Draining a vertical radiator is a straightforward process essential for maintenance, repairs, or system upgrades. By following a clear sequence of steps, you can safely remove water from your radiator and prepare it for further work.
How to Drain a Vertical Radiator?
Draining a vertical radiator involves carefully shutting off the water supply, releasing pressure, and allowing the water to exit the system. This guide will walk you through each step, ensuring a smooth and mess-free process.
Tools You'll Need
Before you begin, gather the following essential tools:
- Adjustable Spanner or Radiator Spanner: For loosening valve nuts.
- Radiator Bleed Key: To open the bleed valve.
- Buckets or Shallow Trays: To collect drained water (multiple might be needed).
- Old Towels or Rags: For spills and protecting floors.
- PTFE Tape (optional): For re-sealing threads upon reassembly.
- Safety Gloves and Eyewear (recommended): For protection.
| Tool Type | Purpose |
|---|---|
| Adjustable Spanner | Loosening and tightening valve nuts |
| Radiator Bleed Key | Opening the radiator bleed valve |
| Buckets/Trays | Collecting drained water |
| Old Towels/Rags | Soaking up spills, protecting floors |
| PTFE Tape | Ensuring a watertight seal upon reassembly |
Step-by-Step Guide to Draining Your Radiator
Follow these detailed steps to effectively drain your vertical radiator:
1. Step 1 - Prep.
Begin by ensuring your central heating system is completely switched off and the water in the radiators has cooled down. Draining hot water can be dangerous and inefficient. Place old towels and buckets directly beneath the radiator valves and the bleed valve to catch any initial drips or larger volumes of water. This preparation minimizes mess and potential damage to your flooring.
2. Step 2 - Shut Thermostatic Radiator Valve (TRV)
Locate the Thermostatic Radiator Valve (TRV), which usually has numbered settings from 0 to 5 or 6. Turn the TRV clockwise to its '0' or 'off' setting. This action closes the valve and stops hot water from flowing into the radiator from the boiler side. Ensure it's fully closed to prevent more water from entering during the draining process.
3. Step 3 - Shut Lockshield Valve
On the opposite side of the radiator, you'll find the lockshield valve. This valve often has a protective cap covering a spindle that can be turned with an adjustable spanner. Before turning, note down the number of turns it takes to fully close the valve (e.g., 2 and a half turns). This is crucial for rebalancing your heating system later. Turn the spindle clockwise until it's completely closed. This stops water from flowing out of the radiator back to the boiler.
4. Step 4 - Remove Thermostatic Radiator Valve Nut
With both valves closed, position a bucket directly under the TRV's connection nut. Using an adjustable spanner, carefully loosen the large nut that connects the TRV to the radiator. Expect some initial water to drip out, as there will be residual water in the valve and connecting pipework. Have your towels ready to absorb any spills. Once loose, carefully pull the TRV away from the radiator, allowing more water to drain into your bucket.
5. Step 5 - Open the Bleed Valve
Now, move to the top of the radiator and locate the bleed valve. Using your radiator bleed key, slowly turn the valve anti-clockwise. You should hear a hiss as air enters the radiator. This is crucial as it breaks the vacuum inside, allowing the water to drain freely from the bottom. Keep the bleed valve open throughout the draining process.
6. Step 6 - Remove the Lockshield Valve Nut
Place another bucket or tray beneath the lockshield valve's connection nut. Similar to the TRV nut, use your adjustable spanner to carefully loosen the nut connecting the lockshield valve to the radiator. As you loosen it, a significant amount of water will begin to flow out of the radiator. Ensure your bucket is well-positioned and be prepared to swap it for an empty one as it fills. This is where the majority of the radiator's water will drain.
7. Step 7 - Drain Any Remaining Water
Once both valve nuts are fully disconnected and the main flow has stopped, tilt the radiator slightly (if possible and safe to do so) to encourage any remaining water to drain out. Continue to manage the water collection with your buckets and towels. If the radiator needs to be removed completely, it's advisable to have someone assist you, as even empty radiators can be heavy. Ensure all water is drained before performing any extensive work.
After Draining
- Repair or Maintenance: Once drained, you can proceed with your planned repairs, replacements, or maintenance.
- Reconnecting: When ready to reconnect, use new PTFE tape on the threads of the valve nuts for a watertight seal. Reconnect the lockshield valve first, then the TRV.
- Refilling and Bleeding: After reconnecting, open the lockshield valve by the exact number of turns you noted down, then open the TRV fully. Refill your central heating system from the boiler. Finally, bleed the radiator from its bleed valve again to release any trapped air and ensure efficient operation.
By following these steps, you can confidently drain your vertical radiator for any necessary home heating system maintenance.
