we have recently had an Ecodan ASHP installed, worked great for a few days but then noticed it kept giving L9 error every night from 10–11pm. The only think to happen at them times is that the UFH goes off at 10pm but I’m guessing by the time the actuators close etc it’s probably why it happens at random times.
I have changed the UFH to go off at 11:00pm and now L9 happens 11:30ish. Once reset the ASHP is reset the system works lovely, but what’s weird is if I turn the stats down during the day everything works fine. Only seems to happen on a night!!
Our installer said Mitsubishi have said it’s a dodgy 2 port valve, which is maybe but he can’t get back for a little while as he’s away at the moment. But if I can get some help it means I pay and get someone else in to fix it but don’t want to throw money at the problem without knowing.
thank you 🙏🏻
Best answer by Peter E
I’ve recently started asking ChatGPT for the range of ideas of what this could be. It came back with this answer:
This is a copy of a conversation between ChatGPT & Anonymous.
You said:
A Mitsubishi Ecodan ASHP is giving an L9 error every night at the same time. It has been suggested that the two port valve is faulty. Id that likely to be the cause?
ChatGPT said:
The L9 error on a Mitsubishi Ecodan Air Source Heat Pump (ASHP) typically indicates a low water flow or flow-related issue. This could be due to several causes, and a faulty two-port valve is one possibility, but let's explore it in more detail.
Possible Causes for L9 Error:
Faulty Two-Port Valve:
If the valve is not opening or closing correctly, it could restrict water flow, triggering the L9 error.
Since the error occurs at the same time every night, it’s possible the valve is programmed or reacting to a timed event (like a scheduled heating cycle).
Flow Sensor Issues:
The flow sensor could be malfunctioning, giving a false reading of low flow.
Check for debris or dirt on the sensor.
Pump Issues:
The circulation pump might be failing or running intermittently, especially if the error is time-specific.
Check if the pump is running when the error occurs.
Air Locks in the System:
Air trapped in the system can reduce water flow. Bleeding the radiators and system could resolve this.
Blocked Filters or Strainers:
Dirty or clogged filters can restrict flow, especially if debris builds up during the day and triggers the error at night.
System Pressure:
Low system pressure could contribute to flow issues. Ensure the pressure is within the recommended range.
External Timers or Controls:
If there's an external control system or timer, it could be interacting with the ASHP in a way that restricts flow at night.
Troubleshooting Steps:
Check the Two-Port Valve:
Manually operate the valve to see if it moves freely.
Listen for any unusual noises or check if the actuator is getting power when it should open.
Inspect Flow Rates:
Check the flow sensor readings and see if they drop before the L9 error appears.
Monitor the pump to ensure it’s running consistently.
Look for Patterns:
Since the error is time-specific, consider if other equipment (like thermostats or timed controls) is triggering the issue.
Consult Error Logs:
If the Ecodan has a diagnostic mode, review the error logs to see if there’s more detailed information.
Is the Two-Port Valve Likely the Cause?
Given that the error happens at the same time every night, it could point to the valve being controlled incorrectly or failing under certain conditions. However, it’s equally possible that a timer-related issue, pump failure, or flow sensor problem could be to blame.
It’s worth testing the valve first as it's a common culprit, but keep other flow-related components in mind if the problem persists.
Let me know how it goes or if you need more specific steps!
Messages beyond this point are only visible to you
Welcome to the community! I’ll tag a few of our members from other Ecodan threads who might be able to offer some advice. We’re not experts in Ecodan by any means but we’ll see what we can offer 😃
I'm mostly offline this morning but I would suggest looking to see if that part is known to be faulty on the Ecodan by looking for comments on an Ecodan forum. I'll be back later ...
I’ve recently started asking ChatGPT for the range of ideas of what this could be. It came back with this answer:
This is a copy of a conversation between ChatGPT & Anonymous.
You said:
A Mitsubishi Ecodan ASHP is giving an L9 error every night at the same time. It has been suggested that the two port valve is faulty. Id that likely to be the cause?
ChatGPT said:
The L9 error on a Mitsubishi Ecodan Air Source Heat Pump (ASHP) typically indicates a low water flow or flow-related issue. This could be due to several causes, and a faulty two-port valve is one possibility, but let's explore it in more detail.
Possible Causes for L9 Error:
Faulty Two-Port Valve:
If the valve is not opening or closing correctly, it could restrict water flow, triggering the L9 error.
Since the error occurs at the same time every night, it’s possible the valve is programmed or reacting to a timed event (like a scheduled heating cycle).
Flow Sensor Issues:
The flow sensor could be malfunctioning, giving a false reading of low flow.
Check for debris or dirt on the sensor.
Pump Issues:
The circulation pump might be failing or running intermittently, especially if the error is time-specific.
Check if the pump is running when the error occurs.
Air Locks in the System:
Air trapped in the system can reduce water flow. Bleeding the radiators and system could resolve this.
Blocked Filters or Strainers:
Dirty or clogged filters can restrict flow, especially if debris builds up during the day and triggers the error at night.
System Pressure:
Low system pressure could contribute to flow issues. Ensure the pressure is within the recommended range.
