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Boiler Repairs

No heating, no hot water, low pressure, leaks or a boiler fault code? Our Gas Safe registered engineers can diagnose the problem and explain the repair options clearly.

 

Boiler Problems & Repair Help

Find common boiler faults, safe checks you can make and guidance on when to book a Gas Safe registered engineer.

BOILER PROBLEM FINDER

What’s Wrong With Your Boiler?

Choose the symptom that best matches what is happening. You’ll get a quick answer, possible causes, safe checks and guidance on when to call an engineer.

+ Tap a problem to open
01 Why Is My Boiler Not Heating My Home? The boiler is on but the property is staying cold
QUICK ANSWER

If your boiler is running but your home is not heating, the problem may be with the thermostat, heating controls, boiler pressure, circulation or a fault within the boiler or central heating system.

Possible causes

  • Thermostat or programmer settings
  • Low boiler or system pressure
  • Boiler lockout or fault
  • Heating circulation problem
  • Control or zone issue

Safe checks you can make

  • Check that the thermostat is calling for heat
  • Make sure the heating timer or programme is on
  • Look for a boiler fault or error code
  • Check the pressure shown on the boiler
  • See whether all radiators or only certain rooms are affected
WHEN TO GET HELPHeating still not working?

If the controls appear correct but the heating still does not work, arrange an engineer visit so the boiler and heating system can be properly diagnosed.

Book Heating Repair →
02 Why Is My Boiler Not Giving Me Hot Water? Heating may work but the taps are staying cold
QUICK ANSWER

No hot water can be caused by a boiler fault, a controls problem or an issue affecting how the boiler or heating system produces hot water.

Possible causes

  • Boiler fault or lockout
  • Hot-water controls problem
  • Sensor or internal component issue
  • System-specific hot-water fault

Safe checks you can make

  • Check that the boiler has power
  • Look for a fault or error code
  • Check normal hot-water controls
  • Try more than one hot-water outlet
  • Note whether the central heating still works
WHEN TO GET HELPStill have no hot water?

If hot water does not return after normal user checks, arrange a boiler diagnosis rather than repeatedly resetting the appliance.

Book an Engineer →
03 Why Does My Boiler Keep Losing Pressure? The pressure keeps dropping or needs regular topping up
QUICK ANSWER

Repeated boiler pressure loss usually means the heating system is losing pressure somewhere. A visible or hidden leak, boiler component or pressure-control issue may be responsible.

Possible causes

  • Heating-system leak
  • Radiator valve or pipework leak
  • Boiler-side fault
  • Expansion or pressure-control problem

Safe checks you can make

  • Check the pressure shown on the boiler
  • Look for visible water around accessible radiators
  • Check accessible valves and pipework
  • Look underneath the boiler without removing covers
  • Note how quickly the pressure drops
WHEN TO GET HELPPressure keeps falling?

If the pressure repeatedly drops, arrange an inspection rather than continually topping up the system without identifying the cause.

Diagnose Pressure Loss →
04 What Does My Boiler Fault Code Mean? An error number or warning is showing on the boiler
QUICK ANSWER

A boiler fault code identifies an abnormal condition detected by the appliance. The exact meaning depends on the boiler manufacturer and model.

Possible causes

  • Ignition or flame issue
  • Pressure or circulation problem
  • Sensor or control fault
  • Manufacturer-specific appliance fault

What you can safely do

  • Write down the exact fault code
  • Check the manufacturer’s user instructions
  • Note what happened before the fault appeared
  • Only use a normal user reset if the manual permits it
  • Never remove the boiler casing
WHEN TO GET HELPFault code keeps returning?

Tell us the boiler make, model and exact fault code when booking. That gives the engineer useful information before the visit.

Report a Boiler Fault →
05 Why Is My Boiler Leaking Water? Water or dampness is visible near the boiler
QUICK ANSWER

Water around a boiler may come from the appliance, a nearby valve, pipework or another part of the heating system. The source should be identified rather than assumed.

Possible causes

  • Boiler component leak
  • Valve or connection leak
  • Pressure-related discharge
  • Nearby heating pipework leak

Safe checks you can make

  • Look for the visible source without removing covers
  • Check whether boiler pressure has changed
  • Check accessible nearby pipework
  • Keep water away from electrical equipment
  • Do not remove the boiler casing
WHEN TO GET HELPBoiler still leaking?

A persistent or worsening leak should be professionally assessed, particularly when it is affecting boiler operation or is near electrical equipment.

Report a Boiler Leak →
06 Why Is My Boiler Making Strange Noises? Banging, whistling, vibrating or gurgling sounds
QUICK ANSWER

New or unusual boiler noises can be associated with circulation, trapped air, system pressure or a component that requires further investigation.

Possible causes

  • Air within the heating system
  • Circulation problem
  • Pressure issue
  • Component vibration or wear

Useful checks

  • Note whether the sound is banging, whistling or gurgling
  • Note when the sound occurs
  • Check the boiler pressure
  • See whether radiators heat evenly
  • Note whether the sound is getting worse
WHEN TO GET HELPNoise continuing?

