To fix a water leak on a central heating radiator, turn off the heating, tighten any loose valves, and use a radiator sealant or replace damaged parts as needed.
A leaking radiator can cause water damage and reduce heating efficiency. This guide covers step-by-step solutions for common leaks, from valve issues to pinhole corrosion.
Identifying the Source of the Leak
Before repairs, locate the exact leak source. Common problem areas include:
1. Valve Connections
60% of radiator leaks occur at valve joints. Signs include:
- Water pooling at pipe connections
- Corrosion around valve nuts
- Dripping when valves are partially open
2. Bleed Valve
Check if water escapes from the bleed screw when closed. A worn washer often causes this.
3. Radiator Body
Pinhole leaks appear as:
- Small rust spots (1-2mm diameter)
- Damp patches on the floor
- Cool spots at the radiator base
Fixing Common Leak Types
Leaking Valve Connections
For valve leaks:
- Turn off both radiator valves
- Place a bucket under the drain valve
- Open the drain valve to release water
- Disconnect the leaking valve
- Apply plumber’s tape to threads
- Reconnect and tighten securely
Bleed Valve Leaks
Simple fix:
- Close the bleed valve fully
- Replace the rubber washer
- Apply pipe joint compound
Pinhole Leaks in Radiator Body
Temporary solutions include:
| Method | Duration | Effectiveness |
|---|---|---|
| Epoxy putty | 6-12 months | High |
| Leak sealant | 3-6 months | Medium |
| Rubber patch | 1-3 months | Low |
For permanent fixes, consider radiator replacement if corrosion is extensive.
Preventing Future Leaks
Extend radiator life with these maintenance tips:
- Flush system annually to remove sludge
- Add inhibitor fluid to prevent corrosion
- Check pressure regularly (1-1.5 bar)
- Inspect valves every 6 months
When to Call a Professional
Seek help for:
- Leaks behind walls/under floors
- Multiple pinhole leaks
- Persistent leaks after repair
- Significant water damage
For complex valve issues, consult our guide on heating system controls.
Safety Precautions
Always:
- Turn off heating system first
- Allow radiators to cool completely
- Wear protective gloves
- Have towels and buckets ready
According to Trade Radiators, untreated pinhole leaks can lead to system failure within 6 months. Early detection saves costly repairs.