External Timers or Controls:
If there's an external control system or timer, it could be interacting with the ASHP in a way that restricts flow at night.
Troubleshooting Steps:
Check the Two-Port Valve:
Manually operate the valve to see if it moves freely.
Listen for any unusual noises or check if the actuator is getting power when it should open.
Inspect Flow Rates:
Check the flow sensor readings and see if they drop before the L9 error appears.
Monitor the pump to ensure it’s running consistently.
Look for Patterns:
Since the error is time-specific, consider if other equipment (like thermostats or timed controls) is triggering the issue.
Consult Error Logs:
If the Ecodan has a diagnostic mode, review the error logs to see if there’s more detailed information.
Is the Two-Port Valve Likely the Cause?
Given that the error happens at the same time every night, it could point to the valve being controlled incorrectly or failing under certain conditions. However, it’s equally possible that a timer-related issue, pump failure, or flow sensor problem could be to blame.
It’s worth testing the valve first as it's a common culprit, but keep other flow-related components in mind if the problem persists.
Let me know how it goes or if you need more specific steps!
Messages beyond this point are only visible to you
I’ve taken to exploring how useful ChatGPT answers are and in general the seem to be lesss precise/detailed than you might want but it does seem to provide a variety of possible causes well beyond I would have thought of myself. I can only suggest you read through and try the practical steps that you can take yourself as it may be able to narrow the fault a bit more.
If it’s a normal plumbing job then you could call a plumber instead of a heat pump engineer. I do a similar thing for my EV. I get my local garage to fix the mechanical issues which don’t involve any of the EV parts.
Really appreciate all the help, and happy to say it’s all sorted. Turns out the auto bypass valve wasn’t passing, so a new one has been installed and should be good 🤞🏻
Error was only happening during the freeze stat cycle so helped narrow the fault down.
Amazing work @Darkforce thank you so much for coming back and letting us know the outcome. This’ll be really helpful as we have a good sized Ecodan community that come seeking advice 😍
Thank you again to @Peter E and @BPLightlog for also stopping by! I loved the creative thinking asking AI for it’s take on it Peter!
To be honest you are not going to beat an experienced engineer but using the output generated by AI may trigger a thought as to what the problem is and may result in not having to call out an engineer in the first place. The alternative is sifting pages of mostly irrelevant search results. AI seems to cut that out and it also asks you if you want to refine the results by supplying information to specific questions. A simple Google search doesn't do that. What you mostly get is ranting between plumbers.
Not without prompting. That seems to suggest that the result might have been skewed by providing a guess. It also suggests that it hadn't seen the correct answer but that might not have got onto the web yet for it to see at that time. I can't remember if this version gathers real time information or just historic data.
I further asked if the bypass valve might cause the problem and it said that was a possibility during a defrost cycle when it needed to open and would cause the error code seen so it does know about that . I might have skewed the question. It a habit I've got into with Google searches in that if, along with the question, you put as much as the answer as you know then it tends to return more targeted results.
I think it comes down to knowing how best to use the tool and this old dog is going to have to learn new tricks.
Peter
Just checked and ChatGPT uses live information from Bing
Thank you for this it’s interesting to know just how effective a tool it can be if used in the right environment. My thinking is i’ll use AI to try an uncover things that I haven’t thought about but I still don’t have trust in it providing me with a “final answer”. I think that should always be controlled by the person seeking the answers in the first place.
Now if I can just get AI to make me a good coffee..
I'm just finding that it zooms straight to the heart of the issue and then gives you a wide view of the whole thing in one place. From that point you can immediately see where to refine your search just by adding a correction or an addition to what you first said. It's essentially an ongoing conversation rather than having to start again with a modified search. The relationship is different from being presented with a box full of different and quite often irrelevant answers (Google search) to having someone in the room with you who is an expert on that subject. At first I found it a bit unnerving how close it could get to the bullseye with one answer.
But what sets it apart is that it wants to be interactive. After giving you half a page of detailed answer if often says, If you want me to refine the results I can do that if you are happy to answer some questions.
And finally, having finished the conversation you can say Thank you and it will respond positively to that as well.
You can access ChatGPT through a browser but I now use the app.
Peter
I'm still working on how it can make a coffee for me but I'm sure @Blastoise186 has already got AiCoffeeMaker 3.2 so just ask him for the details.
I can do one better - Multidimensional I already have a Multidimensional AiCoffeeMaker 3000 :P
But yeah, just like I was talking about elsewhere recently, AI is useful in some cases to kickstart my research, however it ultimately falls apart because it has a habit of going off track or giving unhelpful answers...
That's a good point. Threads wander, they always do, but who is the arbiter of that? I would guess that would be a moderator to decide perhaps based on whether the topic that had been wandered onto merits a thread of its own or has no merit at all. Perhaps the use of AI in the context of providing answers here does warrant a new thread on the PZH forum but it seems to me that it has already come to a conclusion here. But in the course of the wander another mention of AI has been made on the open forum and how it could be used to seek answers before coming on here. A self-help route if you like that can be used to resolve other issues as well as I have found.
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