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Worcester Greenstar Ri Troubleshooting [Common Problems & Fixes]

With most Worcester boilers, faults are few and far in between. However, even the best models from this venerable manufacturer occasionally succumb to the ills that plague all boilers.

Worry not, though; if your Worcester Ri is giving you a hard time, you’re in the right place. We’ve done lots of research and put together this Worcester Greenstar Ri troubleshooting guide, which will cover some of the most common problems with this range and walk you through possible fixes.

Worcester Bosch Greenstar Ri Troubleshooting

But, if you have consistent breakdowns and are sinking tonnes of cash into your old boiler, it might be time to consider a replacement. The cheapest place to get a Worcester boiler fitted is Heatable. They’ve partnered with all the major brands, including Worcester Bosch, and provide the industry’s best boiler prices. Get a fixed price (no personal details needed) on an installation using their boiler calculator.

Heatable boiler installations

Alternatively, keep reading, and we’ll try offer a few explanations for why you’re seeing certain error codes, the boiler problems they represent, and what to do next.

*Note. Do not attempt to fix your boiler: Speak to a Gas Safe registered repair company instead.

No Green Light: Burner on Indicator

The green light on a Worcester Ri indicates the burner is operating. We’ve been called out to various Worcester Bosch boiler models, with problems where the green light was off but the boiler was working correctly.

RELATED READING: Read our review of the Worcester Bosch CDi Classic combi boiler here.

Whether your Worcester boiler has its green light flashing, or it’s off completely, there are 2 possible explanations:

Explanation 1: LED Failure

The most obvious explanation is the LED has failed, and needs to be replaced. If the rest of the boiler is working correctly (switch on a hot tap and you should be the boiler ignite), it’s not essential to change the LED.

Explanation 2: PCB Failure

The Printed Circuit Board (PCB) is what powers the light on the control panel. If there is a connection failure, it’s likely some or all the lights will stop working. Again, if the rest of the boiler is working correctly, it’s not essential to replace the PCB.

If the PCB is affecting the operation of the boiler, the PCB will need to be replaced. The problem is, a PCB for a Worcester Ri is going to cost a few hundred pounds to replace.

Again, the big issue here is without a PCB, you’ll not be able to run any diagnostics if any other problems occur.

For those that own an old boiler that’s out of warranty, it makes sense to invest in a new boiler with a long warranty. A PCB replacement can be upwards of £400, so the boiler replacement costs are usually a worthy investment for an old appliance that’s falling apart.

You can get a boiler replacement price online in less than 90 seconds here.

No Blue Light: Power on Indicator

The blue light on a Worcester Ri indicates that the boiler has power. If there is no blue light, there are a few explanations.

Worcester suggest turning off the boiler, unplugging from the mains and then firing it back up after a few seconds. This acts as a basic reset for an Ri boiler.

Explanation 1: LED Failure

Same as the “no green light” LED failure explanation above.

Explanation 2: PCB Failure

Same as the “no green light” PCB failure explanation above.

This is likely to be the case if there are no lights on your Worcester boiler.

Your two options are to repair the PCB at a cost of £400+, or replace the whole appliance.

If the boiler is fairly new and all other parts are in good condition (gas valve, pump, heat exchanger etc), then a repair is likely to be most cost effective.

However, if it’s constantly failing, it might be worth considering a replacement with a long warranty. You can get a fixed price online for a new Worcester Bosch using this form on Heatable’s website. They supply and fit Worcester boilers at incredibly low prices.

Worcester Bosch Greenstar 4000

Explanation 3: Socket Failure

There may be a problem with the socket. Check a few other electrical appliances to see if they work, using the same socket that the boiler is usually plugged into.

Blue Light Flashing: Service Mode Selected

If your Worcester Greenstar Ri has a blue light flashing, the boiler is probably in service mode — something all Worcester Ri boilers have. This flicks the boiler into a mode suitable for measuring flue gases during a service. If the service mode is selected, you’ll see a blue flashing light that pulses or 3-5 times.

Explanation 1: Switch Accidentally Selected

Some newer Worcester Ri boilers have the service mode button on the front of the boiler. Check you’ve not accidentally knocked the switch selecting the service mode.

Explanation 2: Switch Not Returned to Correct Position By Engineer

Older Worcester Ri boilers tend to have the service switch behind the control panel. When a Gas Safe engineer services the boiler, they’ll use the tool (usually placed next to the switch) to flick the switch on. When they’ve finished, they should flick it back. The service mode lights continue to flash if the engineer doesn’t return the switch to the correct position. Call the boiler service or boiler cover provider and inform them of the issue before you flick the switch back.

Blue Light Flashing: Issues with Gas Supply, Flue or Condensate

If the service mode isn’t on, a Worcester Bosch boiler with a blue light fault indicator that’s flashing might have a problem with the gas supply, flue blockages, or the condensate unit.

Explanation 1: Gas Supply

The blue light on a Worcester Bosch Ri will flash when it detects no gas supply, or low boiler pressure (you’ll know it’s the latter if the pressure gauge reads below 0.5 bar). A range of things, such as a faulty gas valve, could cause this problem.

