Why Your Radiators Might Be Cold Even After Bleeding
If you’ve just bled your radiators in Selborne (GU34) but still find some staying chilly, you’re not alone. Bleeding removes trapped air, but it doesn’t always fix uneven heat distribution. In older properties—or those with several radiators—system balancing is often needed to ensure every unit heats evenly.
What Is Heating System Balancing?
Balancing means adjusting the flow of hot water so each radiator gets its fair share of heat. In an unbalanced system, radiators closest to the boiler get too much flow and pipework further away remain cold, even after bleeding. This is a common issue in Selborne homes with multiple radiators spread over two floors.
Signs Your System Needs Rebalancing
- Some radiators heat up quickly while others stay cold
- Rooms at the end of a circuit (e.g., in Whitehill or Alton) don’t reach the desired temperature
- Increased energy bills despite regular boiler servicing
- Frequent heating breakdown call-outs due to overworking the boiler
Why Selborne’s Older Pipe Layouts Can Be Tricky
Properties in Selborne and nearby Liphook often feature original pipework or gravity-fed systems. These lack modern manifolds and can suffer from imbalance as new radiators or extensions have been added over time. If your heating engineer only bleeds radiators without checking flow rates, cold spots will persist.
How to Balance Your Radiators: A Step-by-Step Guide
While a qualified Gas Safe engineer should perform full system balancing, you can carry out preliminary checks yourself. Follow these steps to identify imbalance and prepare for a professional service.
1. Bleed All Radiators First
Even if you’ve done this already, repeat the process to ensure maximum air removal. Work from the lowest radiator up to the highest:
- Turn off the boiler and wait for the system to cool.
- Use a radiator key to open the bleed valve until air hisses out.
- When water drips steadily, close the valve.
2. Check System Pressure
On your boiler control panel, ensure the pressure gauge reads between 1 and 1.5 bar. Low pressure can prevent adequate flow to distant radiators. If needed, repressurise according to the manufacturer’s instructions.
3. Identify the Flow and Return Pipes
Feel the inlet and outlet pipes on each radiator. The pipe closest to the boiler is the flow; the cooler side is the return. Radiators that barely warm indicate restricted flow.
4. Adjust Lockshield Valves
The lockshield valve controls how much hot water enters each radiator. It usually has a plastic cap. To balance:
- Use an adjustable spanner to open the lockshield fully, then close it by the number of turns recommended (often 1¼ turns).
- Turn the boiler back on and let the system reach temperature.
- Work radiator by radiator, starting closest to the boiler (often in GU35 Bordon homes), then gradually closing valves on radiators further away (e.g., in Petersfield or Farnham) until each reaches similar heat.
Common Pitfalls and When to Call a Professional
Balancing can be fiddly. You may encounter:
- Stiff or seized valves – forcing them can cause leaks.
- Sludge buildup – a chemical flush may be needed to clear debris so water flows freely.
- Incorrect radiator sizing – old radiators in Haslemere or Hindhead properties may not output enough heat if undersized.
For thorough work, contact our Gas Safe engineers for a power flush or full inspection. Regular boiler servicing helps prevent sludge and maintains efficiency.
When to Upgrade Your System
If you’re extending your home in Liss, adding en-suite radiators, or still using a 20-year-old boiler, consider a system overhaul. A new boiler and smart controls can transform heating performance:
- Modern condensing boilers adjust output precisely.
- Smart thermostatic radiator valves (TRVs) allow room-by-room temperature control.
- Manifold systems deliver balanced flow without constant valve adjustments.
Speak to us about a new boiler installation or explore our affordable boiler cover options to protect your investment.
Frequently Asked Questions
Why do I still have cold spots after bleeding my radiators?
Bleeding removes trapped air but won’t fix uneven water flow. Balancing the system by adjusting lockshield valves ensures each radiator gets the correct flow.
How often should I balance my heating system?
We recommend checking balance annually, ideally alongside your boiler service. Changes in usage or new radiators can shift the equilibrium.
Can I balance radiators myself or do I need an engineer?
Basic checks like bleeding and valve adjustments can be DIY, but a full system balance and power flush require a qualified Gas Safe engineer.
Is balancing worth it if I plan to upgrade my boiler soon?
Yes. Properly balanced radiators improve current comfort and help a new boiler operate at peak efficiency.
If you need help balancing your radiators or have any heating breakdown, our local engineers in Selborne are ready to assist. Call us on (01420) 558993 or book online at embassygas.com/book.
Written by Embassy Gas — your local heating experts covering Selborne, Bordon, Liphook, Farnham and surrounding areas.