Medium
Blocking Error on Potterton Envoy 30

Your boiler has temporarily paused its operation because it has detected a minor inconsistency in its internal readings, such as water pressure or temperature.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Control Status: Blocking Error (Failure to carry out a step or malfunctioning component)

From this model's manual
Verified against the Potterton Envoy 30 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler's internal sensors detect a reading that is slightly outside of the normal operating range, leading the system to pause for safety. This is most commonly caused by a drop in system water pressure or a temperature sensor that is beginning to provide inconsistent data to the control board.

This issue is more frequent in autumn when the heating is turned on for the first time after summer, as stagnant water and settled debris can affect sensor accuracy.

DIY fix possible

Check the central heating pressure gauge is between 1.0 and 1.5 barTurn the power switch to the boiler off and back on again after 30 secondsCheck that all radiator valves are open and not blocked

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