Faulty Electric Boiler Repair: Why It Trips, Cuts Out Or Just Stops Heating
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If you have an all electric home or flat in places like Dagenham, Rainham or the surrounding areas, there is a good chance your heating and hot water come from an electric boiler rather than gas.
Most of the calls we get sound very familiar:
“The electric boiler keeps tripping the RCD.”
“No hot water at all, but the lights and sockets are fine.”
“It works for a bit then cuts out again.”
The good news is that electric boilers are fairly simple beasts compared with modern gas boilers. The bad news is that when something does go wrong, it can take proper electrical testing to find the real fault.
In this article I will walk you through:
What an electric boiler actually is
Common faults and what they usually mean
What you can safely check yourself
When you need an electrician rather than a plumber
How we normally repair electric boiler issues for homeowners and landlords
Electric boilers 101: where and why people use them
You are most likely to see electric boilers in:
Flats and maisonettes with no gas supply
Smaller houses converted to all electric
Some off grid or ex communal heating blocks
Energy Saving Trust point out that electricity is more efficient at the point of use, but at the moment it is roughly four times more expensive per unit than gas. That means electric heating can be more expensive to run, although it can still make sense in smaller or very well insulated homes where installing gas or wet systems would be costly.
So if you already have an electric boiler, it is worth keeping it running as efficiently and reliably as possible, rather than limping on with faults that waste energy and cause constant nuisance trips.
Classic electric boiler problems we see
1. Electric boiler keeps tripping the RCD or MCB
This is probably the most common complaint.
Several technical guides and fault finding articles list the usual suspects:
Faulty heating element drawing leakage current to earth
Water ingress or internal leaks reaching live components
Damaged wiring or connectors inside the boiler
Faulty external wiring or a bad supply socket for smaller units
RCDs are there to protect people from electric shock and to reduce fire risk. Under the current BS 7671 wiring regulations, most circuits in homes, including those supplying heating, now require 30 mA RCD protection.
So if the boiler keeps tripping the RCD, that is the system shouting that something is wrong. Repeatedly resetting it without investigating the cause is not a plan.
2. No power to the boiler at all
If the display is dead and there are no lights on the boiler, it can be:
A tripped MCB in the consumer unit
A blown fuse in the local fused spur
Faulty internal electrical components
A loose or damaged supply cable
Online boiler troubleshooting guides all start by checking the supply and fuses, then move on to internal faults. Before taking the cover off, they all add the same warning: isolate the power properly or leave it to a qualified person.
3. Boiler runs but water is only lukewarm
Here we are usually looking at one or more failed elements or a control issue.
Electric boiler help guides list issues such as:
One heating element failed, so only partial output
Thermostats or sensors not reading correctly
Limescale build up on elements in hard water areas reducing efficiency
You can often hear the unit working and feel some heat in the pipes, but radiators never really get going, or hot water is only warm.
4. Boiler is noisy or has burning smells
Buzzing, sizzling or a hot plastic smell are never a good sign.
Common causes include:
Arcing or loose connections on terminals
Overheating internal wiring
Water leaks causing short circuits or tracking
Fault finding guides are very blunt here: switch off the appliance at the isolator and do not turn it back on until it has been inspected.
What you can safely check yourself
Before calling anyone out, there are a few low risk checks you can do.
Consumer unit and RCD
Check whether a breaker has tripped or an RCD has gone off.
If it has, reset it once. If it immediately trips again when the boiler tries to run, leave it off and call an electrician.
Fused spur or isolator
Many boilers have a local isolator with a fused connection unit. Check the switch is on and the fuse has not blown, if you know how to do that safely.
Programmer or timer settings
Make sure the hot water and heating times are set correctly and the clock is right. A surprising number of “boiler faults” are actually timer issues.
Room or cylinder thermostats
Turn a room stat up a few degrees to see if the boiler responds.
Make sure any cylinder stat is not set to a very low temperature.
What you should not do is start opening the boiler casing or disconnecting cables unless you are trained and know how to test and isolate properly. There is live mains voltage inside, and the combination of water and electricity makes for serious risks if you are guessing.
Landlords: you cannot ignore a faulty electric boiler
If you are a landlord with tenants in Dagenham, Rainham or anywhere else in England, the law is clear.
Government guidance and housing law explain that:
Landlords must keep the property safe and free from health hazards and must make sure heating and hot water are in proper working order.
Shelter’s legal resources confirm that landlords are responsible for fixing most problems with heating, hot water and power in rented homes, including a broken boiler or unsafe electrics.
So a tripping RCD, no hot water or no heating from an electric boiler is not something that can sit for weeks while tenants shiver. You are expected to arrange repairs in a reasonable timeframe and to use competent people to do the work.
This is also where regular EICR testing and general electrical maintenance can help. If we pick up issues in advance, you are less likely to face emergency breakdowns in the middle of winter.
Why RCD tripping on an electric boiler is serious
RCDs trip when they detect leakage to earth above a small threshold, typically 30 mA in domestic settings.
With electric boilers there are a few extra risk factors:
Heating elements can absorb tiny amounts of moisture when cold, causing leakage when first energised. Properly designed systems allow for this, but worn or damaged elements can leak enough current to trip an RCD.
