# Silvia boiling



## Paulb (Apr 11, 2018)

Hi

i have a V1 Silvia, it has been used daily for almost 15 years and it has been faultless...... up to now. 
Recently I have noticed when the thermostat light turns off the water boils and it flushing back through the expansion pipe. It is still making good coffee and the steam pressure is good. 
Apart from this boiling it appears to be working well. 
Any ideas what could be causing this.

Another thing which could be related is I was steaming milk for 6 coffees and on the last coffee the thermostat tripped off and I had to open it up to reset it. This has happened 2 or 3 times since I purchased the machine so I'm not sure if it is related.

I have checked the temp of the espresso shots and it appears to be coming out at 80 degrees so that seems ok to me. But if water is boiling in the expansion pipe it must mean that water in the boiler must be 100...

Any ideas?

thanks

p


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## Nikko (Aug 20, 2014)

Not very clear what you mean. Are you saying that when pulling a shot the outflow from the pressure relief valve boils but the coffee tastes ok? If it tastes ok then unlikely to be a faulty thermostat but these are not super accurate and the thermostat switch off temperature can be above 100C. If in doubt replace the thermostat.


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## Paulb (Apr 11, 2018)

My main query is why is it suddenly boiling through the overflow?

is the problem more likely to be a thermostat or could it be a gasket or valve not functioning properly and allowing water out?


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## El carajillo (Mar 16, 2013)

If you steamed milk for 6 coffee's without refilling the boiler it has probably Knacked the stat and you are lucky it has not knacked the heating element =steamed it DRY ???


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## Nikko (Aug 20, 2014)

Paulb said:


> My main query is why is it suddenly boiling through the overflow?
> 
> is the problem more likely to be a thermostat or could it be a gasket or valve not functioning properly and allowing water out?


 The whole point of the pressure relief valve is to maintain 9 barg by letting water out. So not a malfunction.


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## Paulb (Apr 11, 2018)




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## Paulb (Apr 11, 2018)

El carajillo said:


> If you steamed milk for 6 coffee's without refilling the boiler it has probably Knacked the stat and you are lucky it has not knacked the heating element =steamed it DRY ???


 Good point!!



Nikko said:


> The whole point of the pressure relief valve is to maintain 9 barg by letting water out. So not a malfunction.


 But this never happened before so something must be wrong. 
My gut feeling is the thermostat. 
Anyone recommend a site for rancilio parts?


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## ashcroc (Oct 28, 2016)

Paulb said:


> But this never happened before so something must be wrong.
> My gut feeling is the thermostat.
> Anyone recommend a site for rancilio parts?


The Espresso Shop sell Silvia parts. Would probably be worth getting a service kit (be careful to get the right one for your machine) which includes new stats.


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## shadow745 (Apr 29, 2012)

Could be thermostat related, but could easily be the OPV is clogged/sticking open, allowing the hot water to be sent back to the water reservoir. Actually had this to happen, took the valve apart, cleaned it, etc. and was fine afterward.


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## Nikko (Aug 20, 2014)

The purpose of the opv is to send hot water back to the reservoir. What are the indications that the water sent back is boiling? Some bubbles in the tube is normal.


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## shadow745 (Apr 29, 2012)

Can't agree as technically the OPV 'should' only be sending tank temperature water back to the tank once preset pressure has been reached if it's working as designed. If hot water from the boiler is making it back to the tank then the OPV should be cleaned/rebuilt to prevent that as well as being sure the thermostat(s) are properly functioning.


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## Nikko (Aug 20, 2014)

shadow745 said:


> Can't agree as technically the OPV 'should' only be sending tank temperature water back to the tank once preset pressure has been reached if it's working as designed. If hot water from the boiler is making it back to the tank then the OPV should be cleaned/rebuilt to prevent that as well as being sure the thermostat(s) are properly functioning.


 Got a bit muddled up. You are absolutely correct.


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