Medium
S.41 on Vaillant ecoTEC Pro 30

Your boiler has detected that the water pressure inside the system is getting too high, which may cause a safety relief valve to drip or open.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Water pressure > 2.8 bar

From this model's manual
Verified against the Vaillant Ecotec Pro 30 installation & service manual, page 35.
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

Locate your radiators and find a radiator bleed valve with a square nut.Place a cloth and a container underneath the valve.Open the bleed valve slowly to release a small amount of water until the pressure gauge on the front of the boiler drops to between 1.0 and 1.5 bar.

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 S.41: 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

F.22View →F.73View →F.75View →

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

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 →