Leak from plastic 'connector' in Worcester Bosch 28i

Joined
25 Jan 2006
Messages
492
Reaction score
1
Location
Manchester
Country
United Kingdom
Hi all.

I'm afraid I don't know the correct term for this part and I'm struggling to find a manual/parts diagram to correctly identify it.
The boiler (Worcester Bosch 28i - not junior range) is approx 12 years old.
We moved into this property just before xmas, and lo and behold the first thing to fail was the boiler. It seemed to struggle if the hot water was running, the heating was on and another tap was running. Loud cranking noise and the 'kettling' sound was heard. I couldn't find the reset button at the time (turning off via mains and temp down to lowest didn't work). The reset button on the top looked more akin to a screw - later found out this would work by pressing it down.

Anyhow (attempting to cut a long story short)...a plumber we knew, thankfully, popped round just before new year and helped take a look at it. Turns out the pressure was 'wizzing' out of the relief pipe to the outside (initially dripping) which was then identified as a problem with the pressure relief valve (pressure gauge was dropping to near zero over time). New one purchased, replaced and all was well...

...until the last two weeks. Seem to have that cranking sound back before the boiler turns off. Simple reset and it seems stable for the next three or so days before the cranking/turning off routine.

Today - arrived home and boiler was off (and it's blinking cold today) - quick check of pressure gauge - down to zero...must be a leak? However before going on a leak hunt it was very clear the leak was coming from the bottom of the boiler. Opened the front up and identified the leak coming from the part circled in the picture below. This is the black plastic part which connects the pressure relief valve to a copper pipe (again, not sure what this is - cold water inlet?!).
Fairly certain it is from a pinhole/split (just by the way it's spurting out) rather than a leak from the connection to the copper pipe.

Mopped up underneath and stuck a bowl there and rushed off (in desperation) to try and pick up some jointing compound which 'might' work on plastic (don't really want to worry our plumber on a sunday evening) but everywhere was shut.

Tis cold...we have three children...and I'm not confident of tackling this one. Think I might stick the heating on later, run a bowl of hot water for the washing up and keep watching a bowl underneath fill till at least we have warmed up a bit. I don't suppose a few wraps of PTE tape and anything else over the leak would help slow the flow for a short while?

I need to know a: if there is a quick fix (joint compound) I can do tomorrow b: if this part needs replacing (most likely) c: if anything else is causing the 'cranking' which precedes the boiler turning off (unless this part has slowly deteriorated until it has split?

Apologies this is a bit long winded...the typing is warming me up somewhat!

Many thanks.

*
WorcesterBosch28iPart.jpg


* The leak appears to be originating from a pinhole bang central to that red circle i.e. before the joint to the copper piping.
 
Sponsored Links
...just to add, the rads have been bled and inhibitor added when the pressure valve was replaced. Checked the relief pipe to the outside and that is as dry as a bone. It might be the leak is from the connection to the plastic part from the copper pipe (clamped by the looks of it).
 
That's a likely spot for it to leak from. It's the primary flow manifold. Have a look at http://www.worcester-bosch.co.uk/in...ure/28i-discontinued-november-2005-literature for literature on this boiler. The parts list will give numbers for this part, if you order it yourself be aware that you'll need all the O rings as well which are different part numbers. Check before ordering that it doesn't come as kit with all the O rings first though.
 
That's a likely spot for it to leak from. It's the primary flow manifold. Have a look at http://www.worcester-bosch.co.uk/in...ure/28i-discontinued-november-2005-literature for literature on this boiler. The parts list will give numbers for this part, if you order it yourself be aware that you'll need all the O rings as well which are different part numbers. Check before ordering that it doesn't come as kit with all the O rings first though.

Part number 16 - found it (and good to get a name for it too).

As I mentioned in my original post, the boiler has been quite stable since the relief valve was changed (the pressure gauge fluctuated between 1.5 and around 2.8 (near 3 at least!) but seemed to follow a pattern (higher when the CH was on). Then over the past couple of weeks the dreaded kettling has returned. Zilch coming out of the overflow outside, so I guess this primary fold manifold has begun to deteriorate over the past few weeks (the way it's 'p****ing' out water though looks more like a crack/split).
I've left the boiler off now (on zero pressure) - as soon as I've refilled up to 1.5 bar, that leak sends the pressure hurtling back down to zero within 10-15 minutes (oddly I'm still getting hot water).
Advisable to refill system, use bowl to catch water and heat up the house a bit, or will I be introducing too much oxygen (after refilling a good few times over the past week and once tonight (due to heavy loss of water)?

Easy enough to fit (will bear in mind the o rings)? It's tight under there.

Not the time of year to be thinking of a new boiler, but come spring a possibility - starting work on the house so a few rads will have to be moved/replaced and radiator pipes buried in the walls (possibility using hep20, but that's for another day and thread).

Many thank for your reply.
 
Sponsored Links
Running the boiler with the leak may damage other components so I wouldn't.

It will be a pain in the rear to change, they always are, but no great technical knowledge required.
 
Running the boiler with the leak may damage other components so I wouldn't.

It will be a pain in the rear to change, they always are, but no great technical knowledge required.

