Medium
Er.13 on Vaillant Turbomax Pro 28 2E

Your boiler is struggling to switch between heating your radiators and heating your hot water taps, which may cause your hot water to stop working or your radiators to get hot when they shouldn't.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Diverter valve

From this model's manual
Verified against the Vaillant Turbomax Pro 28 2e 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.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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