Fixington

Fix a radiator which isn’t heating up correctly

Trade: Heating Engineer

⭐ Introduction

If one of your radiators isn’t heating up as it should, it’s more than just inconvenient—it can affect the comfort of your whole home. Radiators that are cold or unevenly warm might be suffering from issues such as trapped air, faulty valves, sludge build-up, or even leaks. Fixing a radiator that isn’t heating up properly ensures your heating system works efficiently, helps reduce energy bills, and keeps your home cosy during the colder months.

This job is usually carried out by a qualified heating engineer, especially if it involves working on the central heating system. Regular maintenance or early repairs can prevent more significant problems later.

🔧 What the job involves

Fixing a radiator that isn’t heating correctly generally includes a few common checks and tasks:

  • Bleeding the radiator: This is the simplest fix. Air trapped inside the radiator stops hot water from circulating properly. Using a radiator key to release the air often solves the problem.

  • Checking and adjusting valves: Thermostatic Radiator Valves (TRVs) or lockshield valves might be stuck or faulty, preventing proper flow.

  • Flushing the system: Over time, sludge and corrosion can build up inside the radiator or pipework, restricting water flow.

  • Repairing leaks or replacing parts: If there’s a leak or a valve is damaged, it needs to be fixed or swapped out.

  • Balancing the system: Ensures all radiators get an equal share of hot water.

The engineer will also inspect your boiler and any controls if needed to ensure the overall heating system is functioning correctly.

📝 Step-by-step from booking to completion

  1. Enquire and describe the problem: Contact a Gas Safe registered heating engineer. Give details about the radiator and symptoms.

  2. Survey and diagnosis: The engineer visits to inspect the radiator and heating system, identifying the cause.

  3. Quote and authorisation: You receive a clear, written quote outlining the work and costs. You approve the quote.

  4. Schedule the repair: Book a convenient date for the engineer to carry out the work.

  5. On the day: Engineer arrives, sets up tools, and performs the repair. This may include bleeding, valve adjustment, flushing, or part replacement.

  6. Testing and confirmation: The engineer tests the radiator heating and overall system performance.

  7. Clean-up: Any waste or old parts are removed, and the work area is tidied.

  8. Documentation: You receive any relevant certificates or guarantees. The engineer advises on aftercare.

💷 Main costs to expect

  • Labour: Typically £50–£80 per hour, depending on location and experience.

  • Materials and parts: Radiator valves approximately £15–£50 each, radiator keys under £10, flushing chemicals around £20–£40.

  • Additional repairs: Replacement radiators from £100 upwards, depending on size and type.

  • Disposal: Waste radiators or parts may incur a small fee, about £10–£20.

  • Certification: Not usually required unless other regulated work is involved, but engineers will provide receipts or guarantees.

📊 What affects the price

  • Access: Radiators in hard-to-reach places or upstairs may cost more.

  • Complexity: Flushing a whole system or replacing parts takes longer.

  • Regulations: If the work involves gas boiler adjustments, only a Gas Safe registered engineer can do this.

  • Remedial works: Corroded pipework or leaks that require additional repair.

  • Location: Some regions have higher labour rates.

  • Timeline: Emergency call-outs or urgent repairs might attract a premium.

⏱ How long does it take?

  • Bleeding a radiator: Usually 15–30 minutes per radiator.

  • Valve replacement: Around 30–60 minutes per valve.

  • Flushing a radiator: About 1–2 hours.

  • Full system flush: Can take 4–8 hours or more, often scheduled over a day.

  • Replacing a radiator: 1–3 hours depending on size and pipework complexity.

🏠 Can you DIY it?

For simple tasks like bleeding a radiator, many homeowners can manage with a radiator key and some care. It’s a quick fix that improves heating efficiency.

However, anything involving valves, pipework, leaks, or boiler system requires professional expertise. Working on central heating systems can involve hot water and gas components, so errors can be dangerous and costly.

If in doubt, and to comply with UK safety standards, always hire a Gas Safe registered heating engineer. This is especially important if you suspect gas appliance issues or require gas-related repairs.

💰 Typical UK price range

Fixing a radiator that isn’t heating properly generally costs between £60 and £250 depending on the work needed. This estimate includes labour and basic parts, but excludes large replacements or full system services. All prices usually exclude VAT, currently 20%, unless the engineer is VAT-registered.

Simple bleeding and valve adjustments tend towards the lower end, while flushing or part replacements can increase the price.

✅ Handy tips before you start

  • Locate your radiator keys and ensure you know how to use one safely.

  • Turn off your central heating system before bleeding or work to avoid hot water sprays.

  • Check the system pressure gauge on your boiler after bleeding; you might need to top up the pressure.

  • Keep all paperwork, quotes, and receipts from your heating engineer for warranty and future servicing.

  • Arrange regular boiler and system servicing through a Gas Safe registered engineer to maintain efficiency and safety.

  • If your heating engineer recommends flushing the whole system, ask about PowerFlush or chemical flushing depending on sludge severity.

Addressing radiator heating issues promptly saves you money on energy bills and prevents more serious system failures later on.