BoilerFaultCodesYour boiler is not receiving enough electrical power from your home's mains supply to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Power supply <170V
What causes this fault?
This fault occurs when the electrical supply entering your boiler drops to a level that is too low for the internal components to function. It is usually caused by a wider problem with the local power grid or a fault within your home's electrical wiring that prevents the boiler from receiving a steady 230V flow. In some cases, it can also mean the boiler's internal control board is failing to correctly process the incoming power.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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 17 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm 30ci 30si 35ci 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.
Affiliate links — we may earn a commission at no extra cost to you.