Autofill® Pressurisation Unit

From £1,330.00 £1,596.00 inc. vat


Autofill is a new type of pressurisation unit for filling “non-house” heating or chilled water systems. Filling loops with a Double Check Valve must no longer be used for non-house primary circuits – see Water Regulations. Autofill replaces traditional pressurisation units and requires no tank or pump (except model AFP, which has a booster pump for tall buildings without boosted cold water). Autofill is exceptionally compact at just 300 mm square. The unit complies with the new Water Regulations for both filling and pressurising the primary system. The primary components consist of a Fluid Category 4 backflow prevention device, internal mechanical quick-fill valve, top-up pressure controlling equipment, high & low cut-out switches with BMS output, inlet and outlet (system) pressure gauges. The unit is supplied fully assembled and tested. Inlet and outlet stainless steel braided hoses with servicing valves and push fit connections are provided to facilitate installation.


Primary Heating Systems; Under Floor Heating; Refrigerating Equipment; Chilled Water Circuits; Cooling Circuits; Industrial Processes

Product Specification
  • Powered Yes
  • Requires Annual Testing Yes
Specification Clause

The primary sealed heating system shall be filled and pressurised by an Autofill pressurisation unit – model AFS22 – with high and low pressure fault lamps – as manufactured and commissioned by Arrow Valves Ltd – Tel 01442 823123 . The unit shall incorporate a manual quick fill / flushing valve and a pressure reducing valve, which allows the system to be filled without electrical power with Fluid Category 4 protection – an external quick fill facility is not required. The quick fill rate shall be 1800 litres per hour @ 1 bar pressure differential.
The automatic filling device is to be connected to the mains or, where the mains supply pressure is insufficient for the static head required, the unit shall be supplied from the boosted cold water service if available. The manufacturer’s flexible hoses incorporating a servicing valve shall be used. A double check valve is not required.
Automatic filling shall be via a solenoid valve and pressure switch. The cold fill switch-on pressure shall be 0.2 bar more than the static head of the system. The unit shall incorporate lamps to indicate filling and standby conditions.
The base of the cabinet must be 300 – 1500 mm above the floor and adequate access shall be provided for testing.
The outlet from the unit must be connected to the primary circuit return before the circulation pump. A DN32 discharge pipe must be connected to the integral tundish and taken to a gully. The unit must be commissioned prior to use by the manufacturer in accordance with the Water Regulations and a commissioning certificate provided.

Data Sheets


autofilldatasheet-1.pdf (902.15 KB)


Installation Guide

autofillommanual.pdf (798.52 KB)


Additional Information



Approval Certificate

1812353-AFS.pdf (829.63 KB)