Ok. The five of us will be bathing using a kettle and a washing up bowl for the forseeable future...heater and thermals out too! :)

Incredibly, google has, apparently, never heard of a primary flow manifold...not asking you to waste your time explaining the technicalities of it, but in a word - what does it do?!

Think there is a local plumbers merchant who supplied the pressure relief valve, so there's a chance they have these in stock.

Many thanks.
 
Just joins several bits of pipe together really. Nothing fancy. any decent heating spares place should be able to get one for you, If you go looking for one they it helps to take the GC number or serial number of your boiler in case there is more than one option. I don't think there is in this case but it doesn't hurt.
 
Just joins several bits of pipe together really. Nothing fancy. any decent heating spares place should be able to get one for you, If you go looking for one they it helps to take the GC number or serial number of your boiler in case there is more than one option. I don't think there is in this case but it doesn't hurt.

Struggling to get hold of our plumber at the moment - most likely on another job. Were I to pick this part (and associated O rings up) how difficult is it to change over? Would I need to turn the water mains off and the electrical mains (boiler has own MCB)? Any special plumbing tool I would need?
Once I locate a supplier I guess I could ask them over the counter....

Not entirely confident mind and not a good time, financially, to pay for Worcester engineer to attend.

Cheers.
 
For what it'd cost you in time abd money, I'd look at fixed price repairs...

The manifold is easy to take out but you will need a full washer kit because you never get the washers you need.

The noise and high pressure sound like a circulation problem

Possibly your pump.

Private RGI? £200-300?
BG? £99 and £20 a month for a minimum of 12months, with near unlimited callouts.

Bite the bullet.
 
For what it'd cost you in time abd money, I'd look at fixed price repairs...

The manifold is easy to take out but you will need a full washer kit because you never get the washers you need.

The noise and high pressure sound like a circulation problem

Possibly your pump.

Private RGI? £200-300?
BG? £99 and £20 a month for a minimum of 12months, with near unlimited callouts.

Bite the bullet.

I'm told a 12/13 years Worcester Bosch is not really that old (until I read through many of these threads yesterday I had those boilers at the top dogs...seems that's not the case these days.
Trouble is, the boiler is in the kitchen where the fridge should be (small kitchen) - the fridge being in the back porch. Thinking in the future of moving boiler into the loft and using the space vacated for the fridge. Loft will be converted into a 'study/office' which will probably mean we won't have space for a system/sealed boiler. Typical 1940's/50's semi detached - 3 beds one bathroom (7 rads) - may extend in the future to the side two storeys and back one storey (including second shower room/WC). So any new boiler would have to bear that in mind...and it might have to be combi again (Broag?). Condensing?
Wished I'd never started reading the boiler threads on here...copper vs plastic wars (I was thinking of burying raditor piping into our walls and re do with Hep20...now thinking of copper...!? :confused:

I think when we do purchase a new boiler then those fixed price repairs would be a fine idea...shivering my breasts off this morning 'bathing' in a washing up bowl! :eek:

In the meantime I've got in touch with our plumber (quite handy on the heating engineering too - the boiler in our last house, Ravenheat, blew it's PCB - he repaired it with a bit of fiddly soldering - worked a treat. He's coming round to look at the boiler bearing in mind the part that has broke/split.

Will update.
Thanks for all the advice.
 
The noise and high pressure sound like a circulation problem

Possibly your pump.

Pump has been checked (not thoroughly to be fair) but seems ok. Runs as it should, sounds fine, electrics good. But of course, I'm not certain.
It's just the past couple of weeks I've got the kettling/clanking for several seconds, usually every 3/4 days (akin to when the relief valve went). Same happened yesterday but with the conclusion of a spurting primary fold maniflow (and drenched cupboard!).
 
Just an update. It was indeed the primary fold maniflow which had split.
Our plumber/engineer duly replaced this and all was well...for about a week.

What's happened since is a follows:

The hot water (especially in the kitchen sink almost directly next to the boiler) is, well, boiling hot (too hot to touch). Upstairs not as bad, but I guess given where is has to travel it has cooled slightly.
My hunch is that the thermostat (or it's equivalent in the Worcester Bosch 28i) has gone. Then every 1 - 2 days the pressure gauge reaches over 3 bars and shoots a stream of hot water from the pressure releif valve pipe outside (which is a bit of a hazard where you to be outside when this happens), the pipes crank a fair bit and the boiler turns off (you can smell the 'radiator water' smell inside the boiler cupboard. In all fairness this has not happened in the last 2 - 3 days - even though the heating has been on and baths run etc. Possibly down to the gas pipe (uncovered on the outside wall) not liking those recent sub zero temperatures?

We are looking at replacing the boiler in the future (moving it out the kitchen so we can fit in a fridge), but not at the moment for financial and winter reasons!

Any idea, given what's occured with this boiler, (replacement pressure relief valve and primary fold maniflow) what else might need looking at - certainly something to do with the temperature (hence the thermostat suggestion).

Thanks - apologies if I should've started a new thread for this.
 
Hi Northbeach. I have a similar problem with my worcester boiler. I was just wondering how much you paid the plumber to fix it as I want to pre-empt how much to put aside.
Thanks
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top