Fixington

Fit Radiator Thermostat

Trade: Heating Engineer

⭐ Introduction

A radiator thermostat is a small but crucial part of your home heating system. It controls the temperature of each radiator by regulating the flow of hot water, helping you keep rooms comfortable and save energy. Fitting a new radiator thermostat may be needed if your existing valve is broken, outdated, or you want to upgrade to a more efficient model, such as a thermostatic radiator valve (TRV).

This job can improve your heating control, reduce fuel bills, and make your home more environmentally friendly. It’s often done as part of general heating maintenance, during radiator replacement, or to gain better temperature control in individual rooms.

🔧 What the job involves

Fitting a radiator thermostat means removing the old valve (or manual control) and replacing it with a new one. The process includes:

  • Isolating the radiator by turning off your heating and draining water from the relevant part of the system to avoid leaks.
  • Carefully detaching the existing valve from the radiator and pipework.
  • Checking pipe connections and threads for wear or damage.
  • Installing the new radiator thermostat, which typically screws onto the valve body or radiator inlet.
  • Refilling the heating system, bleeding the radiator to remove trapped air, and testing the new thermostat for proper function.

Thermostatic valves automatically adjust the radiator’s heat output in response to air temperature, meaning you get more consistent warmth and can lower your heating bills.

📝 Step-by-step from booking to completion

  1. Make an enquiry – Contact a registered heating engineer for advice and to arrange a visit. Ensure they are Gas Safe registered if working on any gas appliances nearby.
  2. Survey and quote – The engineer will inspect your radiator, pipework, and existing valves to confirm compatibility and provide a written estimate.
  3. Schedule the work – Agree on a date for installation based on your availability and the engineer’s schedule.
  4. Preparation – On the day, clear the area around the radiator to give the engineer easy access.
  5. Installation – The engineer will turn off and drain your heating system as needed, remove the old valve, fit the new thermostat, and carry out final tests.
  6. Completion and advice – They will explain how to use the new thermostat, check for leaks, ensure the radiator is working well, and provide any necessary paperwork or warranty details.

💷 Main costs to expect

  • Labour: Heating engineer’s time, typically charged hourly or a flat rate for the valve fitting.
  • Parts: Cost of the radiator thermostat valve itself, usually a few tens of pounds for a basic model. More complex or smart TRVs cost more.
  • Disposal: Removal and responsible disposal of your old valve, if applicable.
  • Certification: While fitting radiator valves doesn’t usually require specific certificates, keeping a work report or receipt is advised.
  • Extras: If pipework repair or radiator bleeding is necessary, these may add to costs.

Example:

  • Labour (1–2 hours): £60–£120
  • Radiator thermostat valve: £15–£50
  • Disposal and minor materials: £10–£20
  • Total estimate (excluding VAT): £85–£190

📊 What affects the price

  • Access to radiator: Tight corners or awkward places take longer to work in.
  • Type of valve: Simple manual valves cost less than thermostatic or smart valves.
  • Pipework condition: If pipes are corroded or capped poorly, repairs add time and cost.
  • Number of radiators: Fitting multiple valves in one visit usually reduces per-valve cost.
  • Heating system type: Some systems require more careful draining or specific handling.
  • Urgency and scheduling: Short-notice or out-of-hours jobs tend to be pricier.
  • Location: Prices in London or the South East may be higher than in other regions.

⏱ How long does it take?

  • Straight swap of a single radiator thermostat: Typically 1 to 2 hours including draining and refilling the system, bleeding the radiator, and testing the valve.
  • Multiple valves or complicated systems: 2–4 hours, depending on quantity and complexity.
  • Installing smart or programmable TRVs: May take longer due to additional setup and testing.
  • If pipework repairs or radiator removal is needed: Additional time will be necessary.

🏠 Can you DIY it?

While fitting a radiator thermostat is technically possible for confident DIYers with basic plumbing tools, it’s not always straightforward. You’ll need to:

  • Turn off and drain part of your heating system (which risks leaks and water damage if not done properly).
  • Have some plumbing knowledge to avoid damaging pipe threads or causing leaks.
  • Know how to bleed radiators correctly.

Bear in mind:

  • There are no legal restrictions specifically preventing DIY fitting of radiator thermostats, but working on pressurised heating systems requires care.
  • If you’re uncomfortable with draining or pipework, or unsure about tools and procedures, it’s safer and more efficient to hire a Gas Safe-registered heating engineer or certified plumber.
  • Incorrect installation can cause leaks, damage the heating system, or reduce energy efficiency.

💰 Typical UK price range

For fitting a radiator thermostat, expect to pay approximately £80 to £200 excluding VAT. This covers labour and a standard thermostat valve. VAT at 20% usually applies if the work is done by a VAT-registered business.

Prices can vary depending on the factors mentioned earlier, so always ask for a detailed quote before proceeding.

✅ Handy tips before you start

  • Clear the area around the radiator to help the engineer work efficiently.
  • Turn off your heating and allow radiators to cool well in advance of the appointment.
  • Check your system type, so you can inform the engineer (e.g. combi boiler, system boiler, heat only).
  • Keep paperwork including quotes, invoices, and any manufacturer warranties from the new valve.
  • Regularly bleed your radiators to maintain efficiency.
  • Consider upgrading several valves together to improve overall home comfort and savings.
  • Ask for advice on using the thermostat valve effectively to reduce your heating costs.
  • Ensure proper disposal of old valves with the engineer—avoid putting parts in household waste.

Fitting a radiator thermostat can be a relatively simple yet worthwhile improvement to your home heating. With the right professional help, you’ll enjoy better temperature control and lower energy bills throughout the year.