BoilerFaultCodesYour solar heating system has stopped working properly because either air is trapped in the pipes or the circulation pump has become stuck.
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: Solar pump jammed or air in system / Air in solar thermal system.
What causes this fault?
This fault occurs when the fluid in your solar heating system stops circulating correctly, meaning heat from your roof panels can't reach your water cylinder. The most common reasons are air bubbles trapped in the pipework blocking the flow or the pump itself becoming physically stuck after a period of inactivity.
This fault is frequently seen in early spring or summer when the solar system is first expected to work harder after sitting idle during the darker winter months.
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 Fault 50 126 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.