Radiator leak (C) Daniel Friedman Guide to Finding & Fixing Leaks in Heating Radiators, Baseboards & Convectors

  • LEAKS at BASEBOARD, CONVECTOR, RADIATOR - CONTENTS: Where to Check for Leaks on Baseboards, Radiators, or Heating Convectors - How to identify, inspect, diagnose, and repair problems with hot water or steam radiators, baseboards, or heating convectors. Where leaks occur on hot water and steam radiators, convectors, and baseboards. Guide to unusual radiators, baseboards, and heating convectors in buildings. If your radiator or baseboard is cold and the heating system is "on" - here we diagnose the problem
  • POST a QUESTION or READ FAQs about diagnosing & fixing leaks in hot water or steam heat radiators

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Heating radiator leak troubleshooting:

This article describes how to find and fix leaks in hot water heating radiators. We describe the types and locations of leaks found on heating radiators: hot water, steam, cast iron, heat convectors, baseboard heat, electric heating convectors.

Our page top photo shows a common point of leakage on cast iron radiators, between abutting radiator sections near the bottom of the unit.

This article series answers most questions about all types of heating systems and gives important inspection, safety, and repair advice. In addition to cast iron radiators using hot water or steam as a heat source, we describe two other very common hot water heat distribution methods below.

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Where to Check for Leaks on Baseboards, Radiators, or Heating Convectors

Article Contents:

Here are some common leak locations on baseboard heating systems

Heating baseboard leak (C) Daniel Friedman Heating baseboard leak (C) Daniel Friedman

Obviously, first look at the floor around each heating component to see if you see water stains or water damage. (Water damage can occur at steam radiators too, as condensate could be leaking at the condensate return pipe fittings.)

If you don't know what kind of heat your building uses, we explain how to figure out the answer at HEATING SYSTEM TYPES.

If your heating system is not working properly, see NO HEAT - BOILER or NO HEAT - FURNACE.

On heating systems using hot water baseboards, leaks can occur anywhere in the piping system, including at air bleeders located at the ends of baseboard sections, at couplings or elbows in the piping system, or where freezing has cracked or burst a heating baseboard pipe.

Our photo of a leaky heating baseboard (above left) shows that prolonged leaks may rot carpeting (leaving an obvious leak clue once someone vacuums up the ruined carpet at this spot) and may also cause hidden damage to the subfloor or even the structure. Or perhaps a mold problem may result.

Our baseboard piping leak photo (above right) shows how freezing pipes may cause separation at a solder joint instead of actually bursting the piping. In the case shown, the original solder joint had been poorly made, so this was a weak point that broke first.

Leaks at heating baseboard air bleed valves are shown at AIR BLEEDER VALVES. If your heating baseboards are not in fact getting warm when your thermostat is calling for heat and the boiler is indeed running, see AIRBOUND HEAT SYSTEM REPAIR

Also see WINTERIZE A BUILDING for examples of freeze-burst copper forced hot water heating piping in a baseboard heat system.

Here are some other common leak locations on hydronic or steam radiators

Leaks occur between sections of cast iron hot water or steam radiators.

Splits and leaks in a cast iron radiator (C) Daniel Friedman Leaky steam radiator (C) Daniel Friedman

The radiator may leak where sections of cast iron are bolted together, or if the radiator has rusted-through or become cracked, perhaps by freezing, you may see rust and leak stains at splits in the individual radiator sections (photo at above left) .

While an individual, accessible crack in a cast iron radiator might submit to an epoxy repair, extensive damage such as we show above usually means the heating radiator should be replaced.

Radiator leak (C) Daniel Friedman Radiator valve leaks (C) Carson Dunlop Associates

Sometimes a leak at a steam radiator is not critical - you may at least make it through the heating season, or the leaking may occur only when the radiator is cold (photo, above-right, also shown at page top, of a leaky steam radiator). This is a steam condensate leak.

If you see rust stains and leak indications between radiator sections at the top of the radiator, such as in our photo (above-left), or other rust, splits, or evidence of leakage from the body of the radiator, we recommend that you ask for repair advice from your heating service company.

Leaks also occur at radiator valves, at radiator bleed valves, and at the piping fittings where valves and pipes join the radiator bottom or top.

As Carson Dunlop's sketch (left) warns, watch out for hidden structural damage or damaged ceilings below leaky radiator valves.



Continue reading at STEAM RADIATOR VENT REPAIR if your radiator leaks are at a steam radiator vent or select a topic from the More Reading links shown below.

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LEAKS at BASEBOARD, CONVECTOR, RADIATOR at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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