ACV · Prestige Solo and Excellence MkIII condensing boiler · United Kingdom and Europe

E46 error code

ACV Prestige MkIII E46 error code – NTC5 open circuit

FaultUnknownAlso: Prestige MkIII; Prestige Solo; Prestige Excellence2 min read
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Quick answer

What does ACV Prestige Solo and Excellence MkIII condensing boiler E46 mean?

ACV documents E46 for the Prestige Solo and Excellence MkIII range as: NTC5 open circuit.

The code identifies the condition detected by the product; it does not always identify the failed component on its own. Confirm the full code and exact model before ordering parts or attempting a reset.

The ACV Prestige Solo and Excellence MkIII condensing boiler E46 error code indicates aCV documents E46 for the Prestige Solo and Excellence MkIII range as: NTC5 open circuit. This guide explains what the code means, the symptoms and likely causes, the checks that are safe to make, and when to stop and arrange an authorised repair.

Symptoms you may notice

The Prestige controller displays E46. The boiler may lock out, stop firing or restrict normal heating and hot-water operation.

Common causes

The official ESYS fault table associates E46 with ntc5 open circuit. The exact wiring, sensor, combustion, pressure or controller condition must be confirmed on the appliance.

Before you start troubleshooting

Use the display, rating label or product menu to confirm the exact model. Similar-looking codes can have different meanings across product generations and regions.

  • Record the complete code before switching the equipment off.
  • Check only user-accessible controls, filters and external connections described in the manual.
  • Do not open gas, refrigerant, combustion or electrical compartments.

Troubleshooting steps

Record E46 and the exact Prestige model. Check only visible pressure, power, controls and external conditions allowed by the user instructions. Internal measurements and component checks require an approved engineer.

Can you fix this error code yourself?

The safest next step depends on the exact model and the cause behind the code. External checks may help, but a returning fault needs professional diagnosis.

A successful reset is not proof that the underlying issue is fixed. If E46 reappears, note when it happens and give that information to the service engineer.

Reset instructions

Use the ESYS reset only as described in the official ACV instructions. If E46 returns, stop resetting and contact an approved installer.

Applicable products and models

ACV Prestige Solo and Excellence MkIII condensing boiler Prestige Solo 18 MkIII; Prestige Solo 32 MkIII; Prestige Excellence 18 MkIII; Prestige Excellence 32 MkIIIPrestige Solo and Excellence MkIII condensing boilerPrestige Solo 18 MkIII; Prestige Solo 32 MkIII; Prestige Excellence 18 MkIII; Prestige Excellence 32 MkIIIManual 664Y4200 revision H, March 2011

When to contact a professional

Contact ACV support or an approved heating engineer when E46 persists, returns after a permitted reset, or requires internal testing or component replacement.

Frequently asked questions

What does ACV Prestige Solo and Excellence MkIII condensing boiler E46 mean?

ACV documents E46 for the Prestige Solo and Excellence MkIII range as: NTC5 open circuit.

Can I fix ACV Prestige Solo and Excellence MkIII condensing boiler E46 myself?

Some external checks may be suitable for the user, but the result depends on the exact model and cause. Use the official manual and arrange service if the code returns.

Should I reset the product after code E46?

Use the ESYS reset only as described in the official ACV instructions. If E46 returns, stop resetting and contact an approved installer.

When should I arrange a repair?

Contact ACV support or an approved heating engineer when E46 persists, returns after a permitted reset, or requires internal testing or component replacement.