No hot water: what you can safely check

Does the boiler have power?

Check whether the display is lit. If it is dark, see that the plug is in the socket and that the circuit in the consumer unit has not tripped.

If the display stays dark while the power supply is fine, tracing the cause is a job for an engineer.

Are the thermostat and hot-water setting correct?

A room thermostat controls the heating, and not always the hot water. Most boilers have a separate hot-water temperature setting or an eco mode.

If the boiler is in a holiday or summer mode, hot water may be switched off. Check the user manual for your appliance.

What does the pressure gauge show?

Read the visible water pressure on the gauge or display. What counts as normal varies by appliance and system; the manufacturer's manual gives the right figure for your boiler.

If the pressure is clearly below what the manufacturer states, the boiler may shut itself down. Our article on pressure loss covers that in more detail.

Is an error code showing?

Write down the make, model and the exact code, and take a photo of the display if you can. Those details save time when we plan the visit.

No hot water, or no heating?

If the radiators warm up but the tap water stays cold, the problem usually sits in the hot-water side of the boiler.

If there is hot water but the radiators stay cold, it points more to the heating side, the thermostat or circulation.

If neither works, the boiler has most likely shut down altogether and a repair visit is needed.

When should you call an engineer?

• The error code returns after one normal reset as described in the manual.
• The display stays dark although the power supply is fine.
• You can see water under or beside the boiler.
• There is still no hot water although the settings and pressure look right.