Hot water backup · Ireland
Immersion Heater Replacement in Ireland: Cost and What to Expect
A new immersion element, thermostat or timer for your hot water cylinder, with county-by-county guidance on what it costs, single versus dual element, what the job involves, and when the wiring needs a registered electrician.
The short version
Immersion heater replacement in Ireland costs €150 to €300 for a new element fitted in 2026, and €80 to €200 for a timer or thermostat. It is the electric backup that heats your hot water cylinder when the boiler is off or down, and it is a small, same-day job in most homes. Choose your county below for local prices and plumbers, or read on for the options, the 2026 costs, and what happens on the day.
Whether the element has burnt out in a Dublin apartment, the water runs lukewarm in a rural bungalow, or the immersion keeps tripping the fuse board, the same few things decide the job: which part has failed, whether your cylinder takes a single or dual element, and the condition of the wiring behind the switch. The element and thermostat sit inside the cylinder, but the electrical supply feeding it is a job for a registered electrician, so it often pays to confirm who does what before you book.
The basics
Why an Immersion Heater Still Matters
The immersion is the electric heater inside your hot water cylinder, and for most Irish homes it is the backup that keeps the hot water going when the boiler is off, out of oil or waiting on a repair. Flip the switch on the wall and it heats the tank on electricity alone.
It earns its keep in apartments with no gas or oil boiler, in homes over the summer when you would rather not fire the whole heating system, and in any house where the boiler is down and you still need a hot shower. A working immersion is cheap insurance against a cold morning.
- Heats the cylinder on electricity, independent of the boiler
- The go-to backup when the boiler is off or down
- Common in apartments with no gas or oil heating
When to replace
Signs Your Immersion Heater Needs Replacing
An immersion heater usually fails part by part rather than all at once. If yours has stopped heating, is slow to warm the tank, or keeps tripping the fuse board, these are the signs Irish plumbers see most before a replacement.
No Hot Water From the Immersion
You switch it on and the water stays cold. A burnt-out element is the usual cause, and it is the most common immersion failure.
Slow to Heat the Tank
The immersion runs far longer than it used to for a full tank, which points to an element furred with scale or on its way out.
Keeps Tripping the Fuse Board
An immersion that trips the RCD or blows a fuse when switched on usually means a failed element or damaged wiring, and needs checking straight away.
Old Element Scaled Up
In hard-water areas the element crusts with limescale over the years, which slows heating and shortens its life.
Water Too Hot or Too Cold
Scalding water or a tank that never gets properly hot usually points to a failed cylinder thermostat rather than the element itself.
Timer Not Working
If the immersion no longer comes on when set, or runs at the wrong times, the timer or its wiring has failed and needs replacing.
The options
Immersion Heater Options in Ireland
Single element, dual element, a timer and thermostat, or an off-peak setup: each suits a different cylinder and budget. Here is what sets them apart before you get a quote.
Single Element
One heating element fitted low in the cylinder to heat the full tank. The standard setup in most Irish homes and the simplest to replace, ideal as a straightforward backup to the boiler.
from€150
Dual Element
Two elements in the one cylinder, a short one near the top for a quick boost of a few litres, and a full-length one for a complete tank. Handy where you want a fast top-up without heating everything.
from€200
Timer and Thermostat
A timer sets when the immersion comes on and a cylinder thermostat sets how hot it gets. Together they stop the immersion running all day and keep the water at a safe, steady temperature.
from€80
Eco or Off-Peak
The immersion wired to a night-rate or off-peak electricity setup so the tank heats on cheaper hours. Best suited to homes on a day and night meter, and set up by a registered electrician.
from€120
2026 prices
How Much Does Immersion Heater Replacement Cost in Ireland?
Immersion heater replacement in Ireland costs €150 to €300 for a new element supplied and fitted in 2026, with labour and VAT included. A timer or thermostat swap is cheaper, while a dual element or new wiring at the fuse board sits at the top.
- Get the part named on the quote, element, thermostat or timer
- A badly scaled cylinder may need draining first, which adds time
- Any new wiring or spur is electrical work for a registered electrician
Every cylinder and fuse board is different. Your plumber or electrician will price the job on the part, the access and your county, so treat the figures on the right as a budgeting guide, not a quote.
- Immersion element replacement €150–300
- Cylinder thermostat replacement €90–160
- Immersion timer, supply and fit €80–200
- Dual element upgrade €200–350
- New immersion wiring or spur €120–250
- Descale and element clean call-out €90–150
Indicative ranges only. Always confirm with a written quote.
What Affects the Price of an Immersion Job
Access to the Element
A cylinder boxed into a hot press or wedged under stairs takes longer to reach and drain, which adds labour to an otherwise quick job.
Scale Build-Up
In hard-water areas a heavily scaled element or cylinder needs more work to clear and refit, and can shorten the life of the new part.
Cylinder Condition
An old or corroded cylinder may not take a new element cleanly. If the tank itself is failing, replacing the cylinder is the better spend.
Wiring at the Fuse Board
A new spur, a faulty switch or a tripping RCD is electrical work for a registered electrician, and adds to a plain element swap.
The choice
Single or Dual Element: Which Suits Your Cylinder
A single element sits low in the cylinder and heats the whole tank. It is the standard fit in most Irish homes, simple to replace and fine as an everyday backup where you are happy to wait for a full tank to warm.
