Low
S.14 on Vaillant ecoMAX 635

Your boiler is currently working correctly and is providing heat to your hot water tank as intended.

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

Burner ignited (hot water operation)

From this model's manual
Verified against the Vaillant/Vaillant Ecomax 613 installation & service manual, page 45.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This is a normal status message indicating that your boiler has successfully lit the burner to heat the water in your cylinder. It shows that the system is operating exactly as it should be to provide you with hot water. No physical fault has occurred, and the boiler is simply confirming its current task.

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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.14: 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

S.24View →

All 88 fault codes on the ecoMAX 635

Seeing a different code? Every code this model can display, in one place.

d.0d.1d.2d.5d.7d.8d.10d.11d.13d.14d.16d.22d.23d.24d.25d.34d.35d.40d.41d.44d.46d.47d.60d.61d.67d.68d.69d.71d.72d.73d.80d.81d.82d.83F.0F.1F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.60F.61F.62F.63F.64F.65F.67P.1P.2P.5S.0S.1S.2S.3S.4S.5S.6S.7S.8S.10S.11S.13S.16S.17S.20S.21S.23S.24S.26S.27S.28S.30S.32S.34S.36S.37S.39S.53S.54

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

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 →