# Second Hand Gaggia Classic Overhaul - loud and leaky



## Bellybud (Nov 2, 2021)

Hi there, new to the forum but a lover of coffee!

After watching a James Hoffman video on getting great coffee from a Gaggia Classic I decided to dive in and get a second hand machine and 'fix it up' to make great coffee.

However, in my enthusiasm I paid too much and I think the machine needs a lot of work. The inside looks a complete mess and I don't think it's ever been descaled/cleaned/serviced. There also seems to be a leak coming from the inside; I cannot see where from but I have recorded a video of the inside and I think it could be from the bottom of the pump which seems to vibrate like crazy against the side of the machine.

*https://www.flickr.com/gp/[email protected]/7Y1348 - Link to photos of the machine and video of rattle and espresso shot*

From what I've looked at online I will need to descale with ~5% citric acid multiple times and replace a couple of elements... Also need to learn how to take it apart to clean the inside.

*What is your advice on how I should proceed with this machine? *

Here are the things that look common to upgrade:




Shower holder



IMS Precision Basket



Gasket


Custom Stainless Steel Tune Up Kit for Gaggia. Shower holder, IMS Precision Basket, Cafelat Gasket, Screws : Amazon.co.uk: Home & Kitchen - Is this good value for the set?




Change the Steam wand for a Rancilio Silvia V1/2 - 1 or multiple hole tip?


Rancilio Silvia (V1/V2) Steam Wand : Amazon.co.uk: Home & Kitchen




Replace the OPV spring for a 9 Bar spring


Gaggia Classic OPV spring mod kit - PLUS version (springs, additional silicone pipe and bung) (shadesofcoffee.co.uk)


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## Alfieboy (Dec 26, 2018)

Welcome to the forum

Let's start with the basics - exactly what machine do you have? Perhaps a photo of the rating plate?

Neil


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## Bellybud (Nov 2, 2021)

Uncletits said:


> Welcome to the forum
> 
> Let's start with the basics - exactly what machine do you have? Perhaps a photo of the rating plate?
> 
> Neil


 Hi Neil ☺

This is the information from the bottom:

TYPE: SIN 035 (CLASSIC)

230V ~ 50Hz. 1200W

N°: TW901131404487. 31/2011

RI9303/01. 9307SCOBO011


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## Alfieboy (Dec 26, 2018)

If it were me I'd just do a complete strip down of the boiler, solenoid and OPV and change all the seals for a start

That gives you an opportunity to clean everywhere too

I first of all normally mark and photograph then remove the wiring harness apart from the front switches and pull it all through the front and then get my Allen keys out

I can't see where the pump is leaking from the video so I'd try to see what is happening there before you strip it down - they are usually available if necessary

Its the sort of Classic I love to work on so there is lots of hope there


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## El carajillo (Mar 16, 2013)

As above , complete strip down required.pump is leaking and shows signs of scaling.

If you strip it down and replace the parts you have listed you will have a good little machine.

The rattling is probably because the pump mounting (rubber) has perished.

Plenty of help and guidance available on the forum.


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## Bellybud (Nov 2, 2021)

So I have now fully stripped the machine, surprised by how easy it was to take apart, good design!
*https://flic.kr/s/aHsmX3Kws4 - Gaggia Classic StripDown*



> I first of all normally mark and photograph then remove the wiring harness apart from the front switches and pull it all through the front and then get my Allen keys out


 I have disconnected all of the wiring, when removing the plugs from the boiler there is a white paste in the seal, what kind of paste is it so that I can get some more please?

The boiler looks quite grim, I've uploaded some more pictures (link above) but I'm not sure whether citric acid/wire brush will remove the scale without removing too much metal, what do you think?



> The rattling is probably because the pump mounting (rubber) has perished.


 If you mean the rubber that connects to the base plate then it now quite stiff, should it be soft?

The other point of concern is the pump casing. As you can see in the pictures there is heavy rust but I'm not sure that this will affect its functioning currently(?).

I located the source of the leakage and uploaded a video of it leaking from the top of the pump where it connects to the right angled metal connector; I imagine the slow drip of this has caused all of the wear below it. I think it could be fine once it's cleaned and tightened properly, do you agree or should I replace the pump all together? (£20 on amazon).


