The Worcester Bosch Greenstar 32CDi Compact is a 32kW gas combi for homes that need more hot water than a standard one-bathroom combi gives, but don’t have much space. It delivers around 11.5 litres of hot water a minute at a 40°C rise, and at 280mm deep it still fits in a standard kitchen cupboard.
It’s the middle model in Worcester’s CDi Compact range and is still available from UK merchants in 2026, in natural gas and LPG versions. Below, we look at who it suits, what it costs to install and how it compares with the newer Greenstar 4000 and Greenstar 8000+.
What Are The Worcester Bosch 32CDi Compact’s Key Specs?
It’s a 32kW gas combi with a 24kW heating output, 11.5 l/min of hot water at a 40°C rise and an A rating for heating and hot water.
| Specification | Greenstar 32CDi Compact |
| Boiler type | Wall-hung gas condensing combi |
| Hot water output | 32kW |
| Central heating output | 24kW |
| Hot water flow rate | 11.5 l/min at 40°C rise (about 13.1 l/min at 35°C rise) |
| ErP rating | A for heating, A for hot water |
| Dimensions (H x W x D) | 690 x 390 x 280mm |
| Fuel | Natural gas or LPG (separate LPG model) |
| Controls | Bosch EasyControl compatible, works with most smart thermostats |
| Status | Still available in 2026; newer alternatives are the Greenstar 4000 and Greenstar 8000+ |
What Is The Worcester Bosch Greenstar 32CDi Compact?
It’s the middle model in Worcester’s CDi Compact range, which packs a lot of hot water into a small casing.
There are three models, the 28CDi, 32CDi and 36CDi, and they all measure 690 x 390 x 280mm. That makes them some of the most cupboard-friendly combis Worcester has made.
Its 32kW hot water output gives noticeably stronger showers than the 28CDi, while the heating output stays at 24kW. In practice, it isn’t a bigger heating boiler. It’s a better hot water boiler.
That suits homes where hot water demand is higher than the radiator load would suggest. Think of a three bedroom house where the family showers back to back every morning.
If you already own a 32CDi Compact, it’s a well-supported Worcester model that Gas Safe engineers see every week. Parts are easy to source, but once yours is over 8 years old, replacing it is usually better value than paying for repairs.
What Features Does The 32CDi Compact Have?
Its headline feature is roughly 15% more hot water than the 28CDi from the same cupboard-sized casing.
- Kitchen cupboard fit. At 280mm deep it slots into a standard wall unit, which frees up space and keeps the kitchen tidy.
- Higher hot water output. The 32kW hot water side gives roughly 15% more flow than the 28CDi.
- Hot water pre-heat. This keeps the hot water side warm so you wait less at the tap, and you can turn it off if you’d rather save the gas.
- Smart compatible. It works with Bosch EasyControl and most third-party smart thermostats. Our smart thermostats page covers the options.
- Solar compatible. It can take pre-heated water from a solar thermal system.
- LPG version. There’s a dedicated LPG model for off-gas homes.
How Efficient Is The Worcester 32CDi Compact?
It’s ErP A-rated for both heating and hot water, and with a connected Bosch EasyControl thermostat the heating package rating can rise to A+.
The rating on the box only tells part of the story, though.
A condensing boiler saves the most gas at lower flow temperatures, so ask your installer to set the heating flow around 55 to 60°C if your radiators allow. Weather or load compensation helps the boiler modulate instead of cycling on and off, and a magnetic filter keeps sludge away from the heat exchanger.
Because the heating output is the same 24kW as the 28CDi, picking the 32CDi won’t raise your heating costs. You only use the extra power when you’re drawing hot water.
What Are The Pros And Cons Of The 32CDi Compact?
Its main plus is stronger hot water than the 28CDi in the same casing, and its main minus is that it can’t run two showers at full flow.
Pros
- Stronger hot water than the 28CDi with no increase in size
- Fits a standard kitchen cupboard
- Natural gas and LPG versions
- Works with EasyControl and popular smart thermostats
- Widely known by engineers, with good parts availability
Cons
- Still not enough for two showers running at full flow
- Older design and simpler display than the Greenstar 4000 and 8000+
- Costs more than the 28CDi and many rival brands
- The extra hot water output is wasted if your mains flow rate is low
What Size Home Does The 32CDi Compact Suit?
It’s a good match for two to three bedroom homes with one main bathroom, perhaps with an extra shower room or en-suite that gets used now and then. It handles up to around 12 radiators comfortably, as long as the home is reasonably insulated.
