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RM Stelflow Unvented Direct Slimline Solar

From £1,373.57 From £1,061.86

Electric & Solar Heated Hot Water Storage

  • 25 year guarantee on the vessel
  • 2 years guarantee on components
  • 50mm High-density insulation
  • Full unvented kit supplied, including remote expansion vessel
  • Treated to protect against corrosion

*Allow 7-10 working days delivery for this product

SKU: Stelflow Unvented Direct Slimline Solar Categories: ,


RM Stelflow Unvented Direct Slimline Solar Cylinder

Measuring just 475mm in diameter, the RM Stelflow Solar Direct Slimline gives those without any form of backup heating the opportunity to capitalise on the benefits of solar thermal technologies, by providing 2 immersion heaters to back the solar thermal up and provide pacification everyone has the ability to take advantage of the suns energy. As with all the Stelflow units the Solar Direct features the coil in coil high-efficiency heat exchangers.

RM Stelflow hot water cylinders have been constructed using high-quality components. A manufacturer guarantee of 25-year guarantee on the vessel and 2 years on parts, will give you a well-deserved peace of mind.

In the age of growing fuel bills, the RM Solar Direct presents a real option to help save homeowners money and reduce their carbon footprint thus safeguarding the future of the planet. Built to RM’s usual exacting standards the Solar Direct is a perfect off-gas product.



  • Working pressures Min: 1bar, Max: 3bar
  • 22mm compression fittings throughout
  • Minimum water supply 1.5bar, 20 Litres/min
  • 50mm insulation
  • New flat base for stability
  • 3kW Incoloy Immersion heater as standard
  • Clearly labelled unit connections
  • Butt welding for long life
  • 25-year guarantee on the vessel, 2 years on parts


Kit Included

Technical Specification


Product IH-RM025 IH-RM026 IH-RM027
Capacity 150L 180L 210L
Height (mm) 1430 1710 1920
Diameter (mm) 475 475 475
Weight Empty (kg) 47 53 55
Weight Full (kg) 193 228 261
Indirect Reheat (mins) 18 22 24
Immersion Reheat (mins) 108 130 151
Heat Exchanger (kW) 16.2 18.4 21
Solar Volume (L) 80 100 116
Standing Loss (kWh/day) 1.6 1.9 2.16
ErP Band C C C


Tapping Heights


Product IH-RM025 IH-RM026 IH-RM027
Cold Inlet 162 162 162
Bottom Coil 269 269 344
Stat Pocket 324 324 444
Immersion 1 309 309 384
Immersion 2 905 1082 1244
Secondary Return 1665
T&P Valve 1262 1527 1739



Additional information


150 Litre, 180 Litre, 210 Litre


RM Cylinders




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