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## Bellybud (Nov 2, 2021)

Also, having now taken it apart I can see that the OPV on the classic seems to use a hex nut to adjust the pressure rather than a spring. Therefore, there would be no reason to buy the shades of coffee OPV mod kit if I've understood correctly.

Does anyone know what the default setting (pressure in bar) for the hex nut and when/why I would adjust it?


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## AndyDClements (Aug 29, 2016)

the Shades kit is specifically for the new model where it's not adjustable. Yours is one of the older ones, so has no use for that kit.

To set it you'd need a pressure gauge to fit on the portafilter, then adjust the hex until you get the desired pressure. If you don't have access to a pressure gauge, then either don't adjust it, or if you sisassemble it make a not of how many turns it was at to start with.


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## El carajillo (Mar 16, 2013)

Replace the pump and it's mounting. (if you try to reuse it it will probably split when you try to refit the elbow with PTFE)

The white paste is thermal paste (computers etc) not absolutely essential.

The boiler will clean up fine.


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## Alfieboy (Dec 26, 2018)

@Bellybud that boiler is perfectly okay from what I can see

The OPV should be stripped down and cleaned with Citric but use mechanical means on the inside of the boiler

Try to set the OPV to 9 bar if possible (I believe someone measured that physically as 11.5 mm from top of the Allen key adjuster to top of the OPV)


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## ratty (Sep 22, 2019)

As the spring is not under a lot of tension under the hex key adjuster (Sorry I used to work for a rival of "Allen" and it was a criminal offence to call them Allen keys! lol) they usually do not wear down, and so the 11.5mm measurement is usually accurate enough to give you a ball park figure between 8.75 bar and 9.25 bar until you decide to get it even more accurate with a gauge.

For me looking at the pics I would buy a new pump, available with an online search for around £15. The rubber mount looks fine. When fitting the connector to the top pipe and the top of the pump, use plenty of PTFE pipe tape to prevent leakages.


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## Bellybud (Nov 2, 2021)

Thank you for all of the help! I've ordered a new pump and some PTFE tape to prevent further leakage. Also ordered new silicone O rings, a backflush blank, new gasket/basket/shower and rancilio wand. Really looking forward to cleaning and putting this back together! Is it worth replacing the rubber tubing which draws the water from the tank, If so, what should I be ordering?

I plan on cleaning everything tomorrow, do I just soak everything in 5% citric acid and use a kitchen sponge to wipe off rust/limescale?


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## El carajillo (Mar 16, 2013)

The citric acid will remove the l/scale, use k/sponge and kitchen cleaner initially, try not to scratch the stainless.

Remove the tubes from the tank and leave them to soak in hot water with some Milton in (steriliser)

just buy a small bottle (supermarket or chemist) Always useful for sterilising water tank etc.

Method S/S cleaner is good for polishing the case. (s/market)


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## Bellybud (Nov 2, 2021)

So... I've cleaned everything with citric acid and replaced all of the O rings. I've put the *machine back together* and it looks nice... BUT,* it won't turn on*. Every time I turn on the switch it trips the fuse board.

https://flic.kr/s/aHsmX4UhiA - link to the reassembled photos.

I thought that it could be that wires 3 and 4 or 6 and 7 were the wrong way round but having tried every combination it isn't that. I have double checked the numbering of the wires from before I disassembled the machine and I cannot see any issue. I have used compressed air to ensure that all of the connectors are dry.

Can anyone see the issue or able to suggest any other reasons is may be happening?


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## AndyDClements (Aug 29, 2016)

Popping things (even whole machine in a warm not hot) oven to dry out may solve any residual water in the connections.

The image of the boiler mating surface makes it look quite pitted, I'd recommend flattening it to help get a good seal that will last.


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## Bellybud (Nov 2, 2021)

AndyDClements said:


> The image of the boiler mating surface makes it look quite pitted, I'd recommend flattening it to help get a good seal that will last.


 Thanks, I'll try putting it in the oven now!

How would you go about flattening the mating surface?


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## ratty (Sep 22, 2019)

I wouldn't worry about the mating surfaces until after it started leaking.

I put it in the oven on 100c for an hour


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## Bellybud (Nov 2, 2021)

ratty said:


> I put it in the oven on 100c for an hour


 100C??? Wow, mildly scarred the plastic/rubber on the wiring will melt but sure, I'll trust you. One hour to go!

Not going to lie, my wife is looking at me like I'm crazy now 😂


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## ratty (Sep 22, 2019)

What wiring?