Persistent or worsening boiler noises should be investigated, particularly when they occur alongside heating, hot-water or pressure problems.

Arrange an Inspection →
07 Why Are My Radiators Not Heating Properly? One or more radiators are cold or heating unevenly
QUICK ANSWER

Cold or uneven radiators can be caused by radiator valves, trapped air, circulation problems, system pressure or restrictions within the heating system.

Possible causes

  • Closed or stuck radiator valve
  • Trapped air
  • Heating circulation problem
  • System balancing issue
  • Deposits or restriction within the system

Safe checks you can make

  • Check whether all radiators are affected
  • Make sure radiator valves are open
  • Check your thermostat and heating controls
  • Check the boiler pressure
  • Note whether the radiator is cold at the top or bottom
WHEN TO GET HELPRadiators still cold?

If radiators continue to heat poorly or unevenly, the central heating system may need further diagnosis.

Book Heating Repair →
08 Why Does My Boiler Keep Switching Off? The boiler starts but repeatedly stops or locks out
QUICK ANSWER

A boiler that repeatedly switches off may be experiencing a pressure, circulation, controls or appliance fault that causes it to stop normal operation.

Possible causes

  • Recurring boiler lockout
  • System pressure issue
  • Heating control problem
  • Circulation fault
  • Boiler component fault

Safe checks you can make

  • Look for a boiler fault code
  • Check the boiler pressure
  • Check your normal heating controls
  • Note when the boiler switches off
  • Avoid repeatedly resetting the same persistent fault
WHEN TO GET HELPRepeated lockouts?

If the boiler repeatedly switches off or displays the same fault, arrange an engineer visit to identify the underlying cause.

Book Boiler Diagnosis →
HELP US UNDERSTAND THE FAULT

Useful details when you book

You do not need to diagnose the boiler yourself. A few simple details can give the engineer a clearer starting point.

01 Boiler make and model
02 Exact fault code
03 Current pressure reading
04 When the problem started
WHAT HAPPENS NEXT

From fault to next step

The aim is to make the repair process clear from the moment you report the problem.

1
Tell us what’s happening Give us the symptoms, fault code and any useful appliance details.
2
Engineer assessment The boiler and relevant parts of the heating system are checked to identify the likely cause.
3
Understand the next step We explain what has been found and the appropriate repair or service route.
Gas safety comes first

Never remove a boiler casing or attempt work on gas components yourself. If you smell gas or suspect a gas leak, call the National Gas Emergency Service on 0800 111 999. If there is an immediate threat to life or property, call 999 or 112.

CAN’T FIND YOUR EXACT PROBLEM?

Tell us what’s happening

Describe the symptoms in your own words and include any fault code, boiler details or useful information you have. You do not need to diagnose the problem yourself.

Report an Issue

Annual Boiler Service

Stay on top of annual servicing. Regular servicing can help meet manufacturer servicing requirements and keep your boiler properly maintained.

From £75

Boiler Repair

No heating, no hot water, or a boiler fault code? We’ll diagnose the problem and explain the repair options clearly.

From £120

Loved by homeowners

Don't just take our word for it

Real feedback from customers who have used Let’s Heat for heating and cooling services.

Really straightforward from the first enquiry through to installation. Everything was explained clearly and the work was left tidy.

J

James

Cardiff

Good communication throughout and helpful advice when choosing the replacement boiler. The installation went smoothly.

S

Sarah

Newport

Booked a boiler service and the engineer explained what had been checked and what to keep an eye on. Very helpful.

D

Daniel

Bristol

Quick response when our boiler developed a fault. The problem was explained clearly and we knew what the options were.

E

Emma

Bridgend

The air conditioning installation was neat and the system was explained properly before the engineer left.

M

Michael

Swansea

Friendly, clear and easy to deal with. We were kept updated and knew what was happening at each stage.

S

Sophie

Chepstow

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Boiler support for every stage

Get help with a boiler fault

Arrange professional fault diagnosis when your boiler stops working properly or your heating and hot water are affected.

Gas Safe registered engineers

Boiler installation, servicing and repairs carried out by Gas Safe registered engineers.

Warranty and aftercare

Clear handover, warranty information and support after your new boiler installation.

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Spread the cost of your new boiler with available finance options, subject to status and lender approval.

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Is it time to replace your old boiler?

Explore modern boiler options for your home and get straightforward guidance on boiler type, size, controls and installation.

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Vaillant

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Ideal

Viessmann

Areas We Cover

Boiler Repairs Across South Wales & Bristol

Let’s Heat provides boiler repairs and fault diagnosis across Cardiff, Newport, Bristol and surrounding South Wales and South West areas. Check availability for your postcode when booking.

How to Report an Issue

If you have a problem with your boiler, heating, gas or air conditioning, you can report the issue using one of the options below.

Call Us

Speak to our team about the issue and tell us what is happening. We can then advise you on the next step or arrange an appointment where appropriate.

Email Us

Send us details of the issue, including any fault codes or useful information about the appliance or system.

Report an Issue Online

Complete our online form with a few details about the problem, your property and the service you need.