The Ideal HP290 Single Zone Pre-Plumbed Cylinder with Integrated Buffer adds hydraulic volume to a single-zone system — protecting the heat pump from short-cycling where system water volume alone would be too low. Available across the widest capacity range in the HP290 lineup, from 180 L up to 300 L. Ships fully pre-plumbed and pre-wired with the HP290 control box, pumps, diverter valve, magnetic filter, G3 safety kit and 3 kW immersion.
Integrated Buffer
Hydraulics
HP290 heat pump compatibility only
This cylinder range is designed exclusively for the Ideal HP290 R290 heat pump — the control box, wiring and pre-plumbed hydraulics are matched to the HP290 platform and are not a generic fit for other manufacturers' heat pumps.
G3-qualified installer required
Every HP290 cylinder is unvented and includes a full G3 safety kit. UK Building Regulations require the DHW side to be commissioned by a G3-qualified installer. Failure to install and commission to Ideal's instructions may invalidate the warranty.
When to choose a buffer
A buffer tank is the simpler hydraulic-stability option for straightforward single-zone setups — protecting the heat pump from short-cycling where the system's own water volume is too low. It's a more compact solution than a low loss header for single-zone properties.
Choose your capacity
| Capacity |
Format |
Model code |
Best for |
| 180 L |
Standard |
IDEPLUHP180DUOPPSZ-D8.2 |
Single-zone systems needing hydraulic separation via buffer |
| 210 L |
Standard |
IDEPLUHP210DUOPPSZ-D8.2 |
Typical single-zone retrofit with buffer-stabilised flow |
| 250 L |
Standard |
IDEPLUHP250DUOPPSZ-D8.2 |
Larger single-zone households with higher DHW demand |
| 300 L |
Standard |
IDEPLUHP300DUOPPSZ-D8.2 |
Large households, single-zone, highest DHW demand |
Why choose the Single Zone Pre-Plumbed Cylinder with Integrated Buffer
Integrated buffer volume
Adds system water volume to protect the heat pump from short-cycling — particularly useful on smaller single-zone systems or where thermostatic radiator valves reduce circuit volume at part-load.
Widest capacity range in the HP290 lineup
Available from 180 L up to 300 L — the broadest choice of DHW capacity across the whole HP290 pre-plumbed cylinder range, suiting everything from modest to very high-demand households.
Fully pre-plumbed and pre-wired
Circulation pump(s), 3-port diverter valve, magnetic filter, G3 safety kit and the HP290 control box all factory-fitted and wired. The installer connects primary, DHW, cold feed and mains power — no on-site hydraulic assembly.
Industry-leading reheat times
Multi-coil heat exchanger design engineered for fast DHW recovery even at the lower flow temperatures typical of heat pump operation — Ideal specifically call out reheat performance as a differentiator for the HP290 cylinder range.
HP290 control box included
The control box consolidates all electrical components and provides the homeowner-facing interface — smart grid and solar PV compatible, with Wi-Fi connectivity and Anti-Legionella scheduling built in.
G3 unvented safety kit as standard
Every cylinder includes the pressure/temperature relief valve, expansion vessel and discharge pipework needed to meet Part G3 of the Building Regulations for unvented hot water storage.
3 kW immersion heater
Every HP290 cylinder is fitted with a 3 kW immersion as standard — backup DHW heating and Anti-Legionella disinfection support alongside the heat pump.
Specification (all capacities)
| Range |
Ideal HP290 Pre-Plumbed DHW Cylinder — Single Zone Pre-Plumbed Cylinder with Integrated Buffer |
| Available capacities |
180 L / 210 L / 250 L / 300 L (all Standard) |
| Compatible heat pump |
Ideal HP290 R290 monobloc (exclusive fit) |
| Tank construction |
Duplex stainless steel |
| DHW type |
Unvented — full G3 safety kit included |
| Backup heater |
3 kW immersion (fitted as standard) |
| Control box |
HP290 Control Box (included) — smart grid and solar PV compatible |
| Anti-Legionella |
Weekly disinfect cycle to 60°C for 15 minutes (default), heat pump + immersion |
| Minimum system water flow rate |
At least 30 litres/minute recommended into the property |
| Optimum inlet pressure |
3 bar dynamic (will function at lower pressure with reduced performance) |
| Primary system minimum volume (HP290 platform) |
40 litres free system volume |
| Compatible controllers |
Ideal HP290 Controller or Ideal Halo Lite RF programmable room thermostat |
| Warranty |
Ideal HP290 platform warranty — up to 5 years parts and labour when registered within 30 days and serviced annually |
What's in the box (every capacity)
- Ideal HP290 pre-plumbed DHW cylinder — Single Zone Pre-Plumbed Cylinder with Integrated Buffer (capacity per selected variant)
- HP290 Control Box — pre-wired
- Circulation pump(s) — pre-plumbed
- 3-port diverter valve — pre-plumbed
- Magnetic system filter — pre-fitted
- Full G3 unvented safety kit (expansion vessel, T&P relief valve, discharge pipework components)
- 3 kW immersion heater — pre-fitted
- Manufacturer installation and maintenance documentation
What you'll also need (sold separately)
- Ideal HP290 R290 monobloc heat pump (matched capacity — see our HP290 heat pump listings)
- Ideal Halo Lite RF programmable room thermostat, or use the HP290 Controller as room thermostat
- Discharge pipework to a suitable tundish and drain point per G3 requirements
- Anti-freeze protection on any pipework exposed to ambient temperatures below 5°C
- System inhibitor dosing per BS 7593:2019
Frequently Asked Questions
Which capacity should I choose?
As a rule of thumb: 180 L for 1–2 bathroom homes with moderate demand, 210 L for typical 2 bathroom households, 250 L for 3 bathroom homes, and 300 L for 4+ bathrooms or very high DHW demand. This configuration offers the widest capacity choice in the HP290 range.
Why choose buffer over low loss header for a single zone?
For a single heating zone, a buffer tank gives sufficient hydraulic stability without the added complexity of a low loss header — which is more commonly specified on multi-zone systems with variable flow rates. Your installer's system design will confirm which is appropriate.
Do I need a G3-qualified installer?
Yes — every HP290 cylinder is an unvented hot water cylinder. UK Building Regulations require the DHW side to be commissioned by a G3-qualified installer. Failing to install and commission to Ideal's manufacturer instructions may invalidate the warranty.
What's included in the control box?
The HP290 Control Box consolidates the electrical components for the whole system and gives the homeowner-facing interface for heating and DHW schedules, Anti-Legionella cycling, and Wi-Fi connectivity. It's smart grid and solar PV compatible as standard, and is included in every pre-plumbed cylinder.
Is a room thermostat included?
The HP290 Controller can itself function as a room thermostat if no separate programmable room thermostat is fitted. For a dedicated wireless room thermostat experience, Ideal's Halo Lite RF is the compatible option — sold separately.
Can this cylinder be used with a different heat pump?
No — the HP290 pre-plumbed cylinder range is designed exclusively for the Ideal HP290 R290 heat pump. The control box, wiring and pre-plumbed hydraulics are matched specifically to that platform and are not a generic unvented cylinder for other manufacturers' systems.
