Low
P.02 on Vaillant Atmomax

Your boiler is currently running a special test mode at its lowest power setting to check for performance or stability.

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

Minimum load test program

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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

Wait approximately 15 minutes for the test program to finish automaticallyTurn the boiler off and back on again if you wish to cancel the testPress the 'i' button or the 'Back' button to return to the standard display

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 P.02: 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

P.00View →P.01View →P.06View →

Related guides you might find useful

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →