Worcester boiler control panel: what the buttons do and what to check

Two layers of control, and which one you are looking at

Most calls that begin "my Worcester controls have stopped working" are really a question about which box the setting lives in. The boiler on the wall has its own panel, display and keys. The unit in the hallway is a separate product with its own manual.

That split explains a lot of odd behaviour. A room control can be calling for heat perfectly while the boiler panel holds the flow temperature too low for the radiators ever to get properly hot.

This page is about the boiler's own panel. The room controls are covered elsewhere on this site: the Worcester Wave, the Bosch EasyControl CT200 and the Greenstar Comfort RF range sit on our Worcester Bosch thermostat page, with programming steps in our guide to setting a Worcester Bosch thermostat. Both are linked at the foot of this page.

Smart Plan is not affiliated with, or endorsed by, Worcester Bosch.

What the keys on a Greenstar panel do

Newer Greenstar boilers use a display and a row of soft keys. On the Greenstar 4000, Worcester's user instructions list a burner display that lights when the burner is alight, up and down keys, a back key, an ok key, a menu key, a hot water key and a heating key. Press the heating key and the set maximum flow temperature appears, adjustable between 30°C and 82°C on that model.

Pressing ok switches the hot water between Eco and Preheat. Worcester describes Preheat as keeping the hot water heat exchanger pre-heated to reduce the time taken to deliver hot water at the tap, and Eco as an energy saving feature which disables Preheat, enabled by default during the initial appliance start up. Worcester also flags a scalding risk: the appliance is supplied with the central heating control set at approximately 65°C, and above that it advises fitting a thermostatic mixing valve at the point of use.

Older Greenstar i boilers use a different panel: an analogue pressure gauge, an ECO/OK button, an Info/Return button, the display, and a Reset button that doubles as the service engineer button. Its blue light is both the heat demand indicator and the fault indicator, so it lights during a demand and flashes during a fault.

System pressure now often sits on the display rather than a dial. The Greenstar 4000 has a pressure menu reached from the Boiler status screen, showing the reading against red, yellow and green zones, so you can see at a glance whether the system is low.

Worcester boiler control panel not working: what to check

Work out which of three things you are looking at: a dead panel, a panel showing a fault, or a panel that works but leaves the house cold.

A dark panel is a power question. Check the fused spur or plug feeding the boiler is switched on. Worcester's own remedy for no blue operation light on the Greenstar i is a momentary power failure: disconnect the appliance supply, wait a few seconds, then reconnect. Never open the casing, because Worcester states that only a competent engineer can remove the appliance case.

A fault code with the blue light flashing is an alert state. Worcester's instruction is to press reset briefly once: if it worked, the appliance returns to normal operation, and if not, the code is displayed again. Where the reset sits depends on the model. The Greenstar i has a dedicated Reset button on the panel. The Greenstar 4000 has no Reset button at all: its troubleshooting section tells you to press the up and down keys until Reset is displayed. Worcester is explicit that, because of the boiler's internal safety systems, some codes cannot be cleared by a simple reset, so there is no point repeating it.

Note the whole code first. Worcester asks you to quote the alert code and the three digit number underneath it, for example EA and 227. For a flashing EA, Worcester's user fault table gives three causes: no gas supply or low gas supply pressure, a blocked condensate outlet, and a blocked flue. Checking the condensate and flue outlets from outside is a homeowner job only where it is safe to do so. The gas supply is one for your gas supplier or an engineer, never for you.

A panel that responds but does not get the house warm enough is usually a temperature or pressure problem. Worcester's user fault table has a row headed "Desired room temperature is not reached", listing radiator valves set too low, the flow temperature on the appliance set too low, a low setting on the room thermostat, air trapped in the system and low system water pressure. A boiler giving no heat at all is a different symptom: rule out a dead panel or an alert code before you start adjusting valves.

Five things worth remembering about the panel

Each one comes from Worcester Bosch's user instructions for the model named.

• The panel sets the flow temperature, not the room temperature. On the Greenstar 4000 it adjusts between 30°C and 82°C.
• Eco and Preheat for hot water sit on the boiler panel, not the thermostat, and Eco is on by default from the initial start up.
• A resettable fault gets one press of reset. Worcester says some codes cannot be cleared by a simple reset at all.
• On a Greenstar 4000 there is no Reset button: hold the up and down keys until Reset appears on the display.

When it needs an engineer

The panel is low-voltage electronics, but the appliance behind it burns gas, and that is where the line sits. Changing settings, clearing an alert with one reset and topping up the pressure per your manual are yours. Anything behind the casing is not.

One rule sits above all of it. If you smell gas, do not operate electrical switches, do not smoke or use a lighter or matches, do not use the telephone or ring doorbells inside, turn off the gas at the meter or regulator, open the windows and doors, leave the building and call the National Gas Emergency Service on 0800 111 999 from outside. That is Worcester Bosch's own instruction, and it comes before any control setting or fault code.

Short of that, if the settings look right and the panel still will not run the heating, send us the code and the three digit number under it. We work with a national network of thousands of Gas Safe registered engineers and will arrange for one to attend and diagnose it. The number is 0333 772 6247 if you would rather say it than type it.

Worcester boiler panel FAQs

Panel set right and the heating still will not run?

Send us the code and the number under it and we will arrange a Gas Safe registered engineer to attend and diagnose it. A one-off visit is Monday to Friday, 09:00 to 17:00, excluding bank holidays, is paid in advance and carries no workmanship guarantee. Cover is the other route, for the breakdown that has not happened yet, so anything the boiler is showing today is pre-existing and sits outside it. Read the limits before you buy. Cover applies only to the equipment on your cover sheet, and the boiler and central heating module excludes any repair or replacement of wifi enabled or internet based equipment, so a smart control like the Wave or the EasyControl is not covered. The general exclusions also rule out adjustments to settings, battery changes and resetting equipment. Where the module does pay, it covers parts and labour to £500 across a 12-month period on a boiler under 7 years old, or £200 if it is over 7, each a yearly ceiling across all faults combined, so a large repair can outrun it. Attendance is a target, not a promise: we aim to get an engineer out to you within two working days, with cover-plan call-outs Monday to Friday, 08:00 to 18:00. A £95 call-out fee, paid in advance, applies in your first 30 days, on faults the plan does not cover, on no-access visits and on an early annual service, and your cover still runs throughout those 30 days. The 12-month agreement period starts the first time you use a service, after a 14-day cooling-off period that ends as soon as a service is carried out. Leaving after that costs the remaining months or 75% of the outstanding balance. Smart Plan comes from UK Boiler Company Ltd, trading since 2014, and is a service plan, not insurance.

Helpful links

• Worcester Bosch thermostat not working: Wave, EasyControl and Comfort RF
• How to set a Worcester Bosch thermostat
• Worcester Bosch fault codes
• Worcester Bosch technical help
• Boiler & central heating cover
• Tell us about your boiler
• Worcester Bosch boiler user manuals
• Check an engineer on the Gas Safe Register