Medium
ALL 25 on Sime Murelle HE Regular

Your boiler is having trouble communicating with the temperature sensor in your hot water storage tank, which means it cannot correctly monitor or heat your stored water.

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

solar proBE Error storagE tanK (s2)

From this model's manual
Verified against the Sime Murelle He Regular installation & service manual, page 41.
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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