Boiler repairs · Worcester Bosch
Worcester Bosch Boiler Repair: An Engineer Out Day or Night
Worcester Bosch boiler repair starts with an engineer at the boiler: out any hour for the £60 call-out, testing gas pressure, the electrode, the condensate siphon and the fan, and agreeing the repair price with you before any work starts. If yours is not working, a low-pressure or frozen-condensate lockout is often one you can clear yourself.
What the visit covers
- Greenstar fault codes, including EA 227, 1017, C6 and E9
- Ignition and flame detection faults: electrode, gas valve and flue checks
- Condensate siphon and trap blockages
- Pressure faults: leaks, expansion vessel and pressure sensor
- Diverter valve, pump, fan and PCB replacement
Why is my Worcester boiler not working?
On most Greenstar models a flashing blue light or a flashing display means the boiler has locked out and stored a fault code. The code is the quickest route to the cause, so read it before you do anything else.
The codes people see most often fall into a few groups. Our Worcester Bosch fault codes guide covers the rest one by one.
- EA 227: no flame detected after several ignition attempts. In cold weather this is usually a frozen condensate pipe; in mild weather it points at the gas supply, the electrode or the gas valve.
- 1017 (CE 207 on some models): water pressure too low. Top up to between 1 and 1.5 bar using the filling loop.
- C6: the fan is not reaching the speed the boiler expects. That is the fan, its wiring or the flue, and none of it is a householder fix.
- E9: the safety temperature limiter has tripped because the boiler overheated. Do not keep resetting this one.
If you can smell gas, open windows, shut off the gas at the meter if safe, keep away from switches, then leave and call the National Gas Emergency Service on 0800 111 999. Do not reset the boiler or operate switches.
Safe checks before you book an engineer
Press the reset button (some models want it held for a few seconds), or on dial models turn the dial to the reset symbol and back. Do this once. If the same code returns, a second reset rarely helps.
Check the gauge. If it is below 1 bar, find the filling loop under the boiler. Some older Greenstar models use a removable filling key rather than a braided hose; our guide to raising Worcester pressure without the key explains the options.
In a frost, trace the white plastic condensate pipe outside and pour warm, not boiling, water along it until it runs clear. Then reset. For a boiler that shows no lights at all, check the fused spur and read why a Worcester boiler will not fire up.
Nothing inside the casing is a householder job. The condensate siphon, electrode and gas valve all sit inside it.
What our engineer checks on a Worcester Bosch
For an EA 227 lockout the engineer measures working gas pressure at the valve, checks the electrode and its lead, and removes and cleans the condensate siphon, which can block with sludge and stop the boiler even when the outside pipe is clear. For pressure faults they check the expansion vessel charge and look for the leak rather than just refilling. Gas work is carried out by Gas Safe registered engineers.
Hot water failing while the radiators work, or the reverse, is usually the diverter valve on a combi. A boiler that runs for a minute and cuts out often has a circulation problem such as a seized pump or a blocked plate heat exchanger. Our no hot water repair page covers that side in more depth.
What a Worcester repair usually costs
On the wider UK market, a replacement electrode or sensor is usually a small part costing tens of pounds. A diverter valve, pump or fan tends to run into the low hundreds, and a main control board is typically the dearest part to replace.
You pay the £60 call-out for the visit, and the repair price is agreed with you on site before any work starts. Worcester Bosch offers long guarantees on many Greenstar models when they are registered, so check your paperwork. If the boiler is still covered, the manufacturer may repair it at no charge. For an older boiler, see our guide on whether to repair or replace a broken boiler.
How the visit works
Read us the display
The code, whether the blue light is flashing and what the pressure gauge says.
Fault-finding at the boiler
Gas pressure, flame signal, condensate route and flue are checked in that order for ignition codes.
Price before work
You are told the fault and the repair price, and nothing starts until you agree.
Run and test
Heating and hot water are both proven before the engineer leaves.
Worcester Bosch fault codes we fix
Questions people ask
Why is my Worcester boiler flashing blue?
A flashing blue light on most Greenstar boilers means it has locked out with a fault. Look at the display for the code. Low pressure and a frozen condensate pipe are the two you can usually clear yourself.
How do I reset a Worcester Bosch boiler?
Press the reset button, holding it for a few seconds if a quick press does nothing, or turn the selector dial to the reset position and back on dial models. The exact method is in your user manual. Reset once. If the code returns, the cause is still there and the boiler needs looking at.
Can a Worcester boiler work with low pressure?
Not for long. Once the pressure falls well below 1 bar the boiler locks out with a low-pressure code to protect the pump and heat exchanger. Topping up to 1 to 1.5 bar with the heating cold usually brings it back. If you have to top up again within weeks, there is a leak to find.
Is E9 on a Worcester dangerous?
E9 means the boiler got too hot and the safety limiter cut it out. That is the safety system working. The cause, often poor circulation, a failed pump or a sensor fault, must be found before the boiler is run again.
Do you repair Worcester boilers at weekends?
Yes, 24/7, including nights and bank holidays, across London and everywhere inside the M25. The call-out is £60 at any hour.