What to check, in order
- Check the pressure gauge
Baxi says it should read between 1 and 2 bar. If it's below 1 bar, top it up with the filling loop.
- Reset the lockout
On boilers with a selector switch, turn it to R and hold it there for at least 5 seconds, then let go. If yours has a reset button, press it until the red light goes out. On boilers reset with the temperature control knob, turn it fully anticlockwise, hold it until the red lockout light goes out, then turn it back to your setting.
When to call a Gas Safe engineer
If the code comes back, call a Gas Safe registered engineer to find what's stopping the water.
A repair visit will usually check the pump, the flow of water round the system and the overheat thermostat.
- Note the model and serial number. They're on a label on the data badge, usually under the boiler or behind the front cover.
- Write down the exact code, and what the appliance was doing when it appeared.
- Check whether it's still under warranty. If it is, the repair may cost you nothing.
Quick answers
What does the Baxi E125 fault code mean?
Baxi lists E125 as a water circulation fault. The boiler has stopped because water isn't moving through it as it should.
Can I fix Baxi E125 myself?
Engineer only (about 10 minutes to check and reset). Start with: check the pressure gauge; reset the lockout. If the code comes back, call a Gas Safe registered engineer to find what's stopping the water.
Is Baxi E125 worth repairing?
Get a quote first. If a reset doesn't clear it, the cost depends on what an engineer finds. Ask for a price before the work starts.
Checked against
- Baxi: boiler error codes (list for engineers)
- Baxi: what should my boiler pressure be set at
- Baxi: how to reset a Baxi boiler
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.