Replacing a radiator: when is it time and what does it cost?

A radiator can last a long time, but at some point replacement makes more sense than repair. How do you know when that moment has arrived, what should it cost, and what do you look for in a new radiator?

When is replacement the right call?

There are clear signs that a radiator needs replacing:

• Leaking — internally or at the connections. Small leaks can be fixed, but internal rust or multiple leak points indicate a structural problem.
• Poor heat output — the radiator does not warm up properly even after bleeding. Can indicate sludge build-up or internal corrosion.
• Persistent air in the system — the system keeps drawing in air even after frequent bleeding.
• Switching to a heat pump — when moving to low-temperature heating, existing steel radiators are often undersized.
• Renovation — you are rearranging a bathroom or room and the existing model no longer fits.

What does a new radiator cost?

Design radiators vary considerably in price:

• Affordable entry level (e.g. Oval Delux): from around €375
• Mid-range models (e.g. Libra, Pure): €349–€950
• Premium horizontal models (e.g. Nexo): from €1,185
• Custom or statement models (e.g. Model O, Monotile): €720 and above

Installation costs come on top. A plumber typically charges €80–€200 per radiator for a standard swap, depending on the situation and location. Heatnest also offers installation service.

What size do I need for a replacement?

Use the dimensions of the existing radiator as a starting point, but verify the heat output. If the house has been renovated or if you are switching to a heat pump, you should recalculate the required output.

Read more in what size radiator do I need or ask for advice.

Adapting connections

When replacing, also check the connection position and size (½ or ¾ inch). Heatnest models come with standard connections. Your installer can advise if adjustments are needed.

Durability and service life

A steel radiator typically lasts 15–25 years depending on water quality and maintenance. Aluminium radiators are inherently rust-resistant and structurally longer-lasting — Heatnest offers 15 years factory warranty.

Replacement is the right moment to switch to a model that better fits your current system, heating needs and interior. See the full range on the products page.

In summary

Replacement makes sense when there is a leak, poor heat output, renovation or a switch to a heat pump. Use the moment to resize correctly, choose a better material and improve the look of the room. Ask for personal advice if unsure — it is free with Heatnest.