BoilerFaultCodes.com
Fd Low Lockout

Your boiler has stopped because the reset button was held down for too long or pressed by mistake, causing a minor software confusion.

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.

Technical description: Reset button pressed by mistake.

What causes this fault?

This fault occurs when the boiler's control board detects that the reset button has been held down for more than 15 seconds. It is usually caused by a user accidentally leaning on the button or pressing it for too long while trying to clear a previous error. This puts the software into a temporary state of confusion, causing it to shut down as a safety precaution.

Typical repair cost £0 (including labour)

DIY fix possible

Press the reset button briefly (less than one second).Wait for the display to clear and the boiler to restart.Ensure no other fault codes are appearing once the 'Fd' clears.

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 Fd — 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.

Worcester Bosch RD 532i RD 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