Low
A 04 on Vokera Verve

Your boiler is currently performing a brief automatic system check to ensure everything is initialized correctly before starting up.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

System loading

From this model's manual
Verified against the Vokera Verve installation & service manual, page 6.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check your boiler's pressure gauge and ensure it is between 1 and 1.5 barIf the pressure is low, use the filling loop to top up the system until it reaches the green zoneOnce the pressure is correct, turn the boiler off and back on again to reset the system

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like A 04: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

A 01View →A 02View →

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →