diyrebel

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[–] [email protected] 2 points 3 weeks ago* (last edited 3 weeks ago) (1 children)

I appreciate your insights but struggle to reconcile the following with what others say (youtubers and folks in an electronics chat room):

I doubt many people use eeprom to save any kind of error. … It is far more likely that the script is just a state machine and is reaching an error state because of some missing or bad signal that it needs to continue running the script.

I asked EE folks how would a controller board sense a fault? Does the controller take resistance measurements on the components? The answer was “highly unlikely - that would be far more sophisticated and costly than what would be realistic in a domestic washing machine”. They said fault detection is based on logic. E.g. if the tacho sensor does not have increasing feedback despite increasing power to the motor, then the controller can detect from that that there is a fault. Or if the water has been filling for a long time and the pressure sensor is not detecting a pressure increase, the machine would know from that activity that the inlet valve has a problem.

You seem to suggest that the script reruns from a clean state every time and that a “bad signal” would be re-detected each run, which then implies that the machine would repeatedly attempt to fill with water, tumble, drain, etc. But that does not seem to be what I am seeing. The machine will be powered off & unplugged for days, and when powered on it instantly flashes that there is a fault (which is likely only known after attempting to run the various components). This is consistent with what a Youtuber said: the machine (not my particular model but speaking generally) stores the fault code. From there, the machine is trapped in that state until the error code is cleared by pressing a secret sequence of buttons.

Some leaked tech docs for a different model (same make) mentioned that if a fault occurs 8 times, it then becomes stored in memory. This seems consistent with what I observed. I repeatedly attempted to run the machine. Not sure how many times. Motors would run, failure hits, and then it quits. After doing that so many times (which I regret), the behavior changed. Now the machine will not even attempt to run because it is apparently trapped in an error state.

So everything seems to point to the error code being stored in EEPROM (which I believe is embedded in the ATmega32L chip). And not just the error code but apparently a count of failed attempts to run a program.

[–] [email protected] 2 points 3 weeks ago* (last edited 3 weeks ago) (3 children)

I don’t intend to modify the program. I am just looking to reset the state of the software to get it out of the fault state.

Normally that can be done by using the buttons on the PCB to enter a secret combination code to:

  • enter diagnostic mode
  • run various functions/cycles which normally run as part of a program
  • see the error code
  • reset the board

When the software detects a fault (such as a broken pump), it saves the error code. Then if you fix the pump, the software doesn’t know the pump has been fixed. So the board has to be reset to clear the error code.

The button sequence codes are secret and known only to the manufacturer. They are very protectionist. In Europe, law requires them to make the codes available to other 3rd party technicians -- but only in the 1st ten years and they can also charge a fee. Consumers get no access under any circumstances.

My thought was theoretically a pro independent repair service would not want to pay every manufacturer for the secret info for every model they repair -- so perhaps they would attach to the USART serial port and have a way to see errors and reset the board. But if it’s as you say, then the USART is disabled and useless to repairers. Which means I’m stuffed because I cannot buy a replacement card for my machine.

If the serial port is not disabled, you conjecture that it is likely a read-only non-interactive mechanism. That still may be useful. I was able to find the secret button combination that is likely giving me an error code which I can guess the meaning of based on leaked docs for other models, but I’m not satisfied with that. I would be useful if I could get more verbose or supplemental info about the error state.

There is some chatter about GE washing machines (not what I have) include an rj-45 port and that they released some kind of open source thing called the green bean which adapts USB to serial. On the one hand, it suggests that not all manufacturers intend to prevent communication with the PCB. OTOH, this actually seems to not be for service use but for sending notifications to the user.

[–] [email protected] 2 points 3 weeks ago (5 children)

The MCU is an ATmega32L, which seems to be well documented. I was able to fetch a 300+ page document and a 12 page overview of the specs.

[–] [email protected] 2 points 3 weeks ago* (last edited 3 weeks ago)

There is no service manual within my reach. I would have to resort to bribery, torture, breaking and entry, and theft to get one. Thanks for the link but that only seems to cover N.American makes.

This is in fact why I am looking to probe the serial port. To try to poke around since I don’t know the secret steps to reseting the board.

 

cross-posted from: https://lemmy.dbzer0.com/post/38015770

A washing machine is trapped in a fault state even though all the components function (AFAICT). The controller board has two ports:

  • ISP (to attach an ISP programmer to flash new software)
  • USART (4-pin serial port: 0v, TX, RX, 5v)

I’m guessing the ISP port is useless without whatever proprietary software is needed. But what can the USART do for me? Can that be used to obtain the error code and clear it, or reset the board to the factory state? Has anyone done that, without documentation?

 

cross-posted from: https://lemmy.dbzer0.com/post/38015770

A washing machine is trapped in a fault state even though all the components function (AFAICT). The controller board has two ports:

  • ISP (to attach an ISP programmer to flash new software)
  • USART (4-pin serial port: 0v, TX, RX, 5v)

I’m guessing the ISP port is useless without whatever proprietary software is needed. But what can the USART do for me? Can that be used to obtain the error code and clear it, or reset the board to the factory state? Has anyone done that, without documentation?

 

A washing machine is trapped in a fault state even though all the components function (AFAICT). The controller board has two ports:

  • ISP (to attach an ISP programmer to flash new software)
  • USART (4-pin serial port: 0v, TX, RX, 5v)

I’m guessing the ISP port is useless without whatever proprietary software is needed. But what can the USART do for me? Can that be used to obtain the error code and clear it, or reset the board to the factory state? Has anyone done that, without documentation?

[–] [email protected] 1 points 1 month ago (1 children)

I appreciate the guidance. But I think I can rule out insulation breakdown because I just removed the cover to the tacho generator and the ring magnet was broken in two pieces.

 

My washing machine had the same symptoms as this one, which is the same make but different model. It suggests a bad tacho. I need more certainty before buying parts.

The state worsened. Now I just get a non-stop continuous blinking LED with all flashes evenly spaced (thus no error code).

Someone told me the advice on this page is sketchy. IIUC, that page says to hand-spin the motor while the tacho is connected to an ohms meter. I get very little variation. If I give it a spin as fast as I can, it goes from 52 Ω to 52.8 Ω.. or 53 Ω on one occasion. Someone said it’s wrong or bad to put current through an ohms meter. So is that a bad test?

There are different kinds of tachos. Mine uses a coil, which I suppose implies that I an dealing with the rotating magnet variety.

voltage test (I am ill equipped)

Some people apparently read the AC voltage of a tacho while spinning it. My meter only has 2 scales for AC voltage: 500 and 200, which are far too high to detect anything. Should I buy a meter that detects AC mV?

Hz test (I am ill equipped)

My meter does not have frequency. Should I buy a meter with Hz?

scope test ~~(I am ill equipped)~~

Apparently an oscilloscope app can be fed by a smartphone’s mic input. But I do not have an AOS 6+ phone.

(edit) There are a couple FOSS desktop apps:

  • PulseView
  • xoscope (I will not link it because the project is Cloudflare-jailed)

So I might try this. I think the input can simply be wired to the mic input, but it’s better to build a circuit:

earphone test (strange result)

I connected the tip of the 3.5mm phono connector for audio headphones to one tacho lead and the middle segment to the other lead. When I spun the drum by hand, it sounded in the right speaker just like the drum sounds to my naked ears as it spins. That can’t be right. Must be all in my head. Is this test useless?

compass test (unlikely to be useful)

I could theoretically run a compass app and hold the smartphone up next to the tacho as it spins to see if the magnet is still magnetic. But I’m told it’s unlikely that the magnet became demagnetized unless I sent 230 VAC to it -- (and I did not).

hotwire tests on other components

  • 230 VAC → universal motor (spins fine)
  • 230 VAC → drain pump (spins fine)
  • 230 VAC → water inlet valves (opens fine; water flows)

what now?

I don’t understand why a tacho would go bad. So how should I test my tacho? Should I buy a meter that does frequency and low AC voltages?

Ultimately I need to know what the PCB thinks is broken whenever it is told to run a program. Is the PCB doing an ohms test to test the health of the tacho?

