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GAH DualStream Water Control Twin Coil TDCI Hot Water Cylinder - 300 Litre
GAH DualStream Water Control Twin Coil TDCI Hot Water Cylinder - 300 Litre

GAH DualStream Water Control Twin Coil TDCI Hot Water Cylinder - 300 Litre

Your Price: £2,900.27
Part Number:4327

Choose Options and Quantity

Unvented Cylinder Direct Range
Direct Range Options
TDD 200-125
TDD 240-150 [+£94.03]
TDD 240-150 [+£90.55]
TDD 300-210 [+£163.69]
TDD 300-300 [+£377.56]
TDD 500-300 [+£526.62]
TDD 500-500 [+£728.64]
Unvented Cylinder Indirect Range
Indirect Range Options
TDI 200-125
TDI 200-210 [+£94.03]
TDI 240-150 [+£90.55]
TDI 300-210 [+£163.69]
TDI 300-300 [+£377.56]
TDI 500-300 [+£526.62]
TDI 500-500 [+£728.64]



Feature 5

Bedrooms:5, Bathrooms:2, Shower Rooms:2
Untitled Document

Why choose a Dualstream system?

  • No cistern in the loft - no risk of water stagnation, Legionella and frost damage
  • Greater plumbing designs, uses less pipe-work, saving time and money
  • Wholesome water to all cold taps and balanced hot and cold water supplies
  • Dualstream utilises one of the slimmest and highest volume yielding unvented cylinders on the market
  • Will provide a substantial increase in water volume, to both hot and cold-water outlets, with-in the building
  • Will work at very low flow rates (9 l/mm) 1 Bar (min Water Board supply requirements)
  • Sized correctly the system will fill any number of baths simultaneously and ideal for multi-bathroom dwellings
  • True 'power shower' performance without the need of pumps
  • Overcomes problems associated with low mains pressure or inadequate flow rates
  • Efficient insulation, low power consumption. All unvented cylinders are insulated with high density CFC free insulation.
  • Can replace the need for high maintenance noisy break tanks and booster pump sets
  • Accumulators and cylinders can be linked together for greater demands, for the larger properties, small hotels and leisure and sports clubs
  • Indirect Models from 125 - 500 litres (heated from a boiler source)
  • Direct Models from 125 - 500 litres (heated from electric immersion)
  • Accumulator models from 100 - 500 litres
  • Twin coil cylinders available on request
  • Immersion heater upgrades available
  • Unvented stainless steel cylinders up to 300 litres with 25 year warranty
  • All electrical components are covered by 2 year warranty
  • Accumulators have longest industry warranty at 5 years

The Dualstream System

The Dualstream systems by GAH Heating Products have been developed as an advanced solution for domestic hot and cold water installations. A Dualstream system will increase the water volume and maintain the mains pressure to both the hot and cold supplies, even when more than one outlet is in use at the same time. Dualstream has been designed to function on the minimum standard for domestic water supply as provided by local water authorities - which is 1 Bar at 9 litres per minute. GAH offer full technical assistance and design service to enable the optimum Dualstream system to be configured to overcome situations where poor mains supply and pressure are considered a problem.

How the Dualstream system works

The system mainly comprises:- an unvented direct or indirect cylinder, an accumulator (cold water storage vessel), a combination valve and an expansion relief valve. The accumulator has an internal controlled butyl diaphragm, incoming cold water is stored within this diaphragm at mains pressure. The air space between the diaphragm and the accumulator case is pressurised, this balances the supply and maintains pressure to the unvented hot water cylinder and cold outlets. When hot and cold water outlets are turned on the stored water from the accumulator supplements water from the incoming main, this results in consistent pressure and flow to all taps, showers and baths even when outlets are used simultaneously. Pressure will be sustained for as long as the accumulator is holding suffficient volume of water.

TDD 200-125

The code number refers to the cylinder sizes TDD 200-125 (Model code TDD = Direct), 200 litre accumulator followed by 125 litre hot water cylinder.

Storage Capacity (litres)

inlet/outlet size (inches)

Coil Surface (m² )

Coil Rating (kW)

Reheat Time ( T=50° C)

Element Power

Max. temp.

Dimensions in mm

Weight full (kg)












150 min