CE 207 on a Worcester Bosch combi usually means the water pressure in your heating system has dropped too low for the boiler to run safely, so it has locked out.
What you can safely check
- Look at the pressure gauge on the front of the boiler. With the heating off it should normally sit between 1 and 1.5 bar.
- If it's below 1 bar, you can usually top it up yourself using the filling loop. Your boiler manual shows where it is.
- Check radiators, valves and visible pipework for drips, and look at the pressure relief pipe outside for signs of water.
When to call an engineer
If the pressure keeps dropping after you top it up, there's a leak somewhere — in the system, or inside the boiler. Never remove the boiler casing yourself. Call a Gas Safe registered engineer.
Repair it, or replace it?
If your boiler is over 10 years old, compare a repair against a new combi before you pay for parts.