Good to know
Questions about the radiators
Why is there no price on the button?
Because the price includes the valves, the fittings, the pipe run and whether we are installing it. Ask and we will price your job, usually the same day.
What does “output at ΔT50” mean, and why does it matter so much?
It is the standard catalogue test condition: water in at about 85°C, out at 75°C, room at 20°C. Every manufacturer quotes it, which makes ranges comparable. A heat pump makes 45–55°C water, because that is where it is efficient. At those temperatures a radiator gives roughly half its catalogue figure, which is why radiators on a heat pump are sized bigger than radiators on a gas boiler. We do that sizing for you.
Aluminium or steel — which should I pick?
Aluminium (Fondital) holds very little water, so it warms and cools quickly and weighs less. Steel panel (Brugman) holds more water, is steadier, and gives you more output per dollar in the bigger sizes. In a room you want up fast, aluminium. In a big living space on a heat pump, a Type 22 steel panel is usually the better buy. We will tell you which we would fit and why.
Can I put radiators on the same system as underfloor heating?
Yes. The slab heats the ground floor and radiators heat the upper floor or rooms without a new slab. One heat pump, one set of controls. The two need different water temperatures, so the design has to allow for that — usually with a mixing arrangement at the manifold.
Do you fit towel rails on the same system?
Yes. Heated towel rails run off the same hydronic circuit, so they cost little extra to run and have no element. Tell us which bathrooms and we will include them in the price.
Do you sell to trade, or only fit them yourselves?
Both. If you are a plumber or a builder and you want the units supplied, ask for trade pricing. We also design, supply and install them.
How long do they take to get?
These are stocked ranges in New Zealand, so common sizes are usually days rather than months. Tall verticals and less common lengths can take longer. We will confirm the real lead time when we price it.
What guarantee comes with them?
Brugman steel panels carry a ten-year conditional manufacturer’s guarantee. Fondital aluminium is covered by the manufacturer’s warranty through the New Zealand distributor. Our own workmanship is guaranteed separately, and we service what we install.
Are these available in New Zealand?
Yes. Castrads are made in Manchester and distributed in New Zealand by Waterware. We can supply and install any model, finish and valve in this range. They are made to order rather than held in stock, so they are not a next-day item — Castrads quote roughly four weeks from the factory and we confirm the real landed date with Waterware when we price your job.
Why is the output figure so much smaller than on your other radiator page?
Because it is a different number measured a different way. Cast iron is sold by the section, so the figure here is the output of one section — a Mercury 3 Column 660 mm at 66 W per section is 792 W as a twelve-section radiator. It is also quoted at ΔT60 rather than the ΔT50 used on our Fondital and Brugman tables, which makes it read about 20% higher again for the same piece of iron. Compare like with like, or better, let us do the heat loss calculation.
Will cast iron work on a heat pump?
Yes. Castrads build every hydronic model to take a thermostatic valve, so they are compatible with a low-temperature system. As with any radiator on a heat pump, at 45–55°C flow the output is roughly half the catalogue figure, so more sections are needed. Cast iron holds a lot of water and warms up slowly, which suits a heat pump running long and steady.
How heavy are they, and will my wall or floor take it?
Cast iron radiators are heavy, particularly when full of water. Floor-standing models sit on their own feet but should have a Whitworth wall stay to stop them being pushed over. Wall-hung models — Vulcan, and the wall-hung options on Mercury, Grace and Emmeline — need a substrate that can carry the load. We check this on site before we quote.
Can I get one in a specific colour?
Usually, yes. There are 24 Castrads exclusive finishes, and Castrads will also match any colour from Farrow & Ball, Little Greene, Paint & Paper Library or Benjamin Moore, using the branded paint under licence. Florence steel adds 33 specialist powder-coat finishes and over 180 RAL colours. Bring us a paint chip.
What about bay windows and curved walls?
Florence steel column radiators can be made curved, in any height up to 1800 mm, with welded feet as standard. It is recommended for the 2, 3 and 4 column models. We need two measurements — the chord (the straight width across the bay) and the camber (the depth from the middle of that line back to the wall). We take those for you.
Is there a guarantee?
Castrads' Ironshield Guarantee is ten years as standard on the radiators and five years on the valves, and does not set conditions on water pH or system flushing. Our own workmanship is guaranteed separately, and we service what we install.
Can I buy just the radiators, without installation?
Yes. If you are a plumber, a builder or an architect specifying for a client, we can supply the units and the valves on their own — ask for trade pricing. We can also design, size, supply and install them.
How do these compare on price to a standard panel radiator?
Considerably more. Cast iron is usually chosen for rooms where the radiator is on show, such as a hallway, a living room or a period villa. Many of our jobs use both: cast iron where it is on show and panel radiators elsewhere.
Do you service cast iron radiators you did not supply?
Yes, including old ones. Bleeding, balancing, valve and lockshield replacement, radiators that are cold at the bottom, and refurbishment jobs where the radiators are staying but the plant is being replaced. Castrads also sell bleed valves separately for exactly that kind of restoration work.
Sizes, model codes and
outputs are the current New Zealand catalogue figures from the distributor and are subject to change
without notice. Champion Heating is an independent installer and is not affiliated with Fondital or
Brugman; brand names are used to identify the products we supply.