Worcester Bosch 28i Junior Developed Leak

[diychicken]

Hi,

Went downstairs last night and noticed water on the floor. It was dripping from the bottom of the boiler. Took cover off and identified the source of the problem. The black plastic piece that attaches to the auto-air valve and supplies the hot water to taps has a tiny hole in it and a very fine spray of water is coming out.

The hole is in the body of the plastic and not at a joint.

Has anyone seen this before? The boiler is about 4 years old and I don't know what the deal with the warranty will be. To me, a fixed piece of plastic shouldn't develop a leak - it's almost as if the plastic has corroded from the inside.

All our water is off at the moment.

Can anyone advise on how much it would be to replace the part (I don't know specifically what it's called - as I said above, it's black plastic in the bottom left of the boiler and supplies the connection on the manifold with a picture of a tap).

Also, can anyone advise if this should be under warranty?

Many thanks in advance.

[diychicken]

Sorry - correction - it's not by the auto air valve - it's between the DHW sensor and the Flow connection from boiler to heat exchanger.

[ChrisR]

WB are quite good at customer service. If you yell at them they'll send you a new part, ime. Sale Of Goods Act says things like that should last 6 years!
Getting it fitted free will be harder. Probably not too hard and you don't have to be Corgi/GSR for that. Manual is on their web site.

[Rob]

Ive had to replace one of these. When I phoned WB for a part number the guy said they'd had a 'few' that have gone. Howwever they've all failed when the incoming pressure was 10bar+ apparantley

It was right down in south croydon so it might have been but doubt it. I didnt bother to check

Check your pressure. You might have a case to get it done FOC

Fitting it is tricky, iirc you need to remove ALOT of stuff including a gas pipe inside.

[ChrisR]

If it's this part, yes I've changed it too. Don't remember it being hard..

WB part no in box:

[Rob]

I must be talking about the wrong boiler. I assumed he was talking about the greenstar (pictured)

It doesn't show the gas pipe in the pic either

[gaspro1981]

is it the 28i junior greenstar if so and its the part in robs picture i have done loads of these the part is called the flow manifold and they are a complete pain in the a**e to change
regarding point of failure its nothing to do with the mains water pressure but pizz poor design and build quality

[holty]

still thats why worcester say a mini expansion valve should be fitted to the cold/hot water supply if supply is fitted with a non return valve e.g water meter.to me this is just a way of wb covering there ass.due to design fault.

[diychicken]

Many thanks for everyone who replied. The arrow in the pic that rob884 posted is the correct component. I got an approved WB heating engineer out to sort it. As soon as I told him that there was a leak he knew what the problem was and which component it was. He came round within 2 hours and got it sorted and serviced the boiler - so we're very happy.

Not so happy about the quality of the component and the fact that this appears to be a common problem. In my opinion WB should have contacted everyone who had their boiler and pay for the component to be replaced. It's out of 2 year warranty but this part shouldn't have failed. It could have flooded the house - it was pure luck that I went into the utility room.

Anyway, thanks again.

[Big Tone]

I hope I can I continue this thread with my problem…

I have the WB Junior 28i too and since I moved into this house, a year ago now, it has been leaking somewhere in the system. (That’s why I read your post with great interest DIYchicken). I assume you were also losing pressure?

For myself, I have looked all around the house to find a leak which accounts for the pressure loss. It’s become so bad that I have to re-pressurise it every day and sometimes have to use restart; pressing the red button for five seconds.

I understand, from reading elsewhere in DIYnot, that prolonged use like this will be detrimental to the whole system because there will be no inhibitor in the water, so I’d like to make a stitch in time if possible.

I’m hoping that there is no leak under the floorboards and since I feel I have eliminated the radiators I am now looking at the WB combi. If the problem you describe is common then, also by process of elimination, I feel I should start looking at the boiler but if anyone knows of any other Achilles heel, either with the boiler or something I may have not considered, I’d love to know.

I really can't afford to get a plumber in.

Tony

[diychicken]

Hi Tony,

Sounds like you're having a nightmare. I don't recall losing pressure but the leak was so fine it would have taken a while for it to drop enough to spot on the dial.

For me, it was dripping from the underside of the boiler where the spray had hit other components causing larger drops of water to fall. If there is a leak in the boiler, I guess taking the plastic cover off the bottom of the boiler and seeing if anything is wet (or putting a dry towel underneath to see if it gets wet over time) will tell you if it's a boiler leak or not.

Didn't get around to complaining about the part quality to WB.

Anyway, good luck finding the source of your problems - hopefully the expert guys on here will give you some good suggestions to help you diagnose where the leak might be or what might be causing your pressure loss.

[petit_pablo]

Big tone your fault isnt going to be similar to diychicken's. The original thread was a leak on the cold main into the appliance. This wouldnt have dropped the system pressure.

On your boiler, have you checked outside. There should be a 15mm pipe coming out from the boiler to outside. This is from the pressure relief valve. If this is dripping then your pressure is being lost there. A bit of a **** to repair too.

[gigz]

Big Tone if you cant see any water check the prv termination (15mm copper pipe should be outside) if not best bet would be under the floor (it might be a compression fitting that could be tightened)

[Big Tone]

Ah right, I didn’t realise yours was the cold water supply DIYchicken, so it makes sense your pressure wouldn’t have dropped. Thanks for the tips guys.


The overflow pipe comes out in the most awkward place, upstairs over the lean-to. It’s dark by the time I get back home so I’ll have to take a look, (somehow), at the weekend.

If it’s under the floorboards somewhere I think I’ll just sell the house. Any cheap-rate plumbers here, living around Birmingham?

Oh, BTW, a guy I work with who has WB both here and at his other place in Spain asked what combi I have. (He’s converted one to LPG which was a simple valve change). Long story short, he says the old WB are good and you can still get all the parts but don’t buy a new one. In his exact words “they’re $h1t”.

He even knows someone who works there who says don’t buy one. Since they went from Worcester to Worcester-Bosh they continued to be good for a while after, before changes for the worse came into being. Common problem: There’s a PCB with a transformer which, over time, breaks a track on the PCB as the boiler fires-up. Engineers come out and charge £300 for changing it.

(Hope I can’t be done for libel? I feel the need for a disclaimer or something here…)

[123clueless]

ChrisR wrote:

If it's this part, yes I've changed it too. Don't remember it being hard.. WB part no in box:

Hi, i've just changed my flow manafold, sucsesfully! But i can't get the boiler fired up. I've pressed the reset button, but after trying for a few seconds, it isn't working. Any ideas?
Mick