[–] [email protected] 1 points 1 month ago* (last edited 1 month ago)

i just see a blank page where an article would go. There is a giant ad at the top and typical garbage down the sides and at the bottom, but no text in the article to read.

(edit) is it just an image? I have images disabled so I wonder if that’s my issue.

[–] [email protected] 1 points 1 month ago* (last edited 1 month ago) (3 children)

Thanks for the feedback! So I guess I should buy a megger. Wow.. not cheap. I think I see these at local 2nd hand street markets. I often thought “what strange multimeter.. so few functions” but I didn’t realize what I was looking at. I will look for something that dials “500V” and has fewer modes than a multimeter, and ideally a “MΩ” printed somewhere although it looks like they won’t all print that on the device. I should probably learn how to test the megger itself so I buy something that works.

I suppose I could try to bring the motor into an appliance repair shop and pay them to test it with a megger.

As far as diagnosis of the whole machine-- suppose it’s true that I have an insulation failure. The control panel LEDs light up correctly when powered on, then when I try to start a program the start button just blinks. Does it seem viable or likely that faulty insulation would cause the controller to behave that way? I get the impression that the blinking LED means the controller detected an unspecified fault of some kind & refused to continue, which tempts me to think that the controller is functioning correctly -- unless it’s a false positive of a failure.

I really want to avoid replacing multiple major parts because I don’t imagine I can return special ordered parts.

(update) At the street market I saw something like this for €100:

https://www.tekcoplus.com/cdn/shop/products/gain-express-gainexpress-Multimeter-SM-852B-set_1024x1024.jpg?v=1553658696

which was apparently a lousy price. I also saw a megger for €160 that looked kind of like this:

https://cdn.globalso.com/hvhipot/GD3128-Series-Insulation-Resistance-Tester2.jpg

I guess that’s what I need. It’s probably a good price for what it is, but not justified for my mission.

[–] [email protected] 1 points 1 month ago* (last edited 1 month ago) (5 children)

Right but I think that safety capacitor (SC) is the last thing I care about. IIUC, I could perhaps even simply bypass the SC because it’s merely improving the power quality/safety. It’s not worth buying an SC unless I can fix whatever is broken. If I could get the machine working, I could then of course consider replacing the SC as a final protective measure -- but I’m not even sure anything is wrong with the SC.

The task at hand is testing every essential component of the washing machine, starting with the motor and tacho. I would like to understand what happened with the SC and motor though. Did I wire the motor wrong which caused the SC to flash and produce bad output for a moment? I don’t want to repeat that. I could power the motor directly without the SC, but if the motor is doing upstream damage then I guess I wouldn’t want my breaker box on the chopping block.

 

cross-posted from: https://lemmy.dbzer0.com/post/36272192

My washing machine is dying in stages. It started with the same symptoms as this thread. Specifically, after filling the tub for a wash cycle, it would go straight into a high-speed spin (full of water!) for a second or two (instead of the expected slow tumble), then quit. The speculation is that the tachometer is failing.

Then the machine got worse. I now cannot even start any program. No matter what program I select, I press start and after a few second pause the start button LED just blinks. It’s a generic blunt signal of a fault. The blinks are evenly spaced non-stop, so there is no error code of any kind.

To test the universal commutative motor, I followed the linked video and took resistance measurements. All seems okay in that regard (but this is based on vague resistance ranges that are not specific to my machine). Test results:

tachometer

Expectation: any reading that is not infinite/disconnected is fine.

  • (video): 70 Ω
  • (my motor): 52 Ω

carbon brushes:

Expectation: should be in the range 1—7 Ω

  • (video): 5 Ω
  • (my motor): 3.45 Ω

field windings:

Expectation: all combinations should be 1-7 Ω

  • (video): 3.5 Ω
  • (my motor): pin1-2: 1.35Ω, pin1-3: 1.35Ω, pin2-3: 1.9Ω

I do not have whatever model is in that video, but my readings are in the range suggested by the video presenter, fwiw. I believe my testing is incomplete because I was expecting the tachometer to be bad based on the behavior.

Motor spin test (hotwiring)

My next move was to try to make the motor spin. There is no service manual or wiring diagram for my Beko. So I inspected the motor and derived these pins (quotes are labels on the PCB):

1 (field) brown socket → brown+white “stator M” 2 (field) black socket → purple+white “stator 1” 3 (field) blue socket → red+white “commu” (commutator) 4 (brush) white socket → purple+yellow “rotor 2” 5 (brush) red socket → green+red “rotor 1” 6 (tacho) yellow socket → green “tacho” 7 (tacho) yellow socket → green “tacho” 8 (ground) green+yellow socket → green+yellow

Someone suggested this wiring:

L → pin 1
N → pin 5
jumper connecting pins 3 & 4

I did not connect direct to the wall because I wanted to use the mechanical power button of the machine to turn on and off the motor (so I could quickly cut power if needed). So power took this path:

wall (220 VAC) → safety capacitor → mechanical button → motor (wiring redirected to motor instead of control panel)

When I switched it on, the motor spun for 1 or 2 seconds and I saw a white flash (I think) and the motor quit. I turned it off. Then tried to switch it on again. No response.

220 VAC quit coming out of the safety capacitor. Instead the voltage jumped around between 10 VAC and 20 VAC. So I thought I fried the capacitor or resisters therein. I checked the motor to see if any of the pins connected to ground (answer: no, so the motor was not harmed). Then I disconnected the safety capacitor and connected it just to mains and ground. 220 VAC was output (WTF.. why does it magically work again?)

I think I’m back to the state it was in before I tried to power the motor. But I want to understand why the safety capacitor apparently flashed white and temporarily died with only 10—20vac output. I need to get to the bottom of this because I still need to test the motor for more than 1 second in a way that doesn’t cause more white flashes. Is it a bad idea to have the safety capacitor in the circuit?

 

My washing machine is dying in stages. It started with the same symptoms as this thread. Specifically, after filling the tub for a wash cycle, it would go straight into a high-speed spin (full of water!) for a second or two (instead of the expected slow tumble), then quit. The speculation is that the tachometer is failing.

Then the machine got worse. I now cannot even start any program. No matter what program I select, I press start and after a few second pause the start button LED just blinks. It’s a generic blunt signal of a fault. The blinks are evenly spaced non-stop, so there is no error code of any kind.

To test the universal commutative motor, I followed the linked video and took resistance measurements. All seems okay in that regard (but this is based on vague resistance ranges that are not specific to my machine). Test results:

tachometer

Expectation: any reading that is not infinite/disconnected is fine.

  • (video): 70 Ω
  • (my motor): 52 Ω

carbon brushes:

Expectation: should be in the range 1—7 Ω

  • (video): 5 Ω
  • (my motor): 3.45 Ω

field windings:

Expectation: all combinations should be 1-7 Ω

  • (video): 3.5 Ω
  • (my motor): pin1-2: 1.35Ω, pin1-3: 1.35Ω, pin2-3: 1.9Ω

I do not have whatever model is in that video, but my readings are in the range suggested by the video presenter, fwiw. I believe my testing is incomplete because I was expecting the tachometer to be bad based on the behavior.

Motor spin test (hotwiring)

My next move was to try to make the motor spin. There is no service manual or wiring diagram for my Beko. So I inspected the motor and derived these pins (quotes are labels on the PCB):

1 (field) brown socket → brown+white “stator M” 2 (field) black socket → purple+white “stator 1” 3 (field) blue socket → red+white “commu” (commutator) 4 (brush) white socket → purple+yellow “rotor 2” 5 (brush) red socket → green+red “rotor 1” 6 (tacho) yellow socket → green “tacho” 7 (tacho) yellow socket → green “tacho” 8 (ground) green+yellow socket → green+yellow

Someone suggested this wiring:

L → pin 1
N → pin 5
jumper connecting pins 3 & 4

I did not connect direct to the wall because I wanted to use the mechanical power button of the machine to turn on and off the motor (so I could quickly cut power if needed). So power took this path:

wall (220 VAC) → safety capacitor → mechanical button → motor (wiring redirected to motor instead of control panel)

When I switched it on, the motor spun for 1 or 2 seconds and I saw a white flash (I think) and the motor quit. I turned it off. Then tried to switch it on again. No response.

