Gledhill ES 120L Direct Unvented Cylinder: Complete Buyer’s Guide (2026)
Gledhill ES 120L Direct Unvented Cylinder:
If you’re looking for a reliable 120-litre electric unvented hot water cylinder, the Gledhill ES 120L Direct Unvented Cylinder (SESINPDR120) is one of the best value options available in the UK. Designed for smaller homes, flats, apartments and properties without a boiler-fed hot water system, it combines durable Duplex stainless steel construction with mains-pressure performance and efficient insulation.
Whether you’re replacing an ageing cylinder or installing a new hot water system, this guide explains everything you need to know before buying.
What Is the Gledhill ES 120L Direct Unvented Cylinder?
The Gledhill Stainless ES 120L Direct Unvented Cylinder, model SESINPDR120, is an electrically heated hot water cylinder designed to deliver reliable mains-pressure hot water throughout the home.
Unlike an indirect cylinder, the Direct model uses two integrated 3kW immersion heaters rather than a boiler heating coil. This makes it ideal for electric-only properties or homes where the hot water is heated independently from the central heating system.
Key Features
- 120-litre nominal capacity (approximately 118 litres actual capacity)
- Model: SESINPDR120
- Two 3kW immersion heaters
- Duplex stainless steel construction
- 40mm high-performance insulation
- Mains-pressure hot water
- Compact 530mm diameter
- Height: 832mm
- No cold water storage tank required
- Up to 25-year manufacturer warranty (subject to terms)
- WRAS, NSF and WRC approved design
Who Is the Gledhill ES 120L Suitable For?
The ES 120L Direct is an excellent choice for:
- One and two-bedroom houses
- Flats
- Apartments
- Holiday homes
- Annexes
- Electric-only properties
- Homes without a gas or oil boiler
- Small families with moderate hot water demand
The 120L capacity offers a useful increase over a 90L model while remaining compact enough to fit in many airing cupboards.
Why Choose an Unvented Cylinder?
An unvented cylinder connects directly to the incoming mains water supply instead of relying on a cold water storage tank.
Benefits include:
- Better shower pressure
- Faster bath filling
- Improved hot water flow
- More usable loft space
- No header tank
- Cleaner water supply
- Reduced maintenance
- Check out Gledhill ES web site
Actual performance depends on the incoming mains pressure and flow rate, so these should always be checked before installation.
Duplex Stainless Steel Construction
The Gledhill ES range uses a Duplex stainless steel inner cylinder, offering excellent strength and corrosion resistance.
Benefits include:
- Long service life
- Excellent corrosion protection
- High pressure capability
- Reduced maintenance
- Reliable long-term performance
Combined with Gledhill’s manufacturing expertise, this provides a durable hot water solution at a competitive price.
Efficient Electric Water Heating
The Direct model is fitted with two 3kW immersion heaters, allowing efficient electric heating of the stored water.
This makes it particularly suitable for:
- Economy 7 installations
- Electric-only homes
- Replacement electric cylinders
- Modern apartments
- Holiday properties
Energy Efficiency
The ES 120L incorporates 40mm factory-applied insulation that helps reduce standing heat loss and keeps water hotter for longer.
Benefits include:
- Lower heat loss
- Reduced energy consumption
- Improved hot water retention
- Better efficiency between heating cycles
The cylinder carries an ErP energy rating of C.
Technical Specification
| Specification | Details |
|---|---|
| Manufacturer | Gledhill |
| Model | SESINPDR120 |
| Capacity | 118 Litres |
| Cylinder Type | Direct Unvented |
| Heat Source | Two 3kW Immersion Heaters |
| Material | Duplex Stainless Steel |
| Height | 832mm |
| Diameter | 530mm |
| Maximum Inlet Pressure | 12 Bar |
| Working Pressure | 6 Bar |
| Pressure Reducing Valve | 3 Bar |
| Insulation | 40mm |
| Energy Rating | C |
What Comes in the Box?
The cylinder includes:
- Two 3kW immersion heaters
- Expansion vessel
- Temperature and pressure relief valve
- 3 Bar inlet control group
- Installation instructions
Installation Requirements
The ES 120L Direct should always be installed by a suitably qualified installer competent in unvented hot water systems.
Before installation, they should confirm:
- Mains pressure
- Flow rate
- Electrical supply
- Available installation space
- Discharge pipe routing
- Compliance with current Building Regulations
Direct vs Indirect – What’s the Difference?
Direct Cylinder
Uses electric immersion heaters.
Ideal for:
- Electric-only homes
- Flats
- Apartments
- Holiday properties
Indirect Cylinder
Uses a heating coil connected to a boiler.
Ideal for:
- Gas boiler systems
- Oil boiler systems
- Traditional central heating systems
Frequently Asked Questions
Is 120 litres enough?
For many one or two-bedroom homes and smaller families, yes. However, the correct size depends on the number of occupants and your hot water usage.
Does it include immersion heaters?
Yes.
The ES 120L Direct is supplied with two factory-fitted 3kW immersion heaters.
Does it need a loft tank?
No.
As an unvented cylinder it connects directly to the incoming mains water supply.
Does it improve shower pressure?
Yes, provided the property has suitable incoming mains water pressure and flow.
Can it be used with Economy 7?
Yes.
Many installations use off-peak electricity tariffs, subject to correct controls and installation.
Why Buy the Gledhill ES 120L from SNH Tradecentre?
When you purchase from SNH Tradecentre, you’ll benefit from:
- Competitive online pricing
- Fast Mainland England delivery
- Expert plumbing and heating advice
- Secure online ordering
- Dedicated customer support
- Trusted independent plumbing merchant since 1969
- Full Gledhill Stainless ES range available
- Technical information and installation resources
Whether you’re a homeowner or a professional installer, SNH Tradecentre provides a straightforward way to order genuine Gledhill products.
Final Verdict
The Gledhill ES 120L Direct Unvented Cylinder is an excellent option for homeowners looking for reliable electric hot water without relying on a boiler. Its Duplex stainless steel construction, two 3kW immersion heaters, compact dimensions and mains-pressure performance make it a dependable choice for modern homes. With a competitive price and strong manufacturer backing, it represents outstanding value in the unvented cylinder market.
Key Takeaways
- The Gledhill ES 120L Direct Unvented Cylinder offers reliable mains-pressure hot water for small homes, using two 3kW immersion heaters instead of a boiler.
- Its Duplex stainless steel construction ensures strength and corrosion resistance, providing a long service life with reduced maintenance.
- Suitable for electric-only properties and users with moderate hot water demand, it fits well in various types of dwellings, such as flats and holiday homes.
- Key features include a compact design, high-performance insulation, and up to a 25-year manufacturer warranty for peace of mind.
- Purchasing from SNH Tradecentre ensures competitive pricing and expert customer support for Gledhill products.
Table of contents
- Gledhill ES 120L Direct Unvented Cylinder:
- Technical Specification
- What Comes in the Box?
- Installation Requirements
- Direct vs Indirect – What’s the Difference?
- Frequently Asked Questions
- Is 120 litres enough?
- Does it include immersion heaters?
- Does it need a loft tank?
- Does it improve shower pressure?
- Can it be used with Economy 7?
- Why Buy the Gledhill ES 120L from SNH Tradecentre?