Internal leaks can allow water to reach live parts, which is both an electrical and a safety hazard.
Old or poorly installed wiring can overheat or crack, leading to fault currents that RCDs are designed to catch.
RCD protection is a key safety measure in modern wiring. BS 7671 and related guidance now expect almost all domestic circuits, including those feeding fixed appliances in many cases, to have RCD protection.
If your electric boiler repeatedly causes an RCD to trip, that is a strong sign that something is wrong either inside the boiler, in associated controls, or in the supply circuit. Resetting again and again without fault finding is not safe.
How Volt East usually diagnose a faulty electric boiler
When we get called to an electric boiler fault in or around Dagenham and Rainham, we treat it like any other serious electrical issue.
1. Talk and inspect
We start by asking:
What exactly happens when you try to run heating or hot water
When the problem started and whether any work was done recently
Whether it trips instantly or after a delay
Then we visually inspect:
The consumer unit and RCDs
The boiler isolator, supply cable and any external wiring
Signs of water leaks, overheating or damage around the boiler
2. Test the supply circuit
Before blaming the boiler, we test the incoming circuit:
Continuity, polarity and earth loop impedance
Insulation resistance to check for cable damage
RCD operation to ensure it is functioning correctly
This uses the same test instruments and approach we use for EICR work, which is one reason we often combine boiler fault finding with a wider electrical health check if the property has other issues.
3. Test the boiler itself
With the supply safely isolated and covers removed, we can:
Measure resistance and insulation of each heating element
Check wiring and terminal condition inside the boiler
Inspect sensors, thermostats and internal links
Fault finding guides list failed elements, water ingress and degraded wiring as the most common causes of RCD tripping and no heat in electric boilers, and that matches what we see in real homes.
At this stage we can usually tell you clearly whether it is:
Economic to repair with new parts
More sensible to replace the boiler, especially if it is very old or corroded
4. Repair, replace or rewire as agreed
If it is repairable, we:
Replace faulty elements or internal wiring as needed
Make any improvements to the local isolator or circuit required for safety
Test and document the work in line with BS 7671
If the boiler really is at the end of its life, we will say so. There is no point spending good money on parts for a unit that is likely to fail again soon.
Where needed, we can also coordinate with heating engineers if there are plumbing or cylinder issues that sit outside the electrical side.
Linking your boiler repair into wider electrical safety
A faulty electric boiler is sometimes the visible tip of a wider electrical iceberg.
In older flats and houses around Dagenham, Rainham and nearby areas, it is not unusual to find:
Old consumer units with very limited RCD protection
Overloaded circuits feeding heating and general sockets
DIY alterations around immersion heaters and time switches
Repairing the boiler without addressing those issues is a short term fix.
That is why we often recommend pairing boiler work with:
An EICR if one has not been done for some years
Any required consumer unit upgrades or remedial work as part of a wider lighting and electrical installation.
If you are also considering changing how you control heating, smart stats and timers come into play too, which ties into our home automation work.
We have separate articles that go deeper into electric radiators, underfloor heating wiring and boiler controls, and your web team can cross link those posts from this one so readers can explore all the options.
FAQs: Faulty electric boilers and repairs
Is an electric boiler safer than a gas boiler?
You do not have combustion, flues or gas leaks to worry about, which removes some risks. But you still have high power electrical elements and water in the same box. Electric heating advice from organisations like Energy Saving Trust stresses that all heating systems should be installed and maintained correctly and that electricity is still dangerous if wiring or protection is not up to standard.
My electric boiler trips the RCD once a day, but it usually resets. Can I just keep resetting it?
No. RCD trips on a boiler are often caused by faulty elements, water ingress or degraded wiring. Expert fault finding articles explicitly warn that you should not keep resetting without investigation because there is a risk of electric shock or fire.
It needs checking by a competent electrician.
As a landlord, how quickly do I have to fix a broken electric boiler?
Housing guidance says landlords must fix most heating and hot water faults within a reasonable time and that tenants are entitled to a safe, habitable home. Shelter’s legal pages and government advice both confirm that broken boilers and unsafe electrics are the landlord’s responsibility to repair.
Leaving tenants without proper heat or hot water can lead to enforcement action.
Are electric boilers very expensive to run?
Per unit of energy, yes. Current advice notes that electricity is around four times more expensive per kWh than gas on typical tariffs, although electric systems are highly efficient at the point of use.
In small, well insulated properties they can still be practical, especially if combined with good controls and, where possible, off peak tariffs or solar.
Do I call a plumber or an electrician for an electric boiler fault?
If the problem is clearly electrical - tripping RCDs, dead displays, blown fuses - an electrician is usually the first call. If there are leaks, pressure issues or cylinder problems, a heating engineer gets involved too. In practice, for many faults we handle the electrical side and coordinate with heating specialists where plumbing work is needed.
If your electric boiler in Dagenham, Rainham or nearby keeps tripping, cutting out or simply refuses to heat anything, you do not need to live with it or keep guessing.
Volt East can:
Test the supply and boiler safely
Find the real cause of the fault
Repair or advise on replacement
Make sure everything meets current electrical safety standards
A proper diagnosis now is almost always cheaper and safer than nursing a failing boiler through another winter.