Medium
S.041 on Vaillant ecoTEC Plus 836

Your boiler has detected that the water pressure inside your heating system is currently too high, which may cause it to stop working to protect itself.

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

Thewaterpressureintheheatingsystemistoohigh.

From this model's manual
Verified against the Vaillant Ecotec Plus installation & service manual, page 79.
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 a radiator in your home that has a bleed valve.Place a cloth and a container underneath the valve.Use a radiator key to slowly release a small amount of water until the pressure gauge on the boiler drops back into the green zone (typically 1.0 to 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.041: 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 →