UKC

Calling all UKC heating engineers:

I noticed a leak today from my combi boiler which is a Worcester 28Si II and is now about 13 years old (the rate of leakage is about a 2 drips/minute.) I've removed the cover and taken a couple of photos of what appears to be the source:

https://www.flickr.com/photos/70132285@N07/25673388482/in/datetaken-public/
https://www.flickr.com/photos/70132285@N07/25699286431/in/datetaken-public/

In theory, it looks as if it it's just a seal that's gone so I wondered if it were possible to fix it myself, but I don't mind getting an expert to come in and make sure it's done properly...and with zero leakage if things were to go wrong!

I've downloaded and had a look at the installation manual but can't see the part described.

I'd be grateful for any advice the experts on here can give.

In reply to Fraser:

Just replace the seal, it will cost pennies from a merchants

In reply to dingbat46:

Yeah, I'm sure the seal will be pennies. But how easy is it to get it out, what's the seal called (or the parts it goes between) and is it simply a case of pushing off the two flange-clamp things?

I find it hard to believe it's just two flat flanges with a rubber ring compressed between the two parts. Does that black plastic link pipe just pull out one I've removed the clips?

Finally, any idea how much water I should expect to come out?! Sorry - too many questions, I know.

In reply to Fraser:
That's the flow switch mate, and yes it is only held in by those silver clips. There are o rings, not fibre washers either side if I remember (will double check in the morning)
If you feel confident then I don't see why you can't do it yourself
Isolate the electrics to the boiler. It's only the domestic hot water side you're interested in so isolate the cold water main going into the boiler and then open a hot tap. Cold main is the second from the right by the way.
Get into the boiler like you have in the photos and pull down the fascia panel so you have better access.
Remove the wiring going into the flow switch via the small white plug.
Pull out those wee silver clips and change the o rings. Make sure you put some silicone grease on them before rehousing.
Reverse above and jobs a good un.

In reply to Jonny S:
Cheers for the analysis. How straight forward is it to drain the system? Can I just switch off at the mains (ie. elec.) and that'll prevent the pump from running? I can't actually shut off the water in the flat, only 3 floors down at street level, so if I can avoid doing that, so much the better.

I'll check the installation manual to see if there are details of how to drain it.

Thanks again.

Sorry, have re-read your post and see it describes the procedure there, d'oh!

In reply to Fraser:

No worries. Yes, isolate the boiler at the fused spur/plug etc. Get an old towel as there will be somewater when the flow switch comes out and you don't want any of that on the board that sits under where you'll be working!

In reply to Jonny S:

Thanks, will do. Presumably best to replace both o-rings while the switch is out?

In reply to Fraser:

Always.

In reply to Jonny S:

Cheers, I owe you one.

In reply to Fraser:

Bloody hell, someone asked a question and someone who is obviously knowledgeable and familiar with the issue gave a good solid answer.
Am I still reading UKClimbing or have I accidentally stumbled on a parallel universe? I thought these questions were supposed to get a few replies along the lines of "why are you asking X question on a climbing forum?" then half a dozen others where people who know jack all about the case in point talk rubbish followed by a fight breaking out about something totally unrelated like is three pebble slab HVS or E0?

In reply to gethin_allen:



I can see why you might perceive it as a pivotal moment in UKC history!

In reply to gethin_allen:

I'm equally impressed with the answer! What a star.

So impressed in fact that I'm tempted to go and take my own Worcester boiler cover off and have a poke around.

In reply to Babika & others:

Couldn't agree more. I'll let you know if I end up, Tom & Jerry style, with blackened face and singed whiskers. Hopefully not!

In reply to gethin_allen:





..................There's still time.

In reply to Fraser:
Yes, o rings definitely Fraser, you're after bottom size 17.6 ID x 2.4mm. Top o ring is 2.62x15.54mm ED70
There is a small wire basket flow regulator that will fall out of the bottom when you disconnect the flow turbine so make sure you don't lose it. Also, make sure you replace the part with the arrow pointing up (flow of water)

Glad to have put UKC to rights!

Edit: not wanting to insult your intelligence but make sure there aren't any hairline cracks in the plastic housing of the flow switch itself, causing the leak. I doubt it as it would be more prominent than it is but you never know...

In reply to Jonny S:

Thanks, if the flow switch itself isn't too costly, is it worthwhile just replacing that too while things are disconnected?

In reply to Jim Fraser:

You can't beat good, knowledgeable advice.

In reply to Fraser:


I wouldn't just get a second set of o-rings for when you do need to replace it.

How did it all go?

In reply to krikoman:

Thanks for the suggestion. I won't be able to get to the plumbers merchant til the weekend so it'll be a few days yet before I give it a creak. Not literally I hope!

In reply to Fraser:

It might be worth getting a spare spring clip, the rusty on might break when you take it off. They should be pretty cheap if you can buy them separately.