Judith Posted June 8, 2023 Share Posted June 8, 2023 So this is our question about ASHP. We have a Joule Aero for DHW. (Space heating is, in theory, MVHR with an old Genvex 400 with heat pump, plus duct heaters, but that's a whole nother story). And we have a PV roof and a Marlec iBoost to divert excess energy to the immersion in the Joule. First problem is that this has never worked properly. As soon as the sun comes out or we manually select Boost, the heat pump in the Joule displays an error message and stops functioning. After advice from Joule, a second immersion was fitted, but that hasn't resolved it. Second, urgent, problem is that when we came back from a recent break the iBoost was displaying Sender battery LOW. T(he Sender is a small item near the consumer unit that monitors the electricity consumption in order to trigger the diversion to the heat pump.) So we replaced the ordinary AA batteries with brand new ones - in fact we did it twice to be certain - and it continues to display Sender battery LOW. We can still get hot water by using the manual boost, and can do it when the sun comes out, but there is no automatic diversion. I emailed Marlec and they replied "it would be advisable to have your immersion/thermostat checked out by an electrician as it could be a fault with that." Any ideas of what to do? Joule have so far not been helpful when contacted and the electrical company that installed it complain they can't get any manuals or advice from them. Link to comment Share on other sites More sharing options...
JamesPa Posted June 8, 2023 Share Posted June 8, 2023 (edited) Why do you think this has anything to do with joule, it sounds like a problem with the diverter, not the cylinder or immersion. Unless I'm missing something. Edited June 8, 2023 by JamesPa Link to comment Share on other sites More sharing options...
elite Posted June 8, 2023 Share Posted June 8, 2023 I agree sounds like an issue with the diverter. Though I am curious about what error the diverter is managing to throw on the Joule Maybe diverter and sender need rebooting if they have lost connection? Link to comment Share on other sites More sharing options...
ProDave Posted June 8, 2023 Share Posted June 8, 2023 Can you post some pictures of how the immersion heater on the Joule connects to the diverter? Does the immersion heater also connect to any controls on the Joule? They can't both control it without a very thorough understanding of what connects to what. Link to comment Share on other sites More sharing options...
Judith Posted June 8, 2023 Author Share Posted June 8, 2023 3 hours ago, JamesPa said: Why do you think this has anything to do with joule, it sounds like a problem with the diverter, not the cylinder or immersion. Unless I'm missing something. It was Marlec who said it was to do with the immersion. That's the only reason. Link to comment Share on other sites More sharing options...
Judith Posted June 8, 2023 Author Share Posted June 8, 2023 2 hours ago, elite said: I agree sounds like an issue with the diverter. Though I am curious about what error the diverter is managing to throw on the Joule Maybe diverter and sender need rebooting if they have lost connection? Thank you. It is Marlec, the manufacturer of the diverter, that said it was probably a problem with the thermostat settings on the immersion. I didn't tell them it was a heat pump rather than a simple immersion heater. In fact we have only been using one of the two immersion heaters in the Joule since the installer's engineer gave up on it a couple of years ago. They don't see to have lost connection. That would lead to a different error message. If they have lost connection there are instructions as to how to pair them again, but it seems to be quite difficult. Link to comment Share on other sites More sharing options...
Judith Posted June 8, 2023 Author Share Posted June 8, 2023 2 hours ago, ProDave said: Can you post some pictures of how the immersion heater on the Joule connects to the diverter? Does the immersion heater also connect to any controls on the Joule? They can't both control it without a very thorough understanding of what connects to what. I'm not sure that there is anything that I could take a photo of that would help. The Joule has an immersion heater in it when sold. A second one was fitted inside the unit by a technician who was sent by Joule. He said that would resolve the errors we were getting but it didn't. We have a user's manual about the control system but it is beyond me although I have done some programming in the past, and also beyond all the staff in the supplier (qualified sparks/heat pump technician/electrical-electronic engineer), and Joule have nothing else they can send. I suspect they don't know a lot themselves, and only import them. As I understand it, the extra immersion is controlled by the diverter and the original one comes on periodically to raise the temperature to 60 to prevent legionella, although it probably doesn't while the error message shows. Joule tell us we must have it serviced by them every year or we are non-compliant with the terms of the grant we received on installation; they say they have no responsibility as we haven't completed the servicing booklet which they never gave us in the first place. I suspect we will have to get an independent heat pump engineer round, but how to choose someone who knows what they are doing? Link to comment Share on other sites More sharing options...
ProDave Posted June 8, 2023 Share Posted June 8, 2023 A solar PV diverter normally connects to an immersion heater in a hot water tank, and that heater connects to nothing else whatsoever. So I am struggling to understand why or how, when your solar diverter sends power to the immersion heater how the Joule system even knows that is happening let alone throws some kind of error. That is why I think the immersion must be connected electrically to the Joule system as well. What you need is a competent electrician to confirm the immersion heater your diverter connects to is is ONLY connected to the diveter. Link to comment Share on other sites More sharing options...
ReedRichards Posted June 8, 2023 Share Posted June 8, 2023 In my system I have a diverter (a WiFi-controlled switch) connected to my immersion heater and my heat pump connected in parallel to the immersion heater. Although this configuration seems to scare some people, it has never caused any problems. My heat pump has independent control of this immersion heater but would only use this control for an anti-Legionnaires cycle (which I don't bother with in summer because direct heating by the immersion heater is sufficient). Potentially my heat pump (LG Therma V) could sense when my immersion heater is being powered directly and if it knew the immersion heater was on without a request from the heat pump controller it might well show an error message - but that doesn't happen in my case. Link to comment Share on other sites More sharing options...
