logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda

Bosch CTES32 Coffee Machine: Cold Water Issue, Possible Heater Damage?

kesy1 7827 14
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
Report a violation of the law
| New topic
  • #1 16637292
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    Hello,
    I have a problem with the Bosch CTES32 coffee machine, namely the coffee machine does not heat up, and everything else works properly. When making coffee, the coffee machine grinds the beans, then releases the water only cold, when you try to release hot water, the message Water heating up appears on the display and after a while the machine returns to its initial state. Maybe someone will advise what the problem is or how to check if the heater is damaged. I have the coffee machine open, if anyone needs it, I can make photos.
    best regards
  • ADVERTISEMENT
  • #2 16640889
    nioop

    Home appliances specialist  
    Posts: 3359
    Help: 503
    Rate: 3319
    Please do not pick me up wrong, but it seems to me after the post that you do not have the skills to use a multimeter?

    Because without it, you can't do it ...

    Most often one of the thermal fuses is damaged, but it happens when the electronic board is damaged.
    Company Account:
    Kawa i Naprawa - Serwis AGD
    Powstańców Śląskich 63, Warszawa, 01-355 | Company Website: https://www.kawainaprawa.eu
  • #3 16641287
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    I warmly welcome,
    You're right, I'm not an eagle in this field, but if I measured the heater correctly, it showed infinity on the meter, so it will probably be replaced, I'm still wondering about the very low voltage on the heater (the voltage is only a few volts and here you are right that it could also be damaged) the tile is subject to check only) Regards

    Added after 3 [minutes]:

    I will add that the voltage at the output from the switch is 240V and this also enters the board and the output from the board is just a few V, as I wrote earlier
  • #4 16642116
    nioop

    Home appliances specialist  
    Posts: 3359
    Help: 503
    Rate: 3319
    This is where this barrier comes in.

    Unplug the wires that lead the current to the heater and then measure how much V comes ...
    Of course, the heater's thermal fuses must be taken into account. If it turns out that one of them is damaged, it is also recommended to replace the ntc sensor, which is responsible for maintaining the right temperature.
    I just can't remember whether there is direct or alternating current going there ...
    If it turned out from this map that there is no need to check the relay on the electric plate in the first relationship, which is responsible for switching on the heater.
    Company Account:
    Kawa i Naprawa - Serwis AGD
    Powstańców Śląskich 63, Warszawa, 01-355 | Company Website: https://www.kawainaprawa.eu
  • #5 16642151
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    Hello, I ordered the entire heater. I will try to replace it, let's see if something changes
    best regards
  • ADVERTISEMENT
  • #6 16647492
    bosman116
    Level 19  
    Posts: 337
    Help: 23
    Rate: 150
    kesy1 check the fuses at the heater are in order. If one of them is damaged, there is a high probability that it will fry it again after inserting a new heater.
  • #7 16647520
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    Hello, I'd love to do it but I have no idea how to go about it ;) maybe some hint which fuses are and how to check them Bosch CTES32 Coffee Machine: Cold Water Issue, Possible Heater Damage?
  • ADVERTISEMENT
  • #8 16647558
    bosman116
    Level 19  
    Posts: 337
    Help: 23
    Rate: 150
    We know how to measure ...? Bosch CTES32 Coffee Machine: Cold Water Issue, Possible Heater Damage?
  • #9 16648023
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    something there sometime ;) they need to be removed somehow and we measure with an ohmmeter, of course?
  • ADVERTISEMENT
  • #10 16652690
    bosman116
    Level 19  
    Posts: 337
    Help: 23
    Rate: 150
    Climb not necessarily, but that's right with an ohmmeter - Uncle Google will help.
  • #11 16652847
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    Hello, I measured the fuses and you were right one (the one on the power supply) is damaged, the other is ok (about 1.5 ohms). As for the heater, measured outside the fuses is also ok (about 35 ohms). I have already ordered the heater, but now I'm afraid to insert it, since there is a chance that it will fry it right away. Where to look for the problem now ???
    best regards
  • #12 16652867
    bosman116
    Level 19  
    Posts: 337
    Help: 23
    Rate: 150
    When you insert a new heater and the coffee maker, after inserting the plug into the contact, it will heat it up, i.e. that the power module still has a short circuit in the system. You can check it on the old heater by strapping the wires, omitting the fuse. Just be careful that they do not touch the metal parts of the coffee machine.
  • #13 16655653
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    Hello, can anyone advise you on how to remove this coffee container. I can't cope with the disassembly of the top casing of the TES50321RW / 12 coffee machine and without it the ntc sensor cannot be replaced. maybe someone knows some other way Please help
  • Helpful post
    #14 16680123
    bosman116
    Level 19  
    Posts: 337
    Help: 23
    Rate: 150
    You need to empty the coffee bean container, unhook the 2 optical presence sensors from the hooks, bend the hooks around the grinder and lift the whole thing up. Of course, the casing around the machine must be removed. It will be much easier.
  • #15 16681885
    kesy1
    Level 10  
    Posts: 37
    Rate: 58
    Thank you for your help. The coffee machine has been repaired, the heater has been replaced and so far everything works
    best regards
| New topic
Report a violation of the law

Topic summary

✨ The Bosch CTES32 coffee machine is experiencing a cold water issue, where it grinds beans but only dispenses cold water. Users suggest checking the heater and thermal fuses, as a damaged thermal fuse could prevent the heater from functioning properly. The original poster measured the heater and found it to show infinity, indicating a potential failure. After further testing, a damaged power supply fuse was identified, and a new heater was ordered. Users provided guidance on measuring fuses and suggested caution when replacing components to avoid further damage. Ultimately, the heater was replaced, resolving the issue.
Generated by the language model.

