Category: Plumbing

Radiator leak repair

A radiator or towel rail is dripping and there's a puddle underneath — don't wait. Hot water under pressure can ruin the floor and flood the neighbours within hours. Here's what to do right away and how to solve it properly.

First: relieve pressure and stop the water

  • Close the shut-off valves on the supply lines to the radiator — usually one on each end, top and bottom.
  • If there are no valves (sometimes the case in older buildings) — shut off the heating riser, or the hot water if it's a DHW-connected towel rail.
  • Place a container under the leak and soak up water.
  • Don't try to tighten joints "with force" — hot metal can shear off and you'll get a fountain.

Typical leak locations and causes

  • Threaded joint between sections — the seal dries out, especially on cast iron and older aluminium radiators.
  • Air bleed valve or drain valve — worn seal or damaged thread.
  • Supply line (hose) — flexible hose is rated for 5–7 years, then it bursts.
  • Pinhole in the section itself — corrosion, especially in steel panel radiators.
  • Thermostatic head or shut-off valve — most often leaks at the stem where the gland has worn.

What a pro can do

  • Replace seals in threaded joints or repack the union.
  • Swap shut-off valves, thermostatic head, air bleed valve — cheap individual parts.
  • Weld a pinhole (for steel and cast iron) or fit a clamp.
  • Replace a single section or the entire radiator.

If the radiator is 20+ years old and it's leaking through the metal rather than a thread, replacing the whole radiator is the sensible move: a patch buys a couple more months before another swap.

How much it costs in Israel

  • Replacing a flex hose or one valve — 250–400 ₪
  • Repacking a section joint — 350–600 ₪
  • Thermostatic head replacement with setup — 300–500 ₪
  • Full radiator replacement (labour only, radiator not included) — 600–1,200 ₪
  • Towel rail replacement with re-plumbed connection — from 800 ₪

What if the building is on central heating?

Central hot-water heating is rare in Israel — usually it's autonomous systems or electric convectors. But if a central-system water radiator does leak, don't shut off the riser yourself — contact the building management or utility. You can catch water in a bucket in the meantime, but the actual work happens after the riser is isolated.

FAQ

Can I tighten a nut on a leaking radiator?

A gentle tightening on a union nut sometimes helps with a fresh weep. But if the thread is seized or the radiator is old, a single pull can break the joint and turn a drip into a gush. Better to shut the water off first and call a pro.

How much does radiator replacement cost in Israel?

Plumber's labour for a radiator swap is 600–1,200 ₪, and the radiator itself (depending on type and size) is another 300–1,500 ₪. A towel rail with re-plumbed connection starts at 800 ₪ for labour plus the unit.

Towel rail is leaking — is it urgent?

Yes, especially if it's connected to the domestic hot water system — the water is constantly under pressure. Until the plumber arrives, close the supply valves or the main hot water valve in the bathroom.

Who handles radiators — a plumber or a specialist?

In Israel it's usually the same plumber (אינסטלטור) with experience on heating and DHW systems. On KABLAY those pros are listed under "Plumbing".