220 VAC quit coming out of the safety capacitor. Instead the voltage jumped around between 10 VAC and 20 VAC. So I thought I fried the capacitor or resisters therein. I checked the motor to see if any of the pins connected to ground (answer: no, so the motor was not harmed). Then I disconnected the safety capacitor and connected it just to mains and ground. 220 VAC was output (WTF.. why does it magically work again?)

I think I’m back to the state it was in before I tried to power the motor. But I want to understand why the safety capacitor apparently flashed white and temporarily died with only 10—20vac output. I need to get to the bottom of this because I still need to test the motor for more than 1 second in a way that doesn’t cause more white flashes. Is it a bad idea to have the safety capacitor in the circuit?

[–] [email protected] 1 points 1 month ago

I appreciate the explanation. Interesting to hear the term “was motor”, which I always thought of as a valve but I guess the fact that the wax moves a valve it’s sensible to call it a motor. IIUC, it’s similar to thermostatic shower mixers, but with a floor temp of 5°C.

 

Wall radiators have a valve that has this progression of settings: “❄ 1 2 3 4 5”. Naturally as you turn it a pin changes position which opens a mechanical valve a precise amount.

The question is what happens at “”? I always thought of that as zero, completely closed. But my central boiler seems to target 5°C/40°F even when off to protect pipes from freezing. So what happens if all the radiator valves are off/closed (❄) and the boiler is triggered to prevent freezing? Does each valve also have a thermostat to open at freezing?

I thought for years the snowflake just meant cold (closed). But I wonder if it actually means frost protection, where it does something smarter. There are times when it’s in that ❄ position and yet the radiator still heats up. I thought the valve was broken, but then other radiators occasionally did the same. Is that normal?

[–] [email protected] 1 points 4 months ago* (last edited 4 months ago) (1 children)

It did not seem to struggle to spin. It seemed to have the muscle to spin with a load and water, but crapped out after ~2 seconds every time. ~~Then after trying a few programs it died harder, so nothing happens and it just blinks. I can’t even start a program now. I wonder if the motor driver board would break progressively like that.~~ (edit: I forgot to turn the water back on after hooking back up, so the condition did not deteriorate.. it’s back where it was [starts to spin then quits]).

Thanks for the tip. I try to focus on that component. I wonder if I can send raw power to a couple terminals to test the motor.

[–] [email protected] 2 points 4 months ago* (last edited 4 months ago)

I appreciate the feedback.

The rapid spin that happens in the wash cycle is with the tub full of water. It does not drain it at that time, which is bizarre. So it’s not trying to dump water. It’s a cheap Beko so I don’t suppose it would necessarily be as smart as other machines. When I forcibly cancel the program by holding the start button for 3 seconds, then it drains as part of the termination sequence. In the spin-only program I can hear the pump for a second between spin attempts, but it’s a dry tub in that test.

No matter what program I am running, it makes 4 or 5 attempts to high-speed spin the quits with a blinking start button light. But every task seems fine. Fills with water without issue, drains without issue, spin looks good until it gives up. It’s just opting to do the wrong task. I guess a sensor of some kind could be the culprit. Youtube is a piece of shit lately with Google’s protectionism but I might try to see if I can reach videos on this machine.

Beko is a popular cheap brand. Not sure about part availability yet. It’s a Beko wmd 26125 T.

Found repairportal.beko.com but it’s broken for me. Though archive.org’s 2022 copy of that site suggests they have spare parts.

 

The wash cycle is broken. Just after the tub fills, it does a high-speed 2 second spin, as fast as it can get in 2 sec before pausing. Then it pauses for at least a minute. Then it tries again, repeatedly. It’s really strange. Why would it try to do a high-speed spin with a tub full of water? Normally in the wash cycle it just spins very slowly in one direction, then changes direction periodically.

Whatever it’s doing, it gives up and the start button just blinks, which is apparently a blunt non-specific way to say there is a problem. I tried reducing the load to just a couple t-shirts for diagnosis and it still does this even with a nearly empty drum.

