Boiler Broken Down?

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Worcester Greenstar RI Boiler Problems

If you’re having problems with your Worcester RI, this guide is going to cover some of the most common faults, and potential fixes.

If there’s a cheap fix, this guide will help. If the boiler needs replacing, we can advise on the best and cheapest options. Check out our boiler replacement cost guide here.

Alternatively, keep reading, and we’ll try and uncover a few explanations for why problems are occurring and what to do next.

*Note. Do not attempt to fix your boiler. Speak to a Gas Safe registered repair company. You can do that for free on Rated People.

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 boilers where the green light was off, but the rest of the boiler was working correctly.

There are two typical explanations for no green light being present.

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. If the boiler is old, it’s probably worth looking at a more efficient replacement.

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

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.

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 Pulsing: Service Mode Selected

Worcester RI boilers incorporate a service mode. This flicks the boiler into a model suitable for measuring flue gases during a service. If the service mode is selecting this will give a blue flashing light that pulses or flashes 3-5 times.

Explanation 1: Switch Accidently Selected

Some newer Worcester RI boilers have the service mode button on the front of the boiler. Check you’ve not accidently 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 an 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.

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

A blue light flashing on a Worcester RI boiler indicates there’s a problem with gas supply, flue blockages or the condensate unit.

Explanation 1: Gas Supply

The blue light on an RI will flash when it detects no gas supply, or low pressure. This could be a range of things such as a faulty gas valve. As this issue relates to gas, contact a heating engineer straight away.

Explanation 2: Flue Blockages

Another common cause of a blue light flashing is a blockage in the flue. Check the flue for blockages, 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 colder months. A condensate pipe can easily get frozen causing the blockage and the blue light to flash. However, sometimes a build-up of debris can be causing the blockage.

What’s Next?

As we’ve mentioned, you can get a boiler repair company to help fix any problems you’re having with your Worcester RI boiler…

Still got a problem? Leave a comment below and we’ll do our best to help you fix the problem with your Worcester RI boiler.

Leave a Comment:

Sandra Smith says 13th October 2017

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

heatingforce says 16th October 2017

Hey Sandra,
Hot water but no heating – usually the diverter valve is the culprit, but have a quick read through this first

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.

Lee Tyler says 1st November 2017

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?

    heatingforce says 1st November 2017

    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.

Kerry says 25th November 2017

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

    heatingforce says 4th January 2018

    Hey Kerry,

    Is it flashing?

phil levy says 29th November 2017

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

Carl says 16th December 2017

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?

    heatingforce says 4th January 2018

    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.

Mark says 2nd January 2018

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

    heatingforce says 4th January 2018

    Hi Mark,

    Hope this helps:

godfrey says 18th January 2018

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.

    heatingforce says 19th January 2018

    Hi Godfrey,

    Please see this post that covers no power to boilers:

    Hope that helps.

Amy says 27th February 2018

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

    heatingforce says 2nd March 2018

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

    There’s more fault finding guides here:

david chang says 28th February 2018


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.


    heatingforce says 2nd March 2018

    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).

Neil davies says 1st March 2018

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!

    heatingforce says 2nd March 2018

    Hey Neil,

    There’s section in this guide on thermostats:

    Hope that helps.

Ritesh odedra says 1st March 2018

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

    heatingforce says 2nd March 2018


    Have you flicked through this?


Al Sherwood says 2nd March 2018


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?

    heatingforce says 2nd March 2018

    Hi Al,

    Are there any fault codes being displayed?

Naba says 2nd March 2018

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

    heatingforce says 2nd March 2018

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

    Is there a fault code being displayed?

Amanda Hughes says 4th March 2018

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!

    heatingforce says 5th March 2018

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

Michael clarke says 2nd April 2018

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.

    heatingforce says 6th April 2018

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

    This might help in the mean time:

Gavin says 20th April 2018

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!


    heatingforce says 28th April 2018

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

Haran says 21st April 2018

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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