Tml TW1X00400R Kettle lt. 400 in AISI 316L stainless steel with a fixed coil heat exchanger with rigid insulation

2-in-1 Hybrid Heat Pump Storage Tank 414 Litres in AISI 316L Stainless Steel – TW1X00400R

The TWIN TW1X00400R is an integrated 2-in-1 heat pump system combining in a single vertical unit a 414-litre DHW boiler in AISI 316L stainless steel (1.4404) (upper tank) and a 74-litre inertial buffer in carbon steel (lower tank). This innovative solution by TML Industrie Loddo allows a complete DHW production and heating system powered by a heat pump, while optimising space and reducing installation costs compared to two separate tanks.

Technical Specifications – TW1X00400R

• DHW boiler (upper tank):
• Material: AISI 316L stainless steel (1.4404) – Pickling and passivation inside and out
• Max pressure / Max temperature: 6 bar / 95°C
• Actual DHW capacity: 414 litres
• Heat exchanger: 4.6 m² – Fixed double parallel spiral coil – max 10 bar / 95°C
• Cathodic protection: Replaceable magnesium anode
• Inertial buffer (lower tank):
• Material: Carbon steel S235Jr – Anti-rust coating
• Max pressure / Max temperature: 4 bar / 95°C
• Buffer capacity: 74 litres
• Total insulation: Rigid PU foam + PVC 50 mm (Fire class B3 DIN 4102) – non-removable
• ErP (DHW boiler): Class B – Heat loss: 78.0 W
• Dimensions: Ø 650 mm × Height 1760 mm
• Weight: 131 kg
• Electric heater connection: 1½" fitting (heater not included)
• Warranty: 5 years

Twin Technology – Two Tanks in One Body

The TWIN system elegantly addresses the need for both a high-efficiency DHW boiler and an inertial buffer for heating. The double parallel spiral coil maximises contact surface in the coldest zones of the tank, reducing heat pump start/stop cycles and improving the overall system COP. The lower inertial buffer is fed by the same heat pump, acting as a thermal flywheel for the low-temperature heating circuit (underfloor heating, fan coils, etc.), further reducing start/stop cycles and extending heat pump service life.

Why Choose the TWIN TW1X00400R?

Compared to installing a separate DHW boiler and buffer, the TWIN offers: space savings (one footprint instead of two), reduced installation costs (fewer hydraulic connections, faster installation), optimised heat pump operation through combined thermal storage, and unified management of DHW + heating from a single heat source.

Standards and Certifications

The TW1X00400R complies with: PED Directive 2014/68/EU (Art. 4 Par. 3), Italian D.M. 6 April 2004 N.174, ErP Directive 2009/125/EC.