Worcester Bosch Greenstar 28i Junior Syphon/Condensate Trap Blocked Problem 

Thanks for sharing this tip Danny!, after installing new rads a year ago, we must have gathered a load of grit in the syphon tube of our Worcester Greenstar 28i Junior. Removing the cap and clearing the gunk stopped the boiler going into fault every 10 mins. Would recommend to look carefully underneath, there is a "tube within a tube" and you must un-block all!, have a roasting tin on standby as the water will gush out.

Legend, I watched a plumber do on a call out years ago, I suspected this was something I could do myself and you proved me right, warm flat now. Thanks!

Thanks for this video, it saved my family from freezing. I have called the engineer, but they were extremely busy and after hours of waiting I decided to try to fire it up myself. I had to fans running constantly for hours and house was getting colder. My boiler had the same symptoms and after increasing the pressure and cleaning the pipes (that were full of blue sand) it started working again.

literally found this video after trying about 8 different things to "fix" the problem and was just about to book a service/repair as I have no skills in this area. shoved a straw up there and overflowed the bloody bowl i was using but sure as anything - no problems now. thank you !!!

had the exact same issue in a rental property tonight, Was totally blocked up, cleaned it out, turned boiler back on, reset it and back to working with plenty heat and hot water. Many thanks for your video !!

Bloody awesome tip. Worked like a charm after wasting half an hour pouring boiling water over the condensate pipe thinking it was frozen and getting nowhere.

I would like to say you are an absolute legend for sharing this. I am now in a warm house tonihht thanks to you. Legend!

Thank you so much our boiler packed up and this advice saved me a fortune!

spot on ... 10 mins work and it seems to have fixed it ... and running quieter now too ... thanks !!

Absolute champion! Boiler runs a dream now

Fantastic info . Had very high pressure for 3 days , then worked fine for 2 days then suddenly no pressure and a water leak from a small pipe next to the cold inlet . Didn’t notice the leak till it had filled a wellie boot under it and soaked the floor !! Neighbours a plumber of sorts , came to look , scratching his heat and said “ring British Gas “ They couldn’t come out for 4 days although we now had no heat and water . Watched ur video and sorted in 2 mins . Running fine now although we booked in for full service ASAP

You Sir are a true gent, had the flashing reset the exact same fault as you, cleaned the gunk out now central heating working again. Happy Holidays

Thank you very much.. after waking up to no heating or water....I eventually found this video. Really appreciated

Did exactly what you said. Same result. Boiler back to working order. Many thanks 👍🏻

Mate. Thank you. I was so close to calling a plumber. Your video was the last one I came across and it was the one. Nice one.

Worked well on my 24i. Thanks for sharing!

You are a legend!!!!!!! My was clogged up and now working

🎉🎉🎉🎉great video thanks you saved me a couple of hundred and now I got a nice quiet boiler without any fault!!! Five star plus mate🎉🎉🎉

Thank you for this video Just what I needed to fix My boiler that had no hot water or heating and you have saved me cash. Well done mate.

You my good man, are the best. My boiler was booming. Really low frequency, loud vibration sound, like some of those guys with excessive bass in their car. I followed your tutorial, and the boiler is back to working the way it should! Top man. Thank you!

Thank you so much for sharing this !, I have it couple of days the problem with the flashing lights on the boiler ,but today even reset wasn't work I did have it hot water :(when I saw your video I know it is exacly the same issue what I got , straight away go upstairs and have look, I switch off from the power, remove the cap and water was so dirty!!!, Now My boiler stop be noisy ,Hot water back ! : -))))) THANK YOU ! you are Legend!!!!

Just did this myself by accident whilst trying to figure out whether I could repressurise my boiler's expansion vessel. I thought that maybe the valve for the expansion vessel was under the removable plastic cap (which I only later discovered was for the syphon!). Imagine my surprise when a load of metallic sludge came pouring out! Cue 15 minutes of cleaning. I phoned the Worcester engineers who said "you shouldn’t be fiddling with your boiler, sir" - a fair point, but I regard anything plastic and cap-like as fair game (in my view if something is easily accessible and can be removed by hand it can't be that dangerous/critical). One thing he did say that worried me slightly is that the water in the syphon works as a trap to prevent the escape of carbon monoxide and (during a service) the syphon should be refilled with fresh water to form a new trap. Anyone else heard this - or was he just trying to put the frighteners up me? How long does it take the condensed water to form a new trap? I've got a carbon monoxide meter close by which is still nailed to '0 ppm' (as always) so not overly worried. Glad to see you did exactly the same as me (albeit on purpose!) and you haven't had any problems.

I tried this too after watching your video.. you saved me calling a plumber out thank you 👌😊

You absolute hero, had rang about 3 different boiler repair men (none of which bothered to answer their phone) before desperately looking to RU-vid. Unclogged the pipe and voila, back in business!! Thanks again!

Great tip, sorted it right out! Wasn't prepared for the amount of water that came out though 😂

Just did this and it worked a treat (so far) Thanks alot for this..like you mine decided to pack up when temperatures are Arctic

Hi , as others have said THANKS.. just fixed my boiler !! you sir are a star !

Thank you, thank you, thank you, it's so easy when you know how, you video is very much appreciated xx

cheers fella same on mine, saved me a few quid there top man.....

This worked for me - thank you so much for sharing! 😍

I had to get the british gas guy out in the end, as it turns out the pipe going into the sink from the boiler was blocked too. So this fix worked until the condensate trap filled up again. He unscrewed the pipe going from the boiler into the sink and poked a screwdriver in to clear the blockage. He ran water in the sink to make sure it was no longer blocked before putting it back together. He also noticed that I had not put the cap back onto the condensate trap properly and this is really dangerous he told me if it drops off - it should clip on securely.

