BoilerFaultCodesYour heat pump's engine is drawing too much electrical power, causing the system to shut down to protect its internal circuits.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Inverter High Current
What causes this fault?
This fault occurs when the heat pump's internal power supply detects a sudden surge or excessive electrical demand from the system's moving parts. It is most commonly caused by an electrical failure within the compressor or the circuit board, where the component tries to draw more power than the system can safely handle. As a result, the unit shuts down immediately to prevent permanent damage to the sensitive electronics.
This fault is more common during the height of winter or peak summer, as the compressor has to work much harder to meet temperature demands, putting more strain on the electrical components.
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 J12 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
Affiliate links — we may earn a commission at no extra cost to you.