BoilerFaultCodesYour boiler has stopped working because it isn't receiving enough electricity from your home's power supply to run safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Mains supply voltage < 180V – may be a problem with your power supply
What causes this fault?
This fault occurs when the electrical voltage entering the boiler drops below a safe operating level of 180V. The most common reason is a fluctuation or brownout in the local regional power grid, though it can occasionally be caused by a fault within the boiler's internal control board after a power surge.
This fault is slightly more common during winter or extreme heatwaves when the national grid is under heavy load, causing temporary dips in local supply voltage.
DIY fix possible
Check if other appliances in your home are flickering or underperformingEnsure your fuse box / consumer unit has not partially trippedContact your electricity network provider to see if there is a brownout or power fluctuation in your area
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 E34 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Keston C36 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.