You sir are a legend! Thank you so much

Thank you so much for this video , you helped me to fix mine just before I go on holiday and was stressing how to fix this , thank you , thank you , thank you ❤

Great little video. Thank you for sharing. Hooray for us DIYers!!👍 NoAxe

This is amazing! Finally fixed it! Thank you!

many thanks man , that worked a treat!

Nice one thank you, I was about to call an engineer. Also works on a green star 30si. Thank you.

Fantastic just saved me a fortune

Thanks very much it was helpful iv just fixed it after your advice

Brilliant, boiler working again, thanks

Best to call a Gas Safe Registered Engineer to work on any boiler. The case once taking off has to be re checked to make sure it is sealed back on correctly & safety checks will need to be carried out. So any DIY out there call a professional.

When you emptied the syphon how did you put the water back into it. I'm told that you have to have water in the syphon when you finish cleaning it. I could be wrong in that, just saying what Ive been told

Fantastic worked a treat. So far so good. God willing. How much do I owe you?

Thanks for video helped a lot

What a guy , thanks mate. Kids can have a bath now lol. Landlord ignoring my messages as usual. You saved the day. Have a great Christmas and new year.

Thanks so much it sorted out my problem

Do you have to refill the syphon (condensate tank) or it refills automatically? Thank you in advance.

It worked for 1 hour and then started to make the same sound again. Any help plz. I've even put hot water towel on the pipe.

Sorted. Thanks mate much appreciated 👍🏼

Omg u just saved me a £ 125 call out fee thank u so much 🙏🏼🙏🏼

Brilliant mate ! Thank you - I owe you a beer or 4 !!

It seems it sort my problem thank you!!!

Yay just done this and bingo I have heat, happy bunny 😄😄

Life saver.. cheers buddy

Thenks for your help 😎🥳👍

True same issue with 30i , paid £65 for doing that but the engineer was charging too much i guess £35/40 should be enough but there are some oppurtunist out everywhere

My boiler has started making a slight rumbling noise. (Kind of like when a kettle is at the boil and u can hear the bubbles). Happens everytime i turn on the boiler and it runs for about 2 mins. Could this be a blockage?

Nice one 👍😊

Thank you so much!!!

LOVE YOU ❤️❤️❤️

How do i switch my boiler on again as i switched it off by mistake, checking why it was staying on all day as I had pressed the over ride button??? Pressed on off button but not sure if it is back on . The eco light is green and the power on and fault indicator is blue , so not sure if its on or not

Hi, did you have to drain the boiler or system at all before removing the syphon cap ?

Hard water area? If your condensate trap keeps filling with this rubbish then possible that the heat exchanger needs cleaning (service). That is a job for a gas safe only though.

Can anyone add how to refill the Syphon? Does it need to be removed from the top?

Excellent videos mate although I'm 2 years late lol I have the same boiler when cold the pressure is reading zero when it's on the pressure goes up to 3 bar any ideas cheers

Hi do you need to fill it up with water after you empty the sludge? Thanks

Just the job...my condensate pipe was blocked by a hornet or a queen wasp!!! I guess thats the issue with not putting the heating on until a bit later this year :D

How do I change the temperature of the tap water? Can’t see any dials like other boilers?

Thanks for this video. It worked. But it stopped soon after. We emptied water again & it began working. We believe the water isnt emptying by itself. so we think the condensation pipe is blocked. So any help for unblocking a condensation pipe?

Thanks a lot ..

How did you remove the outer casing? Thanks

How do you connect your alexa to the heating???

Nice video but could have done without you setting my heating to 22 via my Amazon Echo

Does anybody now how full the condensate trap should be normally? Just cleaned ours put as was having the same issue and it's half full already a half hour after!

mine keeps flashing override .what does it mean /thank you

How did you top the pressure up?

have the boiler services as manufactures instructions and insulate you condensate our side and you will save all the problems on the videos, Also if you boiler has a long warranty you must have it services every year to Validate you a warranty, saving money in the short term could cost you a new boiler in 6 to 7 years

I doubt as you stated you should be that you are gas safe registered. It is an offence to work on a gas appliance without being qualified and registered but the condense trap forms part of the flue system and incorrectly refitiing can result in fumes escaping also anytime work on a gas appliance is done it should be tested with a gas analyser. Don't mess with things you don't understand just to save a few quid as lives cost more

I have the same issue but my syphon/condensate pipe keeps getting blocked up and there's no sludge. It's so weird. Because my condensate pipe connects to my kitchen waste pipe as I live in a flat I thought my pipe was blocked so I cleaned that. So I turn on the boiler again and it works fine, turn it on the next day to find my condensate trap blocked again. Stressful time, anyone have a similar issue?

Sorry take it back. It's shut down again. As you were.

22? are you won the lottery or what?

If you're not gas safe you shouldn't be doing this

The trap you cleaned out is supposed to have water in it .you refill it after you clean it .this is only possible to do by removing the front case and this is illegal unless you are gas Safe . By doing it this way you are in danger of poisoned gas coming into your home as the trap works like a u bend ...... You have potentially put others at risk who are copying you to save a few quid . This may cost lives

Has anyone tried this and it hasn’t worked?? Someone help me please!! 🥶🥶

WARNING. There is no water in trap now. Your family is at risk from products of combustion . Call a gas engineer asap. Do not try this at home.

In dangering people lives

This isn't a DIY job.

Your not gas safe registered and that is a gas carrying part

Not good to encourage people who are not competent to play with gas carrying parts as they don't do proper gas safety test like most gas safe engineers do