How much does it cost to fix Ariston error code 40 ●, 50 ●, red ●?

Typical repair cost for the Ariston 40 ●, 50 ●, red ● fault is £120-250 including labour.

40 ●, 50 ●, red ● High

Ariston 40 ●, 50 ●, red ● Fault Code

Q: What does the Ariston 40 ●, 50 ●, red ● fault code mean?

Your boiler is struggling to pump water around your heating system, usually because there is not enough water in the pipes or a blockage is preventing the flow.

Also written as 4050RED — same fault.

The Ariston 40 ●, 50 ●, red ● fault code means: your boiler is struggling to pump water around your heating system, usually because there is not enough water in the pipes or a blockage is preventing the flow.. It appears on 1 Ariston model in our database.

Technical description: Insufficient circulation

Typical repair cost £120-250 (including labour)

DIY fix possible

Check your boiler pressure gauge; if it is below 1 bar, use the filling loop to top it up to roughly 1.5 barCheck that all your radiator valves are fully openRestart the boiler using the reset button

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Ariston models that show the 40 ●, 50 ●, red ● fault code

Click a model for the full fault code list and model-specific repair notes.

Clas One Repair: £120-250

Source

Ariston 40 ●, 50 ●, red ● fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026