Double Panel Plus Radiators (Type 21)

Striking the perfect balance between performance and space-saving design, our Type 21 radiators - also known as double panel plus radiators - offer excellent heat output with a slightly slimmer profile than Type 22 models. These radiators feature two panels and a single convector fin, making them a great choice for rooms where you want more warmth without increasing the depth of the unit too much.

What is a Type 21 Radiator?

A Type 21 radiator has two panels - one on the front and one on the back - with a single set of convector fins sandwiched between. This gives it a higher BTU output than a Type 11, but with a shallower profile than a Type 22 radiator - which is ideal if you want a more discreet fit while still delivering powerful warmth.

Why Choose a Type 21 Radiator?

• Slimline profile with strong heat output
• Great for medium to large rooms
• Available in white, anthracite, and black finishes
• Compatible with standard UK central heating systems
• Efficient solution for hallways, bedrooms, lounges and kitchens

Not sure which panel type is right for you? Read our expert guide on radiator panel types to help you choose the best fit for your home.

Find Your Perfect Heat Output

Our Type 21 radiators come in a wide range of sizes to suit small, medium or large spaces. Use our free BTU radiator calculator to work out how much heat you need for your room, and find the right size for your layout.

Why Buy Type 21 Radiators from BestHeating?

• 10-year guarantees on many models
• Free UK delivery as standard
• High performance at an affordable price
• Trusted brands including Milano & Stelrad

Ready to upgrade your heating? Shop our full collection of central heating radiators and explore our full range of panel types, finishes and styles to suit every space.

Frequently asked questions – Type 21 Radiators

What is a Type 21 radiator?

A Type 21 radiator is a double panel radiator with a single convector fin between the panels. It delivers more heat than a single panel radiator while maintaining a slimmer profile than a Type 22 model.

How does a Type 21 radiator compare to a Type 22?

Type 21 radiators have two panels and one set of fins, whereas Type 22 radiators have two panels and two sets of fins. This means Type 22 models offer more heat output, but Type 21 radiators are slimmer, making them ideal for tighter spaces.

What are the benefits of a double panel plus radiator?

Type 21 radiators provide a balance of strong heat performance and a reduced depth, making them perfect for areas where space is limited, but a higher BTU output is needed.

Are Type 21 radiators compatible with standard UK heating systems?

Yes. All our Type 21 radiators are suitable for use with conventional and combi boiler central heating systems. They're easy to install and work with most valve types.

Do these radiators come in different colours?

Absolutely. Our Type 21 collection includes white and anthracite finishes to help you match your heating with your home’s décor.