All wiring is removed!

You just put into the oven the boiler with nothing connected to it.

Edit I missed the post with someone saying to put the whole machine in the oven! I wouldn't do that


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## Bellybud (Nov 2, 2021)

Yep, currently the whole machine is in the oven 😂 I went for 80C in the end so hopefully nothing has happened


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## Bellybud (Nov 2, 2021)

Good news, nothing melted.

Bad news, it is still tripping the fuse board when I try to turn it on.


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## Alfieboy (Dec 26, 2018)

Only put the boiler in as per @ratty

Nothing attached as in your final photos then you can make the oven a little hotter if necessary

I put mine in if needed with the terminal pins facing down to encourage moisture out


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## Bellybud (Nov 2, 2021)

I found an older post about the fuses tripping after stripping and cleaning the Gaggia Classic. They had fully submerged the Gaggia in Sodium Hydroxide to descale it and thus the heating elements got water clogged in them. This was solved by un-earthing the machine and running it for 15 minutes for the elements to heat up and dry.

https://www.coffeeforums.co.uk/topic/21679-gaggia-classic-tripping/?tab=comments&do=embed&comment=280268&embedComment=280268&embedDo=findComment#comment-280268

I have now unearthed the machine and turned it on, similarly water is now sizzling out of the heating elements. Will let this continue for 15 minutes and then re-earth the machine and see whether it runs... Watch this space!


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## Alfieboy (Dec 26, 2018)

@Bellybud Please be careful you have a "Live" appliance there


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## Bellybud (Nov 2, 2021)

I truly appreciate the warning, thank you.

It has worked though! Listen to that new pump pump! (it is now grounded whilst doing this). Just need to wait for the new wand and group head to arrive tomorrow and I'll be on my way. Very excited and extremely grateful for the advice from you all 😊

https://www.coffeeforums.co.uk/index.php?app=core&module=system&controller=embed&url=https://www.flickr.com/photos/[email protected]/51657633419/in/dateposted-public/


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## AndyDClements (Aug 29, 2016)

I'd said warm oven not hot, so that's such as when you've finished baking and it's already cooled a lot, and is turned off. That was because you'd already re-assembled it.


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## Bellybud (Nov 2, 2021)

Turns out, the boiler is leaking from the seal now. Will take it apart again tomorrow and try again. Anyone advise on making sure you get a good seal between the boiler sections?


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## AndyDClements (Aug 29, 2016)

Abrasive paper (wet & dry is best but if not using that then make sure it's dry) on a flat surface (slate kitchen chopping board?) then move the boiler around on it. 80 grit or something, you could finish it off then with 120 or similar, hasn't got to be polished just not gaping craters.


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## Bellybud (Nov 2, 2021)

I've uploaded new Photos and videos of the sanded boiler, leaking steam wand and espresso shot pour. *https://flic.kr/s/aHsmX66cSV*

*Great News*: Sanded down the boiler and it now seals well, no more leaky pump and no more water in the heating element.

*Sad news:*



The *steam wand now leaks/steams* when idle. I've flushed a lot of water through the Steam Valve Assembly both directions to see if anything is blocking it from sealing off correctly but nothing is coming out. and it still leaks from the wand. Any ideas or is it likely to be another new part?


I've made a few *espresso's* with 2 different beans (both ground by the shop for espresso) and they're both *really sour/bitter*. 18g for both, 1 is a medium roast and the other a dark roast. The shots from the dark roast have no crema so I assume it's poor extraction. I've tried using the Gaggia Perfetta Crema Double Filter Basket which improves the flavour but not by much. Have I likely adjusted the OPV incorrectly (11mm between top of the raised hex nut and the top of the OPV) or is this likely to be linked to the leaky steam wand?


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## AndyDClements (Aug 29, 2016)

Steam wand, there is a remote chance that it's a fragment of limescale, and putting descaling solution down there may help, but I did say remote.

Rathjer then new part. There's a post that shows grinding/filing off the burr so that the wand can unscrew completely, re-shaping the needle and replacing seals, then threading to accept a pipe fitting that will prevent accidental (dangerous) completely undoing the wand when in use.


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## 29243 (Feb 8, 2021)

That shot liked really fast, which would explain why it's sour. You need a finer grind.

