Low
P.05 on Heatline Monza

Your boiler is currently refilling its internal water system, which is a normal process that should resolve itself automatically.

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

Filling the appliance

From this model's manual
Verified against the Heatline Monza installation & service manual, page 27.
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 5-10 minutes for the boiler to complete the automatic filling cycle.Ensure your heating system pressure gauge is reading between 1.0 and 1.5 bar.If the code persists after 30 minutes, switch the boiler off and back on at the fused spur to reset it.

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.05: 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.01View →P.02View →

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Low pressure — repressurise guide

Step-by-step using the filling loop.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →