Vaillant · Heat-pump or fixed-AC model
uniSTOR heat pump cylinder
Vaillant uniSTOR heat-pump cylinders provide separate domestic-hot-water storage in 150 to 800 litre classes.
Specifications
| Specification | Value |
|---|---|
| Type | indirect domestic-hot-water cylinder for heat-pump systems |
| Cylinder capacity (litres) | 150, 200, 250, 300, 500 and 800 manufacturer classes |
| Product codes | VIH RW GB families; exact suffix identifies size and pre-plumbed or standard form |
| Pre plumbed sizes l | 150, 200, 250 and 300 |
| Standard sizes l | 150, 200, 250, 300, 500 and 800 across domestic and large-capacity forms |
| Tank material | stainless steel |
| Compatibility | Vaillant heat pumps, subject to the system design and exact cylinder code |
| Warranty (years) | check the cylinder terms; a separate current uniSTOR page states 25-year anti-corrosion cover for the stainless-steel tank |
uniSTOR is Vaillant’s separate domestic-hot-water cylinder range for heat-pump systems. It provides storage and heat-exchanger surface area; it does not determine the outdoor heat pump’s space-heating output.
Six storage classes
The current UK heat-pump range lists 150, 200, 250, 300, 500 and 800 litre classes. Pre-plumbed products cover 200, 250 and 300 litres, with a separate 150 litre slimline pre-plumbed form. Standard products cover 150 to 300 litres, while larger 500 and 800 litre vessels use their own technical schedule.
Codes begin VIH RW GB, followed by size and configuration details. Nominal names and actual usable storage can differ, so the exact datasheet is needed for a hot-water calculation.
Cylinder sizing is separate from heat loss
The cylinder is selected from occupancy, draw-off pattern, outlet temperatures and reheat requirement. The heat pump is selected from the building heat loss and its output at design conditions. A larger outdoor unit does not by itself make a smaller cylinder suitable.
Coil area, primary flow rate, immersion heater and standing loss vary across the range. The 500 and 800 litre brochure, for example, has a different electrical and hydraulic schedule from domestic 150 to 300 litre units.
Compatibility and cover
Vaillant describes uniSTOR as compatible with its heat-pump range, but the design still needs the exact system schematic, sensors and controls. aroTHERM plus can instead use uniTOWER where its integrated 188 litre storage and hydraulic arrangement fit the project.
A separate current uniSTOR page states a 25-year anti-corrosion guarantee for the stainless-steel tank. That wording is component-specific rather than a 25-year guarantee for controls, immersion heaters or the connected heat pump. The cylinder certificate and terms should identify the applicable cover.
Related entries
Manufacturer and reference sources
Brand
Reference type
Heat-pump or fixed-AC model
Last reviewed
23 Jul 2026
Current status
Current in the manufacturer's UK range.