# Blockage? Bubbling back into reservoir



## planetf1 (Feb 7, 2010)

I have a sylvia (V2 I think) and am getting an issue where water/steam is bubbling BACK into the water reservoir

The temperature of the water is hot, but I don't think it's just thermostat failure, more likely a blockage or leak

The flow is far too low out of the head.

I've cleaned so far with puly caff/blanking plate, but the blockage is clearly further back - even here it doesn't look as if the pressure 'builds' as much as normal for the back flow

I intend to use some descaler tonight or tomorrow night.

Any suggestions as to the likely cause? Blockage? Limescale?


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## ashcroc (Oct 28, 2016)

Video with sound would help greatly. From your description it could just be the OPV.


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## planetf1 (Feb 7, 2010)

Ok will try and take some video.

It does seem a reasonable explanation - suggesting a blockage elsewhere.

So far cleaning (poly) and descaling (dezcal) hasn't addressed.

Yet to remove/clean screen and/or dismantle.

Thanks.


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## planetf1 (Feb 7, 2010)

Ok here's the video - after my attempt at descaling/cleaning & with the shower screen removed (for cleaning)






* At the beginning you'll hear and see the steam bubbling back into the reservoir. The pipe is hot (and the reservoir ends up heating up)

* Initially I had the blanking filter in (from my cleaning attempts) - notice there's very little water coming back to the drain area (I'd removed the tray for cleaning so just as well. lol!)

* when I switch the brew on you'll notice low water flow

* The 'hot water' button is dispensing water well, with a good pressure and temperature

I'm guessing the next step is to start physically dismantling. I've removed the lid before in order to reset a trip on the boiler.. but that was a few years back after it had run dry.. so not directly related. I'm not aware of the workings of the over pressure valve - other than from it's name... I've done more work on an old gaggia so vaguely get the principles.

I tend to try and clean the machine every month or so - probably not often enough, and descale has only been every 6 or so

The water flow has been reducing significantly in recent months

The machine is starting to age - indeed I fancied a new machine over black friday but phone won. Intrigued if you think this is recoverable or time to move on, and if so what next .. likely bean to cup (Sage? can't afford the twin though)

Sincere thanks

Nigel.


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## L&R (Mar 8, 2018)

I would clean the OPV manually in descaler. Maybe the 3-way valve needs some attention too. Just open these two valves and give them a good cleaning. This machine can always be fixed despite the age.


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## ashcroc (Oct 28, 2016)

The OPV should be closed before starting a shot so is the obvious place to look. You'll need a portafilter pressure gauge* to reset the OPV after (static pressure is about 1 bar higher than fliwing pressure so set to 10 for 9 bar during shot).

The good news is the parts in a Silvia are similar to those in a Classic so your previous experience will help.

*Link just for example. No experience of this particular gauge or seller.


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## planetf1 (Feb 7, 2010)

Thanks,

I removed the top of the machine and can see what appears to be the solenoid valve (large brass 3 way piece to right of boiler)









The nuts seem stiff.

For the nut between the boiler and the valve, do I rotate the middle nut? Which way?

I presume the OPV is the part towards the left of the side picture, with the nut to the right next the solenoid the one to remove first, then try cleaning & perhaps disassembling valve

The other picture points downwards - I was wondering what I need to check'clean if this isn't the problem, but I guess then we're into splitting the boiler and the corresponding risk & need for a new seal?

Thanks


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## L&R (Mar 8, 2018)

This on the right top of the boiler is OPV to remove it you will need a spanner 20mm or a monkey wrench. You will need a pressure gauge afterwards to calibrate the brew pressure. Don't need to remove the whole body valve only the cap with spring and the piston. Check out my thread for pressure adjustment of Slivias.


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## planetf1 (Feb 7, 2010)

L&R said:


> This on the right top of the boiler is OPV to remove it you will need a spanner 20mm or a monkey wrench. You will need a pressure gauge afterwards to calibrate the brew pressure. Don't need to remove the whole body valve only the cap with spring and the piston. Check out my thread for pressure adjustment of Slivias.


thanks

Any tips on removing the opv (and ideally 3way).

The OPV has two nuts. I've been unable to release with an adjustable wrench, I also thought I'd try removing the 'sheath' over the pipe that goes back to the reservoir on the opv, but whilst the sheath as a clip to hold in place, it seems as if the plastic pipe beneath it is pretty much moulded on to the opv. I'm unsure if that's normal, it's melted, or I'm not pulling hard enough? The reason I was wondering was to see if I could get a socket over the nut, though tbh it looks as if the metal body is too long.

Is it definately a 20mm? I have a 19, 22 & adjustable but can't safely get the leverage with either. If it is I will order/purchase a 20 and try again.

Before I do, any recommendations on clean/reset opv without removal? I'm currently retrying descaling, and allowing the opv bubble back in the hope the descaler might allow the valve to release

Additionally i've been unable to remove the opv either. I do have a 15mm spanner which fits the nut that sits between the boiler and the 3way. I'm unsure which way to turn it (I assume towards me) but don't seem able to release it and am worried about putting too much stress on the mountings of the boiler. Any tips here? Better when boiler is hot perhaps (I've not tried that yet)?

Many thanks for any tips!

Nigel.


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## planetf1 (Feb 7, 2010)

Another observation:

* With the brew head blanked off, the flow & pressure coming back through the return pipe is pretty decent - finger over = squirting everywhere, so that's a good sign the pump is fine

* With the brew head open - there's a decent flow of water too - with a small amount coming back through the return pipe - again no surprise as there is little resistance to the flow through the head. This suggests there isn't a significant blockage

* After brewing a small amount does come through the 3way valve to the drip tray - not as much as normal, but this is because more is going through the return pipe

Just thought I'd mention as I think all this evidence does point to the OPV & hopefully little else


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## planetf1 (Feb 7, 2010)

I've now managed to remove the part of the opv valve where the pipe attaches to go back to the reservoir (2 paired nuts) and am descaling. Inside is just a spring. It doesn't look too bad but is soaking fior a while.

i've yet to be able to remove the main Y shape by the boiler - so will try cleaning what I have first

i presume it's the spring section that is more likely to stick?


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## planetf1 (Feb 7, 2010)

've now managed to remove the part of the opv valve where the pipe attaches to go back to the reservoir (2 paired nuts) and am So I've managed to now loosen the main opv from the boiler (the centre nut is still right), but the nut attaching the braided pipe to the next stage is secured very solidly.

A 12mm is too small, a 13mm has too much play, and with a softish nut just gouges it with no motion. (a 1/2" is slightly too small also fyi).

*Does anyone know what size this nut is meant to be?*

So the two options now seeem to be

a) see if the part I've removed and/or adjustment will address the issue (I'm doubtful since I presume there's some plunger in the body that the spring I removed is pressing against, with adjustment provided by the but.. so if it was stuck before it is likely still stuck?)

and if that fails:

b) try to dismantle further to release the other end of the braided pipe instead, so that the entire OPV valve may be removed

tips & alternatives are very welcome. Seeing what needs to be done isn't too hard but there's certainly a knack to the mechanical execution!

Thanks

nigel.


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