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Thread: Help me resuscitate my Grimac - not heating

  1. #1
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    Unhappy Help me resuscitate my Grimac - not heating

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi folks,

    I'd love some help reviving my Grimac Mia. The boiler has stopped heating. I can't afford to have it repaired and I like pulling things apart (whether I'm any good at it or not is another question...). If anyone can help me at least diagnose the problem or isolate some likely culprits I'd be so grateful! Hate to have to lose her.

    Here's what I can tell you - the machine turns on and buttons on the control pad light up and I can get (cold) water pumped through the group head. Nothing from the steam wand or the hot water outlet (although I can hear it clicking on). Usually when I turn it on I hear a pump - presumably from the water reservoir to the boiler, which now I don't hear. The reservoir trip button thing (to let the machine know there's water) doesn't seem broken or stuck.

    Here's a parts diagram for the machine if it helps - https://coffeemachineparts.in/hikash...ia-spare-parts

    Please join me on my coffee machine repair journey! I'd really appreciate any help.

    Thanks heaps.
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  2. #2
    Senior Member matth3wh's Avatar
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    Hi Charlakins. How long since it was last serviced? And do you use filtered water?

    Hopefully it is just the heating element that has died on you.

    On my last machine I had a similar sounding problem - all lights working and pump working / pumping through tank water fine but could not hear it heating. Presumably your auto fill has already filled the boiler and doesn't need to fill any more. Do you have a pressure gauge telling you anything happening? Steam and hot water taps won't work without heat and pressure building up.

    I took it to a shop for an inspection/ quote which cost about $70-$80 and then based on that information I did the repair myself. Nothing to lose given the price they wanted to fix it.

    They quoted I think around $800-$900 - no doubt because of labour charges and who knows if the boiler / element is going come off easily or if some boiler piping might be weak and break along the way or your boiler is filled with scale chunks...

    In the end DIY fix cost about $100 and a fair amount of time carefully documenting as pulling apart machine. Diagrams and camera comes in handy. :-)

    Anyway, have you had an inspection to give you any clues?

    Hopefully you can be back in the coffee action again in the not too distant future. Meanwhile get the aeropress out.

    #insertelectricaldisclaimertonotelectrocuteyoursel f.
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  3. #3
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    Great thoughts, thanks

    Thanks so much, that's really helpful.

    Last serviced too long ago (24 months?) but we do use filtered water. Nothing registering on the pressure gauge. Sounds like the heating element is the primary suspect, although I wonder if it couldn't be the pump from the water reservoir to the boiler? (I presume there are two pumps - one reservoir to boiler one boiler to group head? If there are two only the latter is working). Maybe the boiler isn't heating because it doesn't have water in it because the pump's broken... or would it attempt heating anyway?

    My father in law is a sparky so I'll enlist his help to pull it apart and test circuits. The one useful website I found was a comprehensive diagram of what bits go where, I'll take your good advice and take photos too. One repair place have offered a free diagnosis and quote so it will be interesting to hear what they say.

    Will let the forum know how I get on. Thanks again for your experience and thoughts. It's so hot in Brisbane right now I could almost forego the coffee for a while... (not really).

    Charla



    Quote Originally Posted by matth3wh View Post
    Hi Charlakins. How long since it was last serviced? And do you use filtered water?

    Hopefully it is just the heating element that has died on you.

    On my last machine I had a similar sounding problem - all lights working and pump working / pumping through tank water fine but could not hear it heating. Presumably your auto fill has already filled the boiler and doesn't need to fill any more. Do you have a pressure gauge telling you anything happening? Steam and hot water taps won't work without heat and pressure building up.

    I took it to a shop for an inspection/ quote which cost about $70-$80 and then based on that information I did the repair myself. Nothing to lose given the price they wanted to fix it.

    They quoted I think around $800-$900 - no doubt because of labour charges and who knows if the boiler / element is going come off easily or if some boiler piping might be weak and break along the way or your boiler is filled with scale chunks...

    In the end DIY fix cost about $100 and a fair amount of time carefully documenting as pulling apart machine. Diagrams and camera comes in handy. :-)

    Anyway, have you had an inspection to give you any clues?

    Hopefully you can be back in the coffee action again in the not too distant future. Meanwhile get the aeropress out.

    #insertelectricaldisclaimertonotelectrocuteyoursel f.

  4. #4
    Senior Member noidle22's Avatar
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    Could also be a broken pressurestat microswitch, I've seen a few Mia's with this problem.

    You can easily test this with a multimeter. With the machine off and unplugged, continuity test the two wires where they attach to the microswitch. There should be continuity. If there is no continuity, then the switch is bad.

    A new switch can be sourced on RS Components, it's a Cherry D45X and is around $5.
    matth3wh likes this.

  5. #5
    Senior Member matth3wh's Avatar
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    Quote Originally Posted by noidle22 View Post
    Could also be a broken pressurestat microswitch, I've seen a few Mia's with this problem.
    ...
    A new switch can be sourced on RS Components, it's a Cherry D45X and is around $5.
    Good point Noidle22. Hopefully for Charla it turns out to be failed pressurestat.

    Quote Originally Posted by Charlakins
    (I presume there are two pumps - one reservoir to boiler one boiler to group head? If there are two only the latter is working). Maybe the boiler isn't heating because it doesn't have water in it because the pump's broken... or would it attempt heating anyway?
    Depends on machine configuration and what your lights are supposed to indicate. Most have a power light for basic on/off. Sometimes a light sayings its heating. Some a light saying water level is good to go. Some lights will be on when tank water level is good and then go out when water level needs to be topped up. Some manufactures have that water light the other way around... i.e. the indicator light goes on when water level is low - and heating element shuts off. Some older machines might not and then heating element on with no water to heat up would be bad.

    Your parts diagram link mentions a sonda per autolivello - water probe autoleveller. Might be worth checking to see if it's not scaled up.

    On the heat exchange (HX) machines, most have one pump which fills the boiler and also pumps water from the tank through the HX pipe to the group head. In a lot of cases there are water level probes going down in to the boiler to tell the pump to fill the boiler from the tank. Pressurestat should tell the heating element to switch off when the boiler reaches a set pressure level.

    Charla, in your case the pump seems to be working which saves some more $

    Hope you get your machine fixed up and working again (without breaking the bank). :-)

  6. #6
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    You guys are amazing, thank-you so much.

    I'll let you know how I get on. Looking forward to understanding the inner life of my machine.

    Charla



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