Immersion Heater Replacement

What immersion heater replacement covers

You get a targeted fix for hot water cylinders that rely on an immersion element, with clear advice on whether replacement is the best option.

• Fault diagnosis for no hot water, slow heat-up, or a tripping fuse/MCB
• Isolation of electrical supply and safe working practices
• Replacement of the immersion element (and boss seal where required)
• Replacement of thermostat and high-limit safety cut-out if faulty
• Checks for leaks, signs of overheating, and damaged wiring or terminals
• Refill and heat-up test to confirm correct operation
• Advice on settings and energy use to help keep running costs sensible

Who this service is for

This service suits homeowners, landlords, and small commercial sites that need hot water back quickly and want the job done properly first time. It’s also ideal where you want a clear explanation of what failed, what will be replaced, and what to expect from the system afterwards.

Common situations include:

• No hot water from the cylinder but cold supply is fine
• Hot water runs out quickly or takes too long to reheat
• The immersion keeps tripping the electrics
• A leak from the immersion heater housing or cylinder boss area
• The thermostat is inaccurate or the water is overheating

What’s involved and how the work is carried out

The work starts with confirming the cylinder type and the likely cause of failure (element, thermostat, wiring, or controls). The supply is isolated, then the element is removed and replaced using suitable parts and seals.

Once fitted, the cylinder is brought back into service and checked for leaks. Electrical and functional checks are completed so you can be confident the heater is operating safely and heating correctly.

If your cylinder is unvented, the system and its safety components need the right approach and compliance. Any work on unvented hot water systems should be completed by an appropriately qualified engineer.

After replacement: performance, safety, and next steps

After testing, you’ll know the heater is cutting in and out correctly and the safety controls are working. You’ll also get practical guidance on thermostat settings, off-peak use (where relevant), and signs to watch for that may indicate a wider cylinder or control issue.

If repeated failures are likely due to limescale, corrosion, or an ageing cylinder, you’ll be advised on realistic options so you can plan ahead rather than face repeated breakdowns.