red trim (RAL 3002) |
| Dimensions (H × W × D) | 359 × 262 × 141 mm (approx.) |
| Weight | 4 kg |
| Warranty | 2 years standard; up to 5 years with Flamco servicing |
Will it work on my system?
The Flexfiller Direct G4 needs the mains (or boosted) cold-water pressure to be at least 0.3 bar above the desired system fill pressure, within the 0.5–6.0 bar inlet range. For most UK domestic and light-commercial premises with a typical 2–4 bar mains supply this is comfortable — but on properties with low or fluctuating mains pressure, a pumped Flexfiller Mini or 280D may be needed instead.
Do I still need a separate RPZ valve?
In most cases no. The unit incorporates Fluid Protection Category 3 backflow prevention (equivalent to Category 4) certified by Kiwa — so a separate RPZ assembly is not normally required for a closed heating or chilled-water system. Always confirm with your local water authority and risk assessment.
Can it integrate with our BMS?
Yes. MODBUS RTU and BACnet over RS485 are included as standard, with alarm and status registers fully documented in the manual. A programmable volt-free common-alarm contact plus two additional N/C programmable contacts are provided for hardwired BMS or remote-dialler integration.
How big a system can it fill?
Rated for sealed systems up to 50,000 litres — larger domestic projects, schools, care homes, small offices and apartment blocks. Top-up flow at 14 l/min covers the typical leak-rate plus expansion-vessel make-up demand on systems of this scale.
How is it serviced?
An on-screen 12-month service reminder prompts annual maintenance; replacement parts are stocked individually. The 2-year standard warranty extends to up to 5 years when serviced by Flamco-trained engineers.
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Description
The Flamco Flexfiller Direct G4 (order code 20100) is a silent, pumpless digital pressurisation unit for sealed heating and chilled-water systems in light-commercial and larger-domestic buildings. It connects directly to the incoming mains or boosted cold-water supply via the supplied flexible hoses, using available mains pressure to fill the system and maintain setpoint pressure — no booster pump required.
Mains feed-water passes through the unit's integrated Fluid Protection Category 3 (equivalent to Cat 4) backflow prevention, removing the need for a separate RPZ valve in many installations. A self-learning microprocessor controller with graphical display tracks expansion-vessel health, logs safety-valve activations, detects leaks and provides flood protection. MODBUS RTU and BACnet over RS485 come as standard for BMS integration, and the unit can be paired with the optional Flamconnect Remote service for cloud monitoring.
No booster pump means no motor noise, no pump wear and lower power draw — just 2 W on standby and around 19 W only while actively filling.
Integrated Fluid Protection Category 3 (equivalent to Cat 4) backflow prevention means no separate RPZ valve is required in most installations — saving cost and pipework complexity.
Onboard algorithms monitor expansion-vessel health, log safety-valve activations, detect leaks and trigger preventative-maintenance alarms before a failure occurs.
Both MODBUS RTU and BACnet over RS485 are included as standard — straightforward integration into the BMS without bolt-on protocol modules.
A runtime limiter stops the inlet solenoid if filling continues beyond a sensible window, plus an excessive-activation alarm for slow leaks, and a fully programmable volt-free common-alarm contact.
Two 400 mm flexible hoses with insulation are supplied — one for the mains inlet and one for the system outlet — speeding up installation in tight plant rooms.
| Manufacturer | Flamco (Aalberts hydronic flow control) |
| Model | Flexfiller Direct G4 |
| Order code (MPN) | 20100 |
| GTIN | 8712874201002 |
| Type | Pumpless digital top-up pressurisation unit |
| Approvals | WRAS & Kiwa; Fluid Protection Category 3 (equivalent to Cat 4) |
| Maximum top-up flow | 14 l/min (at 2 bar inlet) |
| Min. inlet (mains) pressure | 0.5 bar |
| Max. inlet (mains) pressure | 6.0 bar |
| Max. delivery pressure | 5.7 bar (mains pressure − 0.3 bar) |
| Max. system design pressure | 10 bar (PN10) |
| Max. system temperature at outlet | 90 °C |
| Max. inlet (cold-water) temperature | 45 °C |
| Ambient temperature range | 5 °C – 45 °C |
| System volume capacity | Up to 50,000 litres |
| Mains supply | 230 V (110 V available), 50 Hz |
| Stand-by power consumption | 2.0 W |
| Power consumption while filling | 19.4 W |
| Full-load current | 0.3 – 1.0 A (5 A fuse rating) |
| Protection class | IP44 (BS EN 60529) controller |
| Communication protocols | MODBUS RTU + BACnet via RS485 |
| Alarm contacts | 1 × programmable common alarm; 2 × N/C programmable |
| System & mains connections | 15 mm compression |
| Drain (tundish) connection | Universal: 22 mm comp / 32 mm PP push-fit / 32 mm PP solvent-weld |
| Hoses included | 2 × 400 mm flexible insulated hoses with isolation valves |
| Colour | Grey (RAL 7016) with red trim (RAL 3002) |
| Dimensions (H × W × D) | 359 × 262 × 141 mm (approx.) |
| Weight | 4 kg |
| Warranty | 2 years standard; up to 5 years with Flamco servicing |
Will it work on my system?
The Flexfiller Direct G4 needs the mains (or boosted) cold-water pressure to be at least 0.3 bar above the desired system fill pressure, within the 0.5–6.0 bar inlet range. For most UK domestic and light-commercial premises with a typical 2–4 bar mains supply this is comfortable — but on properties with low or fluctuating mains pressure, a pumped Flexfiller Mini or 280D may be needed instead.
Do I still need a separate RPZ valve?
In most cases no. The unit incorporates Fluid Protection Category 3 backflow prevention (equivalent to Category 4) certified by Kiwa — so a separate RPZ assembly is not normally required for a closed heating or chilled-water system. Always confirm with your local water authority and risk assessment.
Can it integrate with our BMS?
Yes. MODBUS RTU and BACnet over RS485 are included as standard, with alarm and status registers fully documented in the manual. A programmable volt-free common-alarm contact plus two additional N/C programmable contacts are provided for hardwired BMS or remote-dialler integration.
How big a system can it fill?
Rated for sealed systems up to 50,000 litres — larger domestic projects, schools, care homes, small offices and apartment blocks. Top-up flow at 14 l/min covers the typical leak-rate plus expansion-vessel make-up demand on systems of this scale.
How is it serviced?
An on-screen 12-month service reminder prompts annual maintenance; replacement parts are stocked individually. The 2-year standard warranty extends to up to 5 years when serviced by Flamco-trained engineers.