The manual does not list this behavior in the troubleshooting section. And I found no chatter about this behavior in web searches¹. This problem sounds similar but in their case it happens in the spin cycle. In my case it strangely happens in the wash cycle.

  • Hand wash program (empty drum): it still tries a high-speed spin in the wash cycle. A hand-wash program should probably not even consider doing that.
  • Spin program (empty drum): indeed there is a whole program just for spinning and draining. When I run it empty, it high-speed spins for 2 seconds and quits just like with the other programs. It looks like a perfect spin and sounds like it always has. It pauses for a minute then tries again, repeatedly.

~~Update: things just got worse. Now it will not do anything. Power on → start spin program (or any other program) and the start button just flashes. It’s detecting a fault of some kind without doing anything.~~ (edit: I forgot to turn the water back on after hooking back up, so the condition did not deteriorate… it’s back where it was [starts to spin then quits]).

I removed the back panel. Belt looks fine as far as I can tell. Removed the top cover. Springs are fine. Nothing looks unexpected. I pulled all the connectors off and re-sat them. Noticed a sticker dated 2009. Plugged it back in and same problem. Blinks like there is a fault and does nothing. The author of this post took various measurements. I have a multimeter but no idea what to check. I’m not even sure what one of the components is.

Apparently what I need most is the service manual at this point. Right to repair laws have been negotiated for the past 10 years and still nothing is enacted. It’s killing me. There should be an r2r infra in place by now so we can get manuals.

¹(update 3 months later: found another thread on the same problem here. Apparently it’s a broken tachometer.)

[–] [email protected] 1 points 5 months ago* (last edited 5 months ago)

IRC for Android ← antithetical to privacy
IRC for linux PCs that can be hardened and routed over Tor ← privacy respecting

This thread does not belong here.

 

When an arrogant presumptuous dick dumps hot-headed uncivil drivel into a relatively apolitical thread about plumbing technology and reduces the quality of the discussion to a Trump vs. $someone style shitshow of threadcrap, the tools given to the moderator are:

  • remove the comment (chainsaw)
  • ban the user from the community (sledge hammer)

Where are the refined sophisticated tools?

When it comes to nannying children, we don’t give teachers a baseball bat. It’s the wrong tool. We are forced into a dilemma: either let the garbage float, or censor. This encourages moderators to be tyrants and too many choose that route. Moderators often censor civil ideas purely because they want to control the narrative (not the quality).

I want to do quality control, not narrative control. I oppose the tyranny of censorship in all but the most vile cases of bullying or spam. The modlog does not give enough transparency. If I wholly remove that asshole’s comment, then I become an asshole too.

He is on-topic. Just poor quality drivel that contributes nothing of value. Normally voting should solve this. X number of down votes causes the comment to be folded out of view, but not censored. It would rightfully keep the comment accessible to people who want to pick through the garbage and expand the low quality posts.

Why voting fails:

  • tiny community means there can never be enough down votes to fold a comment.
  • votes have no meaning. Bob votes emotionally and down votes every idea he dislikes, while Alice down votes off-topic or uncivil comments, regardless of agreement.

Solutions:

I’m not trying to strongly prescribe a fix in particular, but have some ideas to brainstorm:

