Radiators 

Upgrade your old, poorly performing radiators

Old radiators can become less effective over time as sludge and corrosion debris build up inside them. If some radiators take a long time to heat, have cold patches—often near the bottom—or leave rooms chilly, it may be time to have them checked.

Replacing a radiator that’s internally restricted by sludge can help hot water circulate through the new radiator more freely and deliver heat to the room more effectively. The result depends on the condition and design of the whole heating system, so I’ll check the existing setup and help you choose a suitable replacement.

How sludge affects your heating system

As radiators and pipework age, corrosion can create dark deposits and debris that collect in the system. This sludge can settle inside radiators and restrict water flow, leaving parts of the radiator cooler than they should be. Your boiler may then need to run for longer to reach the temperature you want, while some rooms remain uncomfortable.

Sludge can also circulate through the heating system and contribute to wear or blockages in components such as valves and pumps. Replacing a badly affected radiator can remove that radiator as a source of restriction and help restore heat output—but if sludge is present elsewhere, replacing radiators alone may not clear the whole system. Further cleaning may be worth discussing.

Type 11 and Type 22 radiators

Radiator types describe the arrangement of panels and convector fins:

- Type 11: one panel and one set of convector fins. It is slimmer and can suit tighter spaces.
- Type 22: two panels and two sets of convector fins. It is thicker and generally provides more heat output than a Type 11 of the same height and width.

The right type and size depend on the room’s heating needs and the space available. I can help you choose an appropriate option.

Radiator valves explained

Radiator valves control how hot water flows through each radiator:

- Thermostatic radiator valve (TRV): senses the temperature around it and adjusts the flow of hot water to help maintain the selected room temperature. This gives you individual control in each room.
- **Lockshield valve:** controls the radiator’s flow rate as part of balancing the system. It is usually adjusted during setup and left in place, rather than used for everyday temperature changes.

Balancing your heating system

After fitting the radiators, I’ll balance the system by adjusting the lockshield valves so hot water is distributed more appropriately around the home. Without balancing, radiators closer to the boiler or pump may receive more flow, while those further away may heat more slowly or unevenly.

Balancing helps each radiator receive a suitable flow of hot water, improving consistency between rooms and helping the system operate as intended. It can reduce hot and cold spots and avoid needing to turn the heating up just because one room is lagging behind. The final result also depends on factors such as the boiler, pump, pipework and radiator sizing. caleffi.com

 
Adding inhibitor to the system

When installing new radiators, I’ll add central-heating inhibitor to the system. Inhibitor helps limit corrosion and the formation of sludge inside radiators and pipework. It helps protect the new radiators and other heating components, but it does not remove heavy existing sludge—if the system is badly contaminated, cleaning may also be needed.

Should you upgrade your central-heating pump too?

If your pump is old, noisy or struggling to circulate water around the system, it may be worth having it checked while replacing radiators. Symptoms such as slow or uneven heating, pump noise, or radiators that are difficult to balance can have several causes, but the pump is one component to consider.

A new radiator does not automatically need more pumping pressure. The pump needs to be suitable for the system and its resistance; simply fitting a more powerful pump isn’t always the answer. If the pump is worn or unsuitable, upgrading it at the same time may help provide reliable circulation and avoid paying for a separate visit later. I can assess whether an upgrade is appropriate for your system.

See my central-heating pump installation page for more information.

What the installation involves

I’ll check the existing radiator, pipework, valves and available space, then help select a suitable replacement. I’ll isolate or drain the relevant part of the system, remove the old radiator and fit the new one with the required valves. After installation, I’ll refill the system, add inhibitor, check for leaks, confirm the radiator heats up and balance the system.

Radiator installation prices

The fitting price per radiator depends on how many are being installed:
 

Rough costs depending on size of radiator, type and pipework

- 1 radiator: £350
- 2–4 radiators: £275 per radiator
- 4–6 radiators: £260 per radiator
- More than 6 radiators: £250 per radiator

Arrange a radiator installation

To discuss replacing one radiator or upgrading several, call or text Mark on 07887 425281. I cover Ash Vale and the surrounding area.