# Gaggia Overheating



## tiipoto (Oct 6, 2010)

We have a Gaggia Classic, 2 to 3 years old, which is well used and regularly descaled.

The machine has suddenly started overheating. It seems that the water is virtually boiling.

When operating the main head to make coffee, steam plus very hot water comes out.

I assume that there is a thermostat on the boiler, which may have failed.

Can anyone suggest what could be wrong and how to fix it.

Very loathe to send to Gaggia service.


----------



## ChiarasDad (Mar 21, 2010)

It does sound as though your thermostat has failed. You can purchase a new one for not terribly much money* and install it yourself. This is a little bit fiddly but honestly not really hard; perhaps a 20-minute job if you're slow like I am.

My thermostat (on a Classic of similar age) went bad a few months ago (too cold rather than too hot in my case), and I opted for a PID kit instead of a conventional thermostat. The PID kit I chose was American, about £100 plus taxes and duties, and was a very nice addition to the Classic. You certainly don't need to go that route, but in my case it was a fun project as long as I was going to have to open up the machine anyway.

*I believe members LeeWardle and gaggiamanualservice.com are able to supply them.


----------



## Schnorbitz (Jul 5, 2009)

http://www.espressoparts.co.uk/gaggia.asp?img=119

Here you go (although you may want to support forum members listed above). Very easy job to replace the thermostat (it's the one one the left hand side of the boiler). You want the 107C version, although I replaced mine with the 100C as tests showed the water to be too hot with my 107C stat. The 145C stat is for steaming.


----------



## LeeWardle (Nov 16, 2008)

Yeah, 100 is the one. I'd go with espresso parts, I wouldn't be able to do it much cheaper tbh!

Lee


----------



## tiipoto (Oct 6, 2010)

Many thanks for your help.

I have emailed Espresso Parts for a price plus delivery, as we are in France.

Out of interest, what is a "PID" kit ?


----------



## ChiarasDad (Mar 21, 2010)

A PID is an advanced temperature control. Unlike the stock thermostat, it is settable to whatever temperature you wish (within reason), and it maintains that temperature within a degree or so (again unlike the stock thermostat which lets the temperature bounce about quite a bit).

The benefits are that you can tune your temperature to the coffee you're working with, and that one source (out of, admittedly, many) of shot-to-shot inconsistency is very substantially reduced.

The kit I purchased is this one: http://www.auberins.com/index.php?main_page=product_info&products_id=35

A lengthier description of PID retrofitting and its history is here: http://www.gizmodo.com.au/2010/07/tickling-miss-silvia-mark-frauenfelder-hacks-coffees-god-shot/


----------



## dugs36 (May 12, 2020)

Hi all. I had the same issue and replaced the thermostat. For a while to returned to normal but after about a month the problem has returned. Any thoughts?


----------



## ratty (Sep 22, 2019)

A member of this forum MrShades makes and supplies PID's for the Gaggia Classic.

Many members have bought and are using them successfully (I had one too before selling machine) Cost is £94

The instructions are very comprehensive and no electrical knowledge is really required if you follow the instructions carefully.

He is also just a message away and can help sort out any problem that may occur during/after assembly.

The PID is for pre 2015 models I believe. He also has some equipment for post 2015 models


----------



## dugs36 (May 12, 2020)

Thanks @ratty

I've messaged @MrShades and hope to hear back soon. Def want to get the PID on the go!


----------



## PeeJayBee (May 25, 2020)

Ooh, can I hijack this thread as I have the same overheating issue.

Is it definitely the 100º one like... (it doesn't mention Gaggia Classic)

https://www.theespressoshop.co.uk/en/Gaggia-Contact-Thermostat-100C-M4---WGADM1561/m-2574.aspx

whereas the 107º one says it's for the Classic

https://www.theespressoshop.co.uk/en/Gaggia-Classic-Boiler-Water-Thermostat-107C-M4---DM1168/m-2573.aspx


----------



## NitJay (May 18, 2020)

Glad I'm not the only one with this problem.

I'm also going with the @MrShades pid kit to try and resolve permanently 👍


----------



## L&R (Mar 8, 2018)

107 is the right thermostat for classic!


----------



## Alain Kapper (May 30, 2020)

Hi all.

First time i am posting anything here, or on any fora for coffee lovers. Hope you don't mind me hijacking this thread.

i had the same issue and replaced the thermostat. Unfortunately, i tightened it too much when I screwed it back on, so much so that the screw snapped in the boiler. I glued it back on but in retrospect, i think i have made more a mess than helped with the situation. I fitted back all the parts but as i switch on the machine, home fuse keeps on blowing.

Could the broken thermostat be the cause of this? If so, ill order a new boiler and a thermostat.

thanks

Alan


----------



## ratty (Sep 22, 2019)

Just buy a new thermostat to start with. They're not expensive and no major strip down involved. Go very easy on the tightening!



Alain Kapper said:


> Hi all.
> 
> First time i am posting anything here, or on any fora for coffee lovers. Hope you don't mind me hijacking this thread.
> 
> ...


----------



## Alain Kapper (May 30, 2020)

Thanks. I have managed to remove the broken screw and will purchase the thermostat. Cheers



ratty said:


> Just buy a new thermostat to start with. They're not expensive and no major strip down involved. Go very easy on the tightening!


----------