Grind size is pretty sensitive, and it's pretty much impossible to get it ground the right size by a shop. If you want good espresso them you really need your own grinder so you can dial the right size in.


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## Bellybud (Nov 2, 2021)

AndyDClements said:


> Steam wand, there is a remote chance that it's a fragment of limescale, and putting descaling solution down there may help, but I did say remote.


 I'll try running citric acid through it before looking at modifying parts, thank you 😊



BenH said:


> That shot liked really fast, which would explain why it's sour. You need a finer grind.


 I bought the espresso grind because I don't currently have an espresso Grinder so that's a shame.

Currently looking for a grinder on eBay, looking for a Sage grinder or 2nd hand Super Jolly.

Can I pass the espresso grind I have back through a machine when I get one? 🤔


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## 29243 (Feb 8, 2021)

I'm not sure you can regrind unfortunately. Probably your best bet is to use the pressurised basket.

To set the pressure correctly the easiest way is a portafilter pressure gauge. I got this one: https://www.ebay.co.uk/itm/281465311077


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## El carajillo (Mar 16, 2013)

Bellybud said:


> I'll try running citric acid through it before looking at modifying parts, thank you 😊
> 
> I bought the espresso grind because I don't currently have an espresso Grinder so that's a shame.
> 
> ...


 NO.


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## newdent (Feb 20, 2021)

Bellybud said:


> I've uploaded new Photos and videos of the sanded boiler, leaking steam wand and espresso shot pour. *https://flic.kr/s/aHsmX66cSV*
> 
> *Great News*: Sanded down the boiler and it now seals well, no more leaky pump and no more water in the heating element.
> 
> ...


 I've just been through a very similar process with my recently purchased second hand gaggia.

There's no guessing the adjustment on the OPV, you'll have to get a portafilter pressure gauge as mentioned. I recommend soaking the portafilter in Cafiza a few times before attempting to remove the spouts. The leaking steam wand will be a poor seal inside the valve. If you don't fancy performing the modification yourself, some people sell them already modified but they aren't cheap. I think @rattyon here was selling one once but that may be sold?

Resolving the issue you're having with pre-ground coffee is way out of that scope of this thread imo. Just rest assured that the machine is capable of making good coffee, now you've got the arduous task of learning how to do it - enjoy! Temperature surfing will be a must for this machine, there will be lots of info on the internet.

EDIT: Just remembered, I think there is a portafilter pressure gauge doing the rounds. I guess the next person to use it just pays postage? Last person I saw had it was @Tinkstar


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## Bellybud (Nov 2, 2021)

Been a while since I last updated.

I bought a pressure gauge to check what I had adjusted the OPV to but I've now encountered a new problem, when the pressure exceeds 4 bar it starts leaking around the portafilter. I had put the filter holder gasket in upside down (duh) it it is still leaking after correcting... I had recently replaced it with the linked product below but I can see some reviews where it didn't seal the portafilter correctly. Should I buy another gasket seal from The Espresso Shop or could there be a different issue?
I've spent way more than planned in doing sorting this machine 😭
Custom Stainless Steel Tune Up Kit for Gaggia. Shower holder, IMS Precision Basket, Cafelat Gasket, Screws : Amazon.co.uk: Home & Kitchen



newdent said:


> The leaking steam wand will be a poor seal inside the valve.


 I've seen the video where someone uses a grinder to remove the brass ring allowing it to be fully screwed out if unscrewed too far. Would you use a dremel to reshape the needle also?


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## Alfieboy (Dec 26, 2018)

That dispersion plate looks different to a "normal" one with 6 holes rather than 4

If you look at the espresso shop they seem to be commercial ones although it says suitable for a Classic in the Amazon write up - also there are some reviews that refer to the same leaking issue


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## newdent (Feb 20, 2021)

Bellybud said:


> Been a while since I last updated.
> 
> I bought a pressure gauge to check what I had adjusted the OPV to but I've now encountered a new problem, when the pressure exceeds 4 bar it starts leaking around the portafilter. I had put the filter holder gasket in upside down (duh) it it is still leaking after correcting... I had recently replaced it with the linked product below but I can see some reviews where it didn't seal the portafilter correctly. Should I buy another gasket seal from The Espresso Shop or could there be a different issue?
> I've spent way more than planned in doing sorting this machine 😭
> ...


 Which gasket do you have in there? The blue silicone one by cafelat works great but do you need to bother with the new dispersion plate? Adds a fair amount on to the cost.

