Cast Iron Radiators

Buying guide

Cast iron radiators heat up steadily and keep giving out warmth after the boiler switches off, and they look right in a period house and a modern one alike. Choosing one is a matter of three decisions: the design, the height and depth that fit the wall, and the number of sections for the heat the room needs.

Why choose a cast iron radiator?

• Steady, lasting heat. Cast iron holds a lot of heat, so it warms up gently and keeps radiating after the heating goes off.
• Period character. Many Carron designs are based on originals from the 1880s to the 1930s, from French Rococo to American column radiators.
• Made to order. Each radiator is hand assembled to the number of sections you choose, then finished to order.
• Built to last. Carron gives its cast iron radiators a lifetime guarantee.
• Dual fuel option. Every design can take a Carron electric heating element.

The designs, by column

The number of columns is how many tubes make up each section from front to back. More columns mean a deeper radiator and more heat per section.

Plain and classic

Victorian column

The classic column radiator, first made in America in the 1880s, in 2, 3, 4, 6 and 9 column versions. Looks as good in a modern room as a period one.

See the Victorian 4 Column

Decorative

Rococo and Daisy

French designs of the 1890s with scalloped tops, interwoven decoration and flowing daisy patterns, for a statement piece.

Shop decorative radiators

Contemporary

Rathmell

Curved tops, crisp lines and arched feet: a modern take on the column radiator in 2, 4, 6 and 9 columns.

See the Rathmell 4 Column

Slim for hallways

Narrow Eton and Victorian 2 Column

Only 80mm and 70mm deep, for hallways and tight spots where a deeper radiator would be in the way.

See the Narrow Eton

Height and depth

Start with the wall. Under a window, the radiator should sit below the sill; on a plain wall you have more freedom. Then check how far it can stand out into the room.

• Low windows and bays: the low level models, from 325mm (Victorian 4 Column) to 340mm (Rathmell 9 Column), which stand on their own feet.
• Hallways and narrow rooms: the shallowest designs, the 70mm deep Victorian 2 Column, the 80mm Narrow Eton, the 81mm Rathmell 2 Column and the 115mm Rococo 1 Column.
• Large rooms: deeper, taller sections give more heat in less length: the Churchill at 975mm gives 173W per section, the Ribbon 4 Column at 810mm 170W and the Victorian 6 Column at 920mm 164W.

Every listing gives the height, depth, section width, vertical pipe centres and weight for each size.

How many sections do you need?

Work out the heat the room needs, then divide by the output per section.

1. Heat needed. As a rough guide, allow about 1kW (1,000W) for every 14 cubic metres of room. A 4m x 4m room with a 2.4m ceiling is 38 cubic metres, so about 2,700W. Older, draughty or high-ceilinged rooms need more, and a heat loss check by your heating engineer gives the right answer.
2. Split it between radiators if the room will have more than one.
3. Divide by the output per section. A Victorian 4 Column at 660mm gives 77W per section at ΔT50, so 1,350W needs about 18 sections.
4. Check the length. Multiply the section width by the number of sections. The Victorian 4 Column's sections are about 61mm wide, so 18 sections are roughly 1,100mm long before the end fittings.

Our radiators are assembled in 6 to 20 sections. If you need more heat than 20 sections give, use two radiators or a deeper, higher output design.

What ΔT50 means, and heat pumps

Radiator outputs are quoted at ΔT50 (delta T 50): the average water temperature is 50°C above room temperature, for example 70°C water in a 20°C room. That is typical of a traditional gas boiler system. A system running cooler water, such as a heat pump, gets less heat from the same radiator. At ΔT30, for example, Carron rates its Bassingham towel rail at roughly half its ΔT50 output, and radiators fall in a similar way. If you have or plan a heat pump, ask your engineer to size every radiator at your system's actual temperature, which usually means more sections or deeper designs.

Where to put a radiator

Under a window is the traditional spot, because the rising warm air counters the cold coming off the glass; choose a height that sits below the sill. On a long wall, a longer radiator spreads heat more evenly than a short tall one. Leave space around the radiator for air to circulate: furniture pushed hard against it, or heavy curtains over it, cut the heat that reaches the room. In a large room, two radiators on different walls usually heat more evenly than one big one.

Choosing a style for your home

Match the radiator to the house where you can. Victorian and Edwardian houses suit the Victorian column, the Princess and the decorative Rococo, Daisy, Orleans and Verona. Art Nouveau rooms suit the Liberty and Dragonfly. A 1930s house suits the Deco. For a modern room, the plain Victorian column in a bold colour, or the Rathmell with its crisp lines, sits comfortably. The Churchill, based on an 1880s design first used in government buildings, gives a bold, deep section for large rooms. If you are also choosing a fireplace, see our period fireplaces.

Finishes

• Primer. Ready for you to paint on site in any colour you like.
• Painted. Carron paints the radiator in its own spray shop in a colour of your choice, which we confirm with you after you order.
• Hand burnished. A hand-finished metallic look that brings out the detail of the casting.

Painted and hand burnished radiators are finished to order and take longer than stock items, so ask us for the current lead time before you order. Carron advertises over 10,000 paint colours, so you can match a radiator to the walls or pick it out as a feature; choosing a colour that matches the skirting is a classic way to make a radiator recede.

Valves, stays, weight and fitting

Valves are sold separately. Carron's Crocus, Kingsgrove and Daisy wheel valves are solid brass in six finishes, for 15mm pipework with a 1/2 inch radiator bush; the thermostatic versions let each room run at its own temperature. Most designs take Carron wall stays, also sold separately, and the low level models stand on their own feet.

Cast iron is heavy: a 10 section Victorian 4 Column at 460mm weighs about 38kg empty, and deeper designs weigh much more. Have the radiator fitted by a qualified plumber or heating engineer, check the floor can take the weight, and measure the delivered radiator before fixing pipework, because each one is hand assembled and Carron gives sizes as a guide. For assembling extra sections, Carron makes a 900mm radiator assembly tool.

Running a cast iron radiator on electricity

Every radiator here can take a Carron electric heating element: 1200W, 1500W or 2000W, 230V, with a built-in thermostat of about 10°C to 65°C, frost protection and an IPX4 rating. Each radiator listing gives Carron's minimum number of sections for each element. The element is fitted horizontally in a radiator filled with water and inhibitor by a qualified electrician; used as a standalone electric radiator, not connected to central heating, it needs a safety release valve. That makes a cast iron radiator an option for a garden room, extension or flat without a wet heating system.

Looking after cast iron radiators

Cast iron radiators need very little care. Dust them regularly, especially between sections, with a radiator brush. Bleed them at the start of the heating season. Primed radiators should be painted with a paint suitable for radiators once fitted. Keep inhibitor in the system, as your heating engineer will advise, to protect the inside from corrosion. Painted and burnished finishes can be wiped with a soft, damp cloth; avoid abrasive cleaners.

Radiator covers

Prefer to keep a modern radiator and hide it? Carron's cast iron radiator covers put a decorative black cast iron front over it, in a 4 panel design 1580mm wide or a 2 panel design 1790mm wide, with an optional 30mm black granite top that turns the cover into a shelf. They weigh over 150kg, so plan a team to place them.