If it’s indeed a boiler pressure issue, you’ll have to resolve the underlying problem (typically a leak from the boiler or heating system), then restore the normal operating water levels. You can read more about low and high water pressure in our guides here:

However, if the issue relates to gas, contact a Gas Safe engineer straight away.

What kind of fuel does your boiler use?

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Explanation 2: Flue Blockages

Another common reason you’ll see a Worcester boiler with its blue light flashing is a blockage in the flue. Check the flue for accumulated debris, but also for damage. A gas engineer will be able to replace a flue (where necessarily) cheaply.

Explanation 3: Condensate Blocked

This is typical in the colder months. A condensate pipe can easily freeze, causing the blockage and the blue light to flash. However, sometimes a build-up of debris can be causing the blockage instead of ice.

What’s Next?

As we’ve mentioned, you should always get a Gas Safe registered engineer from a boiler repair company to help fix any problems you’re having with your Worcester Ri boiler.

Is there anything we missed? Do you have any questions? If so, please leave us a comment below.

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  1. Sandra Smith says:

    Got hot water but no heatin plus there is no green light on tge box at side of boiler so my control panel isn’t talkin to the box at side of boiler

  2. heatingforce says:

    Hey Sandra,
    Hot water but no heating – usually the diverter valve is the culprit, but have a quick read through this first https://heatingforce.co.uk/blog/faulty-diverter-valve-boiler/

    Green light – as above, a simple LED failure, or potentially a full PCB failure. You’ll need someone to run a diagnostic to find the exact problem.

  3. Lee Tyler says:

    Hi, I have had a problem with my heating. It is a Worcester Greenstar Boiler Ri. Having had an emergency plumber out he has taken the cover off and can see that the Silver cylinder in the image (link below) is ribbed leading to him believing that the problem is that the coil is blocked. This ha led to a buildup of pressure and warped the cylinder casing and caused the gasket to fail. This explains way the water is getting super hot. The plumber believes that their has been an amount of dirt dumped in the boiler due to the magna filter being fixed to the pipe where the water comes from the Open Valve water outlet rather than the pipe that leads into the boiler whic has caused the issue. He has recommended a new boiler and a power flush. Is this my cheapest option?

    1. heatingforce says:

      Hey Lee,

      I’ll send you an email to get more details.

      The quick version.
      Filter – It’s on the wrong side, so your engineer is right, there’s probably loads of gunk in the system. There’s a bit of an explanation on boiler filters here.

      Part fault – Sounds like the heat exchanger (I can’t see the link).

      What to do – Heat exchangers aren’t cheap to fix. More importantly, if dirt’s found itself elsewhere, other parts could deteriorate quickly.

      Without looking I’d be thinking:

      Under warranty: repair
      Not under warranty (i.e. old boiler): replace
      Power flush: Just go with a hot flush. It will cost less, get rid of 99% of grime a power flush will, and put less strain on weak joints/pipes.

      Hope that helps.

  4. Kerry says:

    Hi the blue light on my Worcester combination boiler is staying on I’ve tried to unpaired and pair my thermostat as I the manual but nothing is working

    1. heatingforce says:

      Hey Kerry,

      Is it flashing?

  5. phil levy says:

    my worcester 18ri condensing boiler wont stay alight long enough to heat the rads i have hot water ive carried out the following the loft tank is full, the cylinder stat is set at 50, the zonal valve is working correctly,removed debris from the boiler filter and pipe clear ,rads balanced and bled ,the blue light on steady ,the pumps working ,i am at a loss now and on a very tight budget any thoughts PLEASE phil

    1. heatingforce says:

      Hey Phil,

      I’d have a heating engineer come and check it out.

      These two guides should help though:

  6. Carl says:

    Hello, having an issue with our Worcester Ri today. Woke up with the blue light pulsing on the front with no green light on. All rads in the house are cold. Have tried resetting and now the green light will come On briefly then go out again. Any ideas on what the issue could be?

    1. heatingforce says:

      Hey Carl,

      Between the two lights, sounds like a burner blockage, but would advise to have a Gas Safe engineer come and diagnose/fix the porblem.

  7. Mark says:

    I have 2 identical Greenstar 25Si boilers in 2 flats – after being left off for a week , both not showing any signs of life – no blue light , no indicators . Checked for power ok, water pressure ok – Can’t be co-incidence that both pcb’s have developed the same problem. Any pointers from anyone

    1. heatingforce says:
  8. godfrey says:

    hi my boiler wont turn on ive tried turning of the heating switch on the socket for 60 secs no response no flashing buttons. i have tried to switch boiler on and off as well.

    1. heatingforce says:

      Hi Godfrey,

      Please see this post that covers no power to boilers: https://heatingforce.co.uk/blog/no-power-to-boiler/

      Hope that helps.

  9. Amy says:

    I have this boiler. Then blue light is on also hot water is working but the central heating isn’t. ?

