# Gaggia Classic light not going off when I pre flush.



## urbanbumpkin (Jan 30, 2013)

Hi, hope someone can enlighten me as to what might be happening with my Classic.

My usual routine over the last few months has been to

Let my Classic to warm up for 30 mins.

Do a pre flush before fitting a portafilter, brew light goes off.

Then hit the brew button as soon as the light goes back on for shot.

However over the last week or so the lights not been going off when I do the pre flush.

I haven't changed any other part of the routine, the pre flush has always been about an 1oz ( usually just under.

I've done the usual backflush with pulcaff but this has made no difference. The light does go on and off at other times but not after the pre flush.

Any suggestions as to what's going on?

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## Kyle548 (Jan 24, 2013)

If you run a lot more though it, does it go off?


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## urbanbumpkin (Jan 30, 2013)

Kyle548 said:


> If you run a lot more though it, does it go off?


I've run for about 1.5oz and it hasn't gone off although that was before I'd cleaned and back flushed it. I'll give it a try tomorrow. The pre flush only used to be about .5 - .75 before.

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## Kyle548 (Jan 24, 2013)

When you get it up to temp tomorrow measure the time it take the boiler to cycle on and off without flushing it.

Then when the light cycles on, time how long it takes to cycle off and measure the shot output volume while flushing.

Then from cycling off how long it takes to cycle on again.

Do you have any way of measuring temps?

When I do a cup preheat flush for about an ounce or more the light doesn't flick off for a little while, so I doubt you have a problem though.


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## urbanbumpkin (Jan 30, 2013)

Kyle548 said:


> When you get it up to temp tomorrow measure the time it take the boiler to cycle on and off without flushing it.
> 
> Then when the light cycles on, time how long it takes to cycle off and measure the shot output volume while flushing.
> 
> ...


So let me get this straight.

"measure the time it take the boiler to cycle on and off without flushing it. " So get up to temp and measure the time between the light off then on again?

"Then when the light cycles on, time how long it takes to cycle off and measure the shot output volume while flushing." So I'll need to hit the brew button when the light goes back on and time how long it takes for the light to go off and measure the out put.

And then basically how long it takes for the light to go back on again.

I have a thermometer that I can measure the water temperature in the shot glass. Not sure if that will give an accurate indication?

My light also didn't go off straight away after the pre flush. There used to be an approx 20 secs delay light go off, then about 10-15 secs and the light would go back on.

Thanks for the help will feed back results.

Maybe I've got faster with my routine or just more impatient!









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## Kyle548 (Jan 24, 2013)

I have noticed that since changing to the classic I have needed to adjust my routine quite a lot.

So probably it's just a case that, like you say, you are getting your hand in.

The only thing I think you really need to worry about is if the brew water is too hot or too cold really.

The tstat has a lot of swing before it clicks off and on anyway, so you can't guarantee that it will click on or off at the same time anyway, if you are running water; adding cold water is going to shock the boiler to a colder temp than if you just let it cool.


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## El carajillo (Mar 16, 2013)

Stating the obvious when the light is on, the M/ch is up to temperature. When it is off the heating element is working. When it does not come on after a flush it could be that the T/stat is still sensing the excess heat from the metal work. It could be that the BREW stat is failing/faulty. It is a cheap component and very easy to replace. (If you replace it DO NOT over tighten)


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## urbanbumpkin (Jan 30, 2013)

El carajillo said:


> Stating the obvious when the light is on, the M/ch is up to temperature. When it is off the heating element is working. When it does not come on after a flush it could be that the T/stat is still sensing the excess heat from the metal work. It could be that the BREW stat is failing/faulty. It is a cheap component and very easy to replace. (If you replace it DO NOT over tighten)


Thanks for this. How do know when the t/stat is faulty? What's the best way to rule it out either way?

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## Kyle548 (Jan 24, 2013)

The brew temp.

There is about a 10C swing, so, taking into account heat loss, when you pull a shot on a hot machine into a warmed cup, you should get about 90ish.

If its way hotter, broaching 100, then it's too high and if its way lower, say less than 85, it's too low.

Even with a pid set to 102, you get brew water at the group head in the 90 range. (I think the tstat is set to something like 100?)

Don't pull for too long though, as cold water will eventually be put into the cup.

Say about 1 ounce is maybe a good starting point.

It's important your machine is up to temp, because it will leach heat.

Especially since the shower plate isn't brass.

Same goes for the cup, use a nice thick espresso cup.


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## urbanbumpkin (Jan 30, 2013)

Thanks for all of the help again.

Ok I did a quick check tonight.

The Thermometer I have isn't up to much (and is in Fahrenheit) so I've not bothered with that.

Time in between cycles once its warmed up is approx 10secs.

10 secs from light on to light off, 3oz in volume produced. It took about 35 secs for the light to come back on.

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## Kyle548 (Jan 24, 2013)

urbanbumpkin said:


> Thanks for all of the help again.
> 
> Ok I did a quick check tonight.
> 
> ...


That doesn't sound too weird.

Are you noticing any difference in the cup?

If your espresso is still coming out how it usually comes out, without any unusual sour or bitter accents, then I would expect that you have nothing to worry about and your tstat is fine.

If you are really concerned about it though, you can get a new one for like £15 and the instillation is a 5 or 10 min job, as long as you don't get annoyed with fidgety screws.

http://www.ebay.co.uk/itm/Gaggia-Coffee-Maker-Machine-Thermostat-107degC-/160746481112?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BIEW%252BFICS%252BUFI%26otn%3D21%26pmod%3D160524638803%26ps%3D54

If you do install a new one though, your machine might act a little differently, since each tstat is a little different.


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## urbanbumpkin (Jan 30, 2013)

Thanks Kyle548. There's no real difference from what I can tell although it started about the same time as I was trying a new beans.

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## Kyle548 (Jan 24, 2013)

If you still feel something's up in the coming month, after I finally install my pid, you can have my tstat.


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## El carajillo (Mar 16, 2013)

Try Mark at Gaggiamanualserve on this forum for knowledge/parts:good:


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## urbanbumpkin (Jan 30, 2013)

Kyle548 said:


> If you still feel something's up in the coming month, after I finally install my pid, you can have my tstat.


Thanks Kyle very good of you

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## Glenn (Jun 14, 2008)

Unless you are drawing a lot of water through the group the light should stay on.

Only when the boiler is being heated will the light go off


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