Managing heating and hot water Cardiff issues is an essential part of your tenancy, especially during colder months. Problems with boilers, radiators or hot water can often be resolved quickly with a few simple checks.
This guide explains what to do if you have no heating or hot water, how to troubleshoot common boiler issues, and when to report a fault.
This guide covers common heating and hot water Cardiff issues, helping tenants quickly identify and resolve problems.
Problems with heating or hot water are common in rental properties, particularly in winter or after long periods of inactivity.
In many cases, issues such as low boiler pressure, thermostat settings or power interruptions can be resolved without needing an engineer.
👉 Taking a few minutes to check these can often restore heating quickly.
Is there no heating, no hot water, low pressure or just one radiator not working? Identifying the exact issue helps resolve it faster.
Many heating and hot water Cardiff problems can be resolved with simple checks before reporting a fault.
Typical causes include low boiler pressure, power issues, thermostat settings, or air in radiators
Contact us if there is no heating or hot water after checks, or if the issue appears to be a fault with the boiler or system.
Modern boilers will often display an error code when something isn’t working correctly. These codes help identify the issue quickly and can save time when reporting a fault.
If your boiler is showing a code, make a note of it before reporting.
👉 Key point: Always include the error code when reporting — this helps diagnose the issue much faster.
If you have no heating or hot water, start by checking the basics. Make sure the boiler is switched on, has power, and that the thermostat is set high enough for the heating to come on. It’s also worth checking the timer or programmer settings, as these can sometimes be switched off or reset.
Before reporting the issue, check the boiler pressure — if it is below the normal range (usually around 1–1.5 bar), this can prevent the system from working properly. You should also look for any error codes displayed on the boiler, as these can help identify the issue quickly when reporting it.
👉 Key point: Check power, thermostat, pressure and any error codes before reporting — this helps resolve issues faster.
If your boiler is not responding or appears to have stopped working, check whether it is showing an error code or warning light. Many modern boilers display a fault code which can indicate the cause of the problem.
Try resetting the boiler using the reset button (refer to the boiler manual if needed). If the boiler continues to fail after resetting, or the same error code keeps appearing, this likely indicates a fault that needs to be reported.
👉 Key point: Always include any error codes when reporting — this helps diagnose the issue without delay.
If some radiators are cold while others are working, this is often caused by air trapped in the system or valves being closed. You can usually fix this by bleeding the radiator safely.
To bleed a radiator:
After bleeding, check your boiler pressure — it may need topping up.
👉 Key point: Cold radiators are usually caused by trapped air and can often be fixed without reporting a fault.
Not all properties have a gas boiler. Some homes use electric heating and hot water systems, which work differently.
You likely have a boiler if:
👉 Boilers heat water on demand, so you can usually have longer showers without running out.
You may have an electric system if:
✔ Check that the hot water switch is turned on
✔ Allow time for the tank to heat up (can take 30–60 minutes or more)
👉 Key point: If your hot water has run out, it may just need time to reheat.
It’s also important to know what type of heating you have:
Electric Wall Heaters
Radiators (Boiler System)
👉 Key point: If you have electric heaters, there is no boiler — each heater must be switched on individually.
Low Boiler Pressure – What To Do
Low pressure is one of the most common heating issues in Cardiff properties and can often stop your boiler from working.
Most boilers should sit between 1.0 and 1.5 bar when cold.
If the pressure is too low:
Locate the filling loop (usually under the boiler)
Slowly open the valves
Watch the pressure gauge rise
Stop when it reaches around 1–1.5 bar
Close the valves fully
⚠️ Do not overfill — this can cause further issues
👉 Key point: Low pressure is usually easy to fix, but frequent drops may indicate a leak and should be reported.
Tenants are expected to carry out basic checks such as resetting the boiler, checking pressure, and ensuring controls are set correctly.
However, you should not attempt repairs or tamper with the boiler beyond simple checks.
If you’ve tried the steps above and still have no heating or hot water:
👉 Report the issue and we’ll arrange further investigation.
If you have issues with heating, hot water or gas, the following contacts may be helpful.
If you smell gas or suspect a gas leak, leave the property immediately and call:
0800 111 999
Do not use electrical switches or open flames.
If your property has no electricity, contact your local network operator:
105
This is a free national number for power cuts.
If your heating or hot water is not working after checks, report it to our maintenance team.
If you have no water or a supply issue, contact Welsh Water:
0800 052 0145