FAQ

TL;DR: Bosch CTES32 not heating? One user measured 35 Ω on the heater and found a blown thermal fuse; replacing the heater fixed it. “It will be much easier.” [Elektroda, bosman116, post #16680123]

Why it matters: This FAQ helps DIYers quickly diagnose cold-water output and avoid frying a new heater in Bosch CTES32/TES50321RW machines.

Quick Facts

How do I quickly confirm if my Bosch CTES32 heater is actually bad?

Unplug the machine. Disconnect heater leads and measure resistance across the element. A healthy unit reads around 30–40 Ω. If it reads open (infinite), the element or a series thermal fuse is blown. Check the two inline thermal fuses individually with an ohmmeter before ordering parts. Replace any open fuse and inspect the NTC sensor while inside. [Elektroda, kesy1, post #16652847]

Why is my machine dispensing only cold water but otherwise working?

Grinding and pumping can work while the heater circuit fails. Forum diagnostics showed full mains (240 V) entering the control board, but only a few volts exiting to the heater. That points to an open heater circuit, a blown thermal fuse, or a switching fault on the control board. Measure voltage at heater leads with the heater disconnected to isolate the issue. [Elektroda, kesy1, post #16641287]

What usually fails first: heater, fuse, or control board?

Experienced repairers report thermal fuses as the most frequent failure, followed by control electronics. If a fuse opened, find why before installing a new heater. “Most often one of the thermal fuses is damaged.” Replace the NTC sensor with the fuse if heat stress is suspected. [Elektroda, nioop, post #16640889]

How do I test the thermal fuses on the heater block?

With power unplugged, access the heater and identify the two inline thermal fuses. Test each fuse for continuity using an ohmmeter. A good fuse reads near 0–2 Ω; an open reading means replacement. You do not need to desolder if you can isolate one lead for testing. Confirm the heater element itself reads roughly 35 Ω when measured past the fuses. [Elektroda, bosman116, post #16652690]

Could a bad control board fry my new heater immediately?

Yes. A shorted power module can energize the heater as soon as you plug in the machine. Test with the old heater first by temporarily bridging around the blown fuse for diagnosis only. Keep wires away from metal parts to avoid shorts. If it heats instantly at idle, repair the board before fitting new parts. [Elektroda, bosman116, post #16652867]

What is an NTC sensor in this coffee machine?

An NTC (Negative Temperature Coefficient) sensor measures heater temperature; its resistance drops as temperature rises. The control board uses this to regulate heating and protect from overheating. If a thermal fuse blew, replace the NTC alongside to restore reliable temperature control. Faulty NTC readings can prevent heat-up or cause safety trips. [Elektroda, nioop, post #16642116]

How can I safely check heater voltage output from the board?

Disconnect heater leads first. Power the machine and command hot water. Measure across the heater output terminals. Expect switched mains when heating is requested. If you see only a few volts, the board isn’t driving the heater, or a sensor/fuse interlock is open. Reconnect power only when probes and leads are stable and insulated. [Elektroda, nioop, post #16642116]

How do I remove the bean container to reach the NTC or heater wiring?

Empty the beans. Unhook the two optical presence sensors from their clips. Release the grinder-area hooks and lift the container straight up. Remove the outer casing around the machine first; “It will be much easier.” This provides top access for sensor and wiring service. [Elektroda, bosman116, post #16680123]

Is there a simple 3-step process to diagnose ‘water heating up’ then reset?

  1. Measure heater element resistance out of circuit; target ~35 Ω.
  2. Check both thermal fuses for continuity; replace any open units.
  3. With heater disconnected, verify the control board outputs switched mains to heater terminals during heat request. Perform steps in order to avoid damaging new parts. [Elektroda, kesy1, post #16652847]

What resistance values did successful repairs observe?

One repair reported about 35 Ω for the heater and around 1.5 Ω across the intact thermal fuse. Those figures indicate a sound element and a good low-resistance fuse. Use them as ballpark checks during troubleshooting. Replace any component that reads open or wildly outside these values. [Elektroda, kesy1, post #16652847]

After replacing the heater, should the machine work immediately?

Yes, if the root cause was a failed heater or fuse. The thread’s resolved case reported full function after installing a new heater. Always confirm no board short exists before final assembly to avoid repeat failures. Run a hot-water cycle and a coffee cycle to verify heat-up stability. [Elektroda, kesy1, post #16681885]

Can I operate the machine with a bypassed thermal fuse for testing?

Only briefly and only for diagnostics with the old heater connected. Keep all bridged conductors insulated and isolated from metal. If the heater energizes at idle, stop and repair the power module. Do not leave a fuse bypassed in normal use; it is a critical safety device. [Elektroda, bosman116, post #16652867]

What if I measure infinity on the heater and only a few volts leaving the board?

An infinite reading indicates an open circuit in the heater path. The few volts at the board output suggest it isn’t driving a valid load due to the open heater or fuse. Replace the blown fuse or element, then recheck for normal mains switching at the output. [Elektroda, kesy1, post #16641287]

What brands or tools are helpful for this repair?

Use a reliable multimeter with continuity and resistance modes, insulated probes, and clip leads. Keep a spare NTC sensor and thermal fuses matched to the heater assembly. Bosch TES50321RW/12 owners follow identical access steps for the bean container and top cover. Label connectors to ease reassembly. [Elektroda, bosman116, post #16680123]
Generated by the language model.
ADVERTISEMENT