BoilerFaultCodes.com
YELLOW LED Solid Medium Information

Your boiler has entered a test mode and is currently unable to provide normal heating or hot water.

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.

Technical description: Check JP1

What causes this fault?

This fault occurs when the boiler has been accidentally switched into 'Combustion Analysis' or 'Service' mode. The most common reason is that the control selector knob was turned too far or left in a specific position meant only for engineers to test the gas levels. While in this state, the boiler ignores your thermostat and hot water taps to run at a fixed output for testing purposes.

Typical repair cost £60-120 (including labour)

DIY fix possible

Locate the selector dial on the front control panel.Turn the dial to the 'OFF/RESET' position.Wait five seconds, then turn the dial back to your desired 'Heating and Hot Water' setting.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Protect yourself from future repair bills

A boiler cover plan would cover faults like YELLOW LED Solid — no call-out fees, no surprises.

Top rated
OpenFix
Boiler & heating care plans
Get a quote →
Hometree
from £12.95/month
Get a quote →
HomeServe
from £8.00/month
Get a quote →

Affiliate links — we may earn a commission at no extra cost to you.

Vokera Rain is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

UK's #1 online installer
Boxt
Fixed-price online quotes. Next-day installation.
Get a free quote →
Heatable
Instant online boiler quotes from £1,499.
Get a free quote →
iHeat
Fast installation. Price match guarantee.
Get a free quote →

Affiliate links — we may earn a commission at no extra cost to you.

Related fault codes