A dual element cylinder has two heaters, a short one near the top for a quick boost of a few litres, and a full-length one for a complete tank. It suits larger cylinders and homes that want a fast top-up without paying to heat the whole tank each time.
On the day
How an Immersion Heater Is Replaced
A straightforward element or thermostat swap is a same-day, one to two hour job. Here is how a plumber works through it, with a registered electrician handling anything at the fuse board.
Isolate the Power and Water
The immersion is switched off and isolated at the fuse board, and the cold feed to the cylinder is turned off before any work starts.
Drain the Cylinder
Enough water is drained from the cylinder to bring the level below the element, so it can be removed without flooding the hot press.
Remove the Old Element
The wiring is disconnected, the old element or thermostat is unscrewed from the cylinder boss, and the seal is checked and cleaned.
Fit the New Part
The new element or thermostat is fitted with a fresh gasket, tightened to seal cleanly, and the cylinder is refilled and checked for leaks.
Reconnect and Test
The wiring is reconnected, and where it involves the supply or switch a registered electrician confirms it is safe before power is restored.
Set the Thermostat and Timer
The cylinder thermostat is set to a safe temperature and any timer is programmed, then the immersion is run to confirm the water heats properly.
Safety
When to Call an Electrician, Not Just a Plumber
Fitting the element or thermostat inside the cylinder is plumbing work, but the wiring that feeds it is not. A new spur, a faulty immersion switch, a burnt connection or an immersion that trips the RCD is electrical work, and that belongs with a registered electrician.
If your immersion keeps tripping the fuse board, or the switch is warm or discoloured, do not keep resetting it. Have a registered electrician check the supply, because a persistent trip is a warning, not a nuisance. Getting the right trade for each part keeps the job safe and signed off properly.
- The element and thermostat are inside the cylinder, a plumbing fit
- The supply, switch and fuse board are electrical work
- A tripping immersion needs a registered electrician, not repeated resets
Hiring
How to Choose a Plumber for an Immersion Heater
An element or thermostat swap is quick work for an experienced plumber, but the electrical side matters. A good quote is specific about the part and clear on who handles the wiring.
Name the Part on the Quote
A clear quote states whether it covers the element, the thermostat, the timer or a dual element, plus the labour. A vague quote leaves room for surprises.
Check the Electrical Side
Fitting an element is plumbing, but any work on the supply, switch or fuse board is electrical. Confirm your plumber works with a registered electrician for that part.
Ask About the Call-Out
For a small job the call-out can be a big part of the bill. Ask what is included, and whether draining a scaled cylinder is priced separately.
Confirm They Test It
A good tradesperson refills the cylinder, checks for leaks and runs the immersion before leaving, so you know the hot water works before they go.
Local coverage
Immersion Heater Replacement by County in Ireland
What you pay, how quickly a plumber can reach you, and how hard the local water is on your element all come down to where you live. Choose your county for local 2026 prices and plumbers.
Leinster
12 countiesFrom Dublin apartments running on the immersion alone to older houses across Meath, Kildare and Wicklow, element and thermostat swaps are steady work, with hard water in parts of the region wearing elements faster.
Munster
6 countiesCork, Limerick and the wider region see plenty of immersion work, from city apartments to rural homes in Kerry and west Cork where the cylinder is often the main hot water backup to an oil boiler.
Connacht
5 countiesAcross Galway, Mayo and the west, homes lean on the immersion when the oil or solid-fuel heating is off, so a reliable element and a working timer matter through the cooler months.
Common questions
Immersion Heater Questions From Irish Homeowners
How much does it cost to replace an immersion heater in Ireland in 2026?
Replacing the immersion element costs €150 to €300 supplied and fitted in 2026, including labour and VAT. A cylinder thermostat is €90 to €160, and an immersion timer is €80 to €200. A dual element upgrade runs €200 to €350.
Why is my immersion heater not heating the water?
The most common cause is a burnt-out element, which needs replacing. Other causes are a failed cylinder thermostat, a tripped fuse or RCD at the board, or a faulty timer. If it keeps tripping when switched on, have a registered electrician check the wiring.
Do I need an electrician to replace an immersion heater?
Fitting the element or thermostat inside the cylinder is plumbing work. But any work on the supply, the immersion switch or the fuse board is electrical and should be done by a registered electrician. Many plumbers work alongside one for that part of the job.
What is the difference between a single and dual element immersion?
A single element sits low in the cylinder and heats the full tank. A dual element cylinder has two heaters, a short top one for a quick boost of a few litres and a full-length one for the whole tank, so you can heat a little or a lot.
How long does it take to replace an immersion element?
A straightforward element or thermostat replacement takes one to two hours. Most of the time is spent draining the cylinder below the element, removing the old part, fitting the new one with a fresh seal, and refilling and testing for leaks.
Why does my immersion keep tripping the fuse board?
An immersion that trips the RCD or blows a fuse when switched on usually has a failed element or a wiring fault. Do not keep resetting it. A registered electrician should check the supply and switch, as a repeated trip is a safety warning.
Is it cheaper to heat water with the immersion or the boiler?
A gas or oil boiler is usually cheaper for heating a full tank, while the immersion is handy for a small top-up or when the boiler is off. Setting a timer and cylinder thermostat, or wiring the immersion to a night-rate meter, keeps the electricity cost down.
Find a Plumber for Immersion Heater Replacement
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