Judith Posted June 8, 2023 Author Share Posted June 8, 2023 2 hours ago, ProDave said: A solar PV diverter normally connects to an immersion heater in a hot water tank, and that heater connects to nothing else whatsoever. So I am struggling to understand why or how, when your solar diverter sends power to the immersion heater how the Joule system even knows that is happening let alone throws some kind of error. That is why I think the immersion must be connected electrically to the Joule system as well. What you need is a competent electrician to confirm the immersion heater your diverter connects to is is ONLY connected to the diveter. Sorry I didn't explain correctly. The Joule with its tank is our only source for DHW. A Joule air-to-water heat pump always has an immersion heater in it as a back-up, and the idea was to connect the diverter to that. The heat pump is programmed to come on in the evenings, so we should get hot water in the morning heated by heat pump. Then on sunny days we should be able to use the PV-generated electricity to run the immersion. We were replacing a Vanvex air-to-water heat pump, so didn't want to go back to just an immersion, and we were replacing the PV roof. I hadn't heard of diverters until the electrical company who were doing the PVs suggested it. They brought in a heat pump company, who were assured by Joule there was no reason why it would not work. But it didn't and nobody could work out why. Eventually Joule sent a technician, who put a second immersion inside the Joule (it is designed to be able to incorporate it, or it could take input from solar hot water panels). We've had it all in for 4 years, and although it has been annoying that the heat pump part of the Joule constantly goes to error message, we are saving a lot of money heating all our water by solar. Link to comment Share on other sites More sharing options...
sharpener Posted June 8, 2023 Share Posted June 8, 2023 (edited) 1 hour ago, Judith said: Eventually Joule sent a technician, who put a second immersion inside the Joule (it is designed to be able to incorporate it, or it could take input from solar hot water panels). So it is probable that - whatever was done originally - the Joule technician put the second immersion in so that it could/would be electrically separate from the original one. If that is so it sounds like you have two separate faults, one with the Joule setup (maybe it still thinks there is a separate supply to #1 immersion) and the one with the Marlec diverter. If the wireless link has failed then it might manifest itself as an (incorrect) battery low message. Or the batteries genuinely failed and it lost its pairing as a result. (Honeywell wireless TRVs do something similar.) In either case re-pairing it might resolve it if you can make sense of the instructions. I would expect you would put the master unit (the diverter itself) into a "pairing" mode and then press a button on the Sender or activate it in some other way. The instructions here would seem to confirm this. How far is the sender from the diverter and is there much in the way? Was it 100% reliable before? Sorry I have no suggestions about the Joule problem but getting someone to verify that the #2 immersion is not connected electrically might be helpful. What does the error message say? Has it always been the same? Did the Joule work properly before any attempt was first made to connect the Marlec diverter to it? Edited June 8, 2023 by sharpener Link to comment Share on other sites More sharing options...
Judith Posted June 9, 2023 Author Share Posted June 9, 2023 11 hours ago, sharpener said: So it is probable that - whatever was done originally - the Joule technician put the second immersion in so that it could/would be electrically separate from the original one. If that is so it sounds like you have two separate faults, one with the Joule setup (maybe it still thinks there is a separate supply to #1 immersion) and the one with the Marlec diverter. If the wireless link has failed then it might manifest itself as an (incorrect) battery low message. Or the batteries genuinely failed and it lost its pairing as a result. (Honeywell wireless TRVs do something similar.) In either case re-pairing it might resolve it if you can make sense of the instructions. I would expect you would put the master unit (the diverter itself) into a "pairing" mode and then press a button on the Sender or activate it in some other way. The instructions here would seem to confirm this. How far is the sender from the diverter and is there much in the way? Was it 100% reliable before? Sorry I have no suggestions about the Joule problem but getting someone to verify that the #2 immersion is not connected electrically might be helpful. What does the error message say? Has it always been the same? Did the Joule work properly before any attempt was first made to connect the Marlec diverter to it? Thank you for all this. I will try to re-pair the sender and diverter, as that could indeed be necessary, despite what Marlec said. The sender and diverter are about eight meters from each other and there are only partition walls and furniture between them. They haven't had any problem communicating before. There IS a separate supply to the first immersion. That one is still in use, coming on periodically to bring the temperature to 60 to prevent legionella. The unit is supposed to be designed to allow for a second heat source, e.g. solar hot water, (our old Vanvex was too), and that is how the second immersion was installed. One hypothesis related to the fault is that the heat pump cuts out when the tank is heated beyond its target temperature, outside the periodic raising to 60. The engineer from our electricians has attempted to solve this by altering the target temperatures of the heat pump and the second immersion. And for a while in the winter that worked, i.e. it went for a week or so without going to error message. Right now, I can reset it and it starts to run again, but that only lasts an hour or so. I am becoming convinced that there is nobody in the UK who understands how to get the Joule Aero unit to work with a diverter. Although when we were sold it everyone was "sure, can't see any reason why not". If we were to bring someone in, who? We have recently been transferred from Bulb to Octopus and they are very keen on heat pumps. I was given the email address of their heat pump team and will contact them in case they can help. Link to comment Share on other sites More sharing options...
sharpener Posted June 9, 2023 Share Posted June 9, 2023 Good, it doesn't sound like an underlying comms problem. Let us know if re-pairing solves the Marlec issue. 15 minutes ago, Judith said: The engineer from our electricians has attempted to solve this by altering the target temperatures of the heat pump and the second immersion. And for a while in the winter that worked, i.e. it went for a week or so without going to error message. Right now, I can reset it and it starts to run again, but that only lasts an hour or so. Can we compartmentalise the problems a bit more. Is