Your mains water supply is the key check.
To get 11.5 l/min at a 40°C rise, your incoming cold supply has to deliver that flow. Your engineer should test it at the kitchen tap before you choose between the 28CDi Compact, the 32CDi and the 36CDi Compact. Our guide on how to size a combi boiler covers the details.
With two full bathrooms in regular use at the same time, a combi may not be the right answer. A system boiler with a cylinder could serve you better. Our guide to combi, system and conventional boilers explains the difference.
How Much Does It Cost To Install A Worcester 32CDi Compact In 2026?
Expect around £2,400 to £3,100 for a like-for-like combi swap, rising to £3,300 to £4,600 if you’re converting from a system or regular boiler.
Installation costs depend more on your home than on the boiler. Relocating the boiler or converting from a tank-fed system adds labour, pipework and sometimes a new flue.
| Type of job | Typical installed price (guide only) |
| Combi to combi swap, same location | £2,400 to £3,100 |
| Combi swap with relocation or new flue | £2,900 to £3,700 |
| System or regular boiler to combi conversion | £3,300 to £4,600 |
These guide prices include VAT, a magnetic filter, a system flush and standard controls. The final figure will depend on access, the flue route, the state of your existing pipework and the controls you pick. Our guide to how much a new boiler costs has a fuller breakdown.
What Are The Best Alternatives To The 32CDi Compact?
The Greenstar 4000 30kW is the newer like-for-like option, while the 36CDi Compact, the Greenstar 8000+ and Vaillant’s 30 to 32kW combis give you more choice.
- Worcester Bosch Greenstar 4000 30kW. Worcester’s newer mid-range combi has a colour display and a Quick Tap water-saving mode, and gives about 12.3 l/min at a 35°C rise. Read our Greenstar 4000 30kW review.
- Worcester Bosch Greenstar 36CDi Compact. The same casing with even more hot water, around 12.9 l/min at a 40°C rise.
- Worcester Bosch Greenstar 8000+ 32kW. The premium Worcester combi, with a touchscreen, a 29.6kW heating output and 12 l/min at a 40°C rise. It’s larger, so check your space first.
- Vaillant 30kW to 32kW combis. Strong rivals at a similar output. See our Vaillant 32kW combi review.
Is The Worcester Bosch 32CDi Compact Worth It?
Yes, if you want better showers than a 28kW combi can give but have no room for a larger boiler.
As long as your mains supply can keep up, it’s a dependable, space-saving choice from a brand engineers trust.
Choose it if
- Your boiler has to fit inside a kitchen cupboard
- You have one bathroom plus an occasional second shower
- Your mains flow rate is good enough to use the extra output
Look elsewhere if
- You regularly run two showers at the same time
- You want the newest Worcester features and display
- Your water pressure is low, in which case a smaller combi will perform just as well
Get A Free Boiler Quote From Clever Energy Boilers
Clever Energy Boilers installs Worcester Bosch combis for homeowners and landlords across the North West, Yorkshire and the Midlands.
As Worcester Bosch accredited installers, we size each boiler to your home. We check your radiators, hot water demand and mains flow before we recommend a model.
Our Worcester Bosch boiler installations come with the option of long, market-leading warranties through Clever Energy, and you can spread the cost with boiler finance.
Use our online boiler quote tool to get a fixed price in a few minutes, with no obligation.
Frequently Asked Questions
Is The Worcester Bosch 32CDi Compact Still Available?
Yes, it’s still sold through UK merchants and installers in 2026. Worcester’s newer Greenstar 4000 and 8000+ ranges are also available if you’d prefer a more recent design.
What’s The Difference Between The 28CDi And 32CDi Compact?
The 32CDi gives more hot water, around 11.5 l/min at a 40°C rise against 10 l/min for the 28CDi. Both have a 24kW heating output and the same casing size.
How Many Radiators Can The 32CDi Compact Run?
Up to around 12 radiators in most homes. The heating output is 24kW, so a heat loss check will confirm it suits yours.
Can The 32CDi Compact Run Two Showers At Once?
Not at full flow. It can manage a shower and a tap at the same time, but two showers together will lose flow and temperature at both.
Does The 32CDi Compact Need An Annual Service?
Yes, an annual service by a Gas Safe engineer keeps it safe and efficient, and helps protect any warranty you take out through Clever Energy. Our Clever Care servicing plans cover this.