  • Mods get the option to simply fold a shitty comment when the msg is still on-topic and slightly better quality than spam. This should come with a one-line field (perhaps mandatory) where the mod must rationalise the action (e.g. “folded for uncivil rant with no useful contribution to the technical information sought”).
  • A warning counter. Mods can send a warning to a user in connection with a comment. This is already possible but requires moderators to have an unhuman memory. A warning should not just be like any DM.. it should be tracked and counted. Mods should see a counter next to participants indicating how many warnings they have received and a page to view them all, so as to aid in decisions on whether to ban a user from a community.
  • Moderator votes should be heavier than user votes. Perhaps an ability to choose how many votes they want to cast on a particular comment to have an effect like folding. Of course this should be transparent so it’s clear that X number of votes were cast by a mod. Rationale:
    • mods have better awareness of the purpose and rules of the community
    • mods are stakeholders with more investment into the success of a community than users
  • Moderators could control the weight of other user’s votes. When 6 people upvote an uncivil post and only 2 people down vote it, it renders voting as a tool impotent and in fact harm inducing. Lousy/malicious voters have no consequences for harmful voting and thus no incentive to use voting as an effective tool for good. A curator should be able to adjust voting weight accordingly. E.g. take an action on a particular poll that results in a weight adjustment (positive or negative) on the users who voted a particular direction. The effect would be to cause voters to prioritize civil quality above whether they simply like/dislike an idea, so that votes actually take on a universal meaning. Which of course then makes voting an effective tool for folding poor quality content (as it was originally intended).
  • (edit) Ability for a moderator to remove a voting option. If a comment is uncivil, allowing upvotes is only detrimental. So a moderator should be able to narrow the ballot to either down vote or neutral. And perhaps the contrary as well (like some beehaw is instance-wide). And perhaps the option to neutralise voting on a specific comment.
 

cross-posted from: https://lemmy.dbzer0.com/post/26703241

This diagram is from the service manual of a combi boiler. It’s a flow sensor which detects whether hot water is running, which is then used to trigger on-demand heat and switch a diverter to take radiators out of the loop.

In English, the diagram shows:

  • X ⅔ red wire (+5V)
  • X 2/2 black wire (ground)
  • X 2/6 green wire (signal)

I need to know what those fractions mean. I took the voltage measurements in this video:

I cannot necessarily trust the model in that video to have the same specs as mine. My voltmeter detected 4.68 V on the red input wire showing that the sensor is well fed. The green “signal” wire is supposed to be 0 V at rest and 2 V with water running (or I think the reverse of that is used in some models). In my case the green wire is ~1.33 V at rest and ~0.66 V when water is running. I need to know if these readings are normal as I troubleshoot this problem.

update


@[email protected] and a couple others gave the answer I was after. Then @[email protected] helped solve the underlying problem. The theory that the sensor was fine but the board was not drove me to test the sensor in isolation. The sensor gave correct output in isolation. Then I connected it back to the motherboard to retest and reconfirm that it’s still broken. But it actually worked. The hot water suddenly and mysteriously works now. I guess the act of draining the water and unplugging the connector then reconnecting and repressurizing caused it to work. It may be temporary, since in the past it was hit or miss whether it would work.

 

cross-posted from: https://lemmy.dbzer0.com/post/26703241

This diagram is from the service manual of a combi boiler. It’s a flow sensor which detects whether hot water is running, which is then used to trigger on-demand heat and switch a diverter to take radiators out of the loop.

In English, the diagram shows:

  • X ⅔ red wire (+5V)
  • X 2/2 black wire (ground)
  • X 2/6 green wire (signal)

I need to know what those fractions mean. I took the voltage measurements in this video:

I cannot necessarily trust the model in that video to have the same specs as mine. My voltmeter detected 4.68 V on the red input wire showing that the sensor is well fed. The green “signal” wire is supposed to be 0 V at rest and 2 V with water running (or I think the reverse of that is used in some models). In my case the green wire is ~1.33 V at rest and ~0.66 V when water is running. I need to know if these readings are normal as I troubleshoot this problem.

update


@[email protected] gave the right answer. Someone in another cross-post helped solve the underlying problem.

 

This diagram is from the service manual of a combi boiler. It’s a flow sensor which detects whether hot water is running, which is then used to trigger on-demand heat and switch a diverter to take radiators out of the loop.

In English, the diagram shows:

  • X ⅔ red wire (+5V)
  • X 2/2 black wire (ground)
  • X 2/6 green wire (signal)

I need to know what those fractions mean. I took the voltage measurements in this video:

I cannot necessarily trust the model in that video to have the same specs as mine. My voltmeter detected 4.68 V on the red input wire showing that the sensor is well fed. The green “signal” wire is supposed to be 0 V at rest and 2 V with water running (or I think the reverse of that is used in some models). In my case the green wire is ~1.33 V at rest and ~0.66 V when water is running. I need to know if these readings are normal as I troubleshoot this problem.

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