Glow-worm provides a wide range of mains-fed unvented hot water cylinders that are designed to work with any UK boiler, not just the Glow-worm range, in open vented and sealed heating systems.

Each manufactured from high grade stainless steel, with laser welded seams and guaranteed against perforation of the steel shell for 25 years. All Glow-worm cylinders have excellent insulation that achieves heat loss as low as 1.7kWh and a high recover heating coil that reheats the cylinder in as little as 20 minutes.