For cleaning up the tip of the steam valve, putting it into a drill and then touching it against some fine fans paper works. I used 600 wet and dry as that's what I had lying around. Wrap in some tape or similar before putting into the drill to avoid marking the brass.


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## Bellybud (Nov 2, 2021)

Uncletits said:


> That dispersion plate looks different to a "normal" one with 6 holes rather than 4
> 
> If you look at the espresso shop they seem to be commercial ones although it says suitable for a Classic in the Amazon write up - also there are some reviews that refer to the same leaking issue


 As it is leaking around the portafilter when attached is it likely to be the silicone seal that is causing the leaking though?



newdent said:


> Which gasket do you have in there? The blue silicone one by cafelat works great but do you need to bother with the new dispersion plate? Adds a fair amount on to the cost.


 The gasket it came with was very firm and cracked. The shower plate holder was also fairly grim even after the descale which is why I replaced the set.



newdent said:


> For cleaning up the tip of the steam valve, putting it into a drill and then touching it against some fine fans paper works. I used 600 wet and dry as that's what I had lying around. Wrap in some tape or similar before putting into the drill to avoid marking the brass.


 I shall certainly try this, probably closer to Christmas due to where I am atm... Unless I can borrow the dremel from work to access the part.


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## newdent (Feb 20, 2021)

Bellybud said:


> As it is leaking around the portafilter when attached is it likely to be the silicone seal that is causing the leaking though?
> 
> The gasket it came with was very firm and cracked. The shower plate holder was also fairly grim even after the descale which is why I replaced the set.
> 
> I shall certainly try this, probably closer to Christmas due to where I am atm... Unless I can borrow the dremel from work to access the part.


 It's only the silicone gasket that stops it leaking. Are you using the stock portafilter?

Are you certain the leak isn't coming from the boiler/group head junction?


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## Alfieboy (Dec 26, 2018)

Bellybud said:


> As it is leaking around the portafilter when attached is it likely to be the silicone seal that is causing the leaking though?
> 
> The gasket it came with was very firm and cracked. The shower plate holder was also fairly grim even after the descale which is why I replaced the set.
> 
> I shall certainly try this, probably closer to Christmas due to where I am atm... Unless I can borrow the dremel from work to access the part.


 A file with one plain edge will be the stock tool to do this


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## Bellybud (Nov 2, 2021)

newdent said:


> It's only the silicone gasket that stops it leaking. Are you using the stock portafilter?
> 
> Are you certain the leak isn't coming from the boiler/group head junction?


 Yes it is the stock portafilter. It seals properly when I use the backflush 'blank' but it leaks when using the OEM baskets and the IMS precision basket that I bought.

The boiler/grouphead junction is screwed fairly tightly, I removed it earlier to clean and get the gasket out to turn the right way. So I don't think that it is that, though I'm not sure how I could see as I need to cover it to build the pressure for the leak to occur. Either way, the gasket/portafilter connection connection should seal that in as well anyway, right?


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## newdent (Feb 20, 2021)

Bellybud said:


> Yes it is the stock portafilter. It seals properly when I use the backflush 'blank' but it leaks when using the OEM baskets and the IMS precision basket that I bought.
> 
> The boiler/grouphead junction is screwed fairly tightly, I removed it earlier to clean and get the gasket out to turn the right way. So I don't think that it is that, though I'm not sure how I could see as I need to cover it to build the pressure for the leak to occur. Either way, the gasket/portafilter connection connection should seal that in as well anyway, right?


 I don't think we're on the same page here regarding the boiler/group head junction location. That junction is inside the case and seals with an o ring. I had a leak on the boiler once and it runs down everything, goes through the hole in the case and then runs around the portafilter so it's quite easy to think the leak is coming from the group gasket - I certainly did to begin with!

Though you say it only seals with the blind basket, that's very strange. You've got the square edged side of the gasket coming into contact with the basket? Maybe you're locking the PF in too tight or not tight enough. Are you making sure to wipe any of grounds off the top of the basket? Not really sure what else to suggest! My aftermarket PF did this sort of behaviour but turns out that whilst the PF fit, it wasn't quite the right size, so I'm using the stock one now.


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## Alfieboy (Dec 26, 2018)

Did you try the old shower plate back onto it as the new one looks different to the standard one? 6 holes as opposed to 4


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