    1. heatingforce says:

      Hey Amy,
      Is it on solid/pulsing? Would need more info.

      There’s more fault finding guides here:

  10. david chang says:


    I have a Worcester Greenstart Ri boiler. This morning the boiler was working fine with radiators being hot. While I was sweeping snow outside the house, next to the outlet vent, I heard loud water gurgling sounds and later the boiler stopped working and radiators became cold. I tried resetting it a number of times according to the manual, the green burner light was on and off and the blue light was on for a second or two on a couple of occasions. I tried resetting again for a number of times this evening, but was unable to get the boiler working at all. Both the green and blue lights are off, I can hear the boiler trying to fire up with a spinning sound then followed by more gurgling noise, it sorta sounds like air is circulating in the water tank. Any idea what might be wrong.

    Thank you very much in advance.


    1. heatingforce says:

      Hey David,

      I’d start by checking the condensate isn’t frozen. Gurgling usually comes from air locks in the heating system but there’s a good chance with the snow the pipe is frozen (small white pipe outside, 21.5mm).

  11. Neil davies says:

    My Greenstar Ri boiler not turning off! Even when heating/water off or in auto. Up til week ago was fine and controlled via thermostat in living room. Green and blue light in. Steam coming outta vent. Radiators on.
    House too hot now!

    1. heatingforce says:

      Hey Neil,

      There’s section in this guide on thermostats: https://heatingforce.co.uk/blog/boiler-timer-not-working/

      Hope that helps.

  12. Ritesh odedra says:

    I have a greenstar 18ri
    It doesnt seem to be turning off if with thr timer at all.
    Just stays on unless we manually turn it off
    Does this eliminate the boiler from the issue

    1. heatingforce says:


      Have you flicked through this? https://heatingforce.co.uk/blog/boiler-timer-not-working/


  13. Al Sherwood says:


    so obviously super cold this morning
    boiler not working
    have defrosted the condensate pipe,
    restarted the boiler but now the blue light is coming on and staying constant, but there’s no noise from the boiler and no green light at all

    any advice please?

    1. heatingforce says:

      Hi Al,

      Are there any fault codes being displayed?

  14. Naba says:

    Hey! We have Baxi Solo boiler (not sure about the model)
    Initially a red light was coming up saying the boiler heating
    Now except on, the other two lights aren’t coming on. And there’a No ignition in the boiler

    1. heatingforce says:

      Given the weather, the vast majority of boiler lock outs are a frozen condensate pipe.

      Is there a fault code being displayed?

  15. Amanda Hughes says:

    Hi I have a Greenstar i erp boiler fitted dec 2016, the condensate pipe froze on 1/3/18, I managed to sort this out and the heating was on constant for 2 days, I put it back to timed last night, and now the pressure is 0 and when I try to fill it, I can hear the water but the needle doesn’t move. I’ve pressed the info button and it states i1 system standby saying it’s waiting for the heating system to cool, but it hasn’t been on since yesterday?! I’m at a loss!

    1. heatingforce says:

      Hi. Have you got someone with you to check it’s not coming straight over the overflow outside?

  16. Michael clarke says:

    Hi. I have a 18ri and was working fine this morning and now have come to realise there is no heating or hot water. The blue light it on solid and the green light is off. If I turn the boiler off and restart in the reset position the blue light comes on but the boiler does nothing and then when I move the dial from reset to max the boiler sounds as if it is working and the green light comes on for roughly 5 seconds but then sounds as it is going to explode and the pipe start creaking and the green light goes off and the boiler does nothing. The blue light is on solid the entire time. It is not a cold day. Any help please.

    1. heatingforce says:

      Any fault codes being displayed? Could be anything from gas supply to air locks.

      This might help in the mean time: https://heatingforce.co.uk/blog/noisy-boiler/

  17. Gavin says:

    Hi there, Greenstar 28i here, maybe 10 yrs old (no digital temp or code display if that helps date it).

    Green light comes on when boiler powers up and then goes off. Does not come on when I run hot water or ask for heating, but I do hear the fan working both times and blue light is steady. Water and rads are cold. If I leave things then after a while boiler goes into a fault mode with reset button and blue light flashing – resetting puts everything back to the start of this message.

    I’ve tried power off for several mins (5+) but no change.

    I’ve no problem calling out an engineer if needed, just would feel daft if it’s a quick thing I can check myself but I’m scratching my head!


    1. heatingforce says:

      Hey Gavin. It could be a number of things, so I’d go ahead and call and engineer. Thanks.

  18. Haran says:

    I have a Greenstar ri. The blue light is on constant but the boiler won’t fire, no green light. On turning off and on the fan briefly runs for a couple of seconds and then nothing.
    I removed the flue to check for blockages and cranked the thermostat up to 30 and then it worked.
    Turned it off, reconnected flue and tried again, no green light same initial fan then nothing. I’ve disconnected flue again but now can’t get the boiler to fire at all.
    I’ve checked pressure and topped up so it’s at 1.5 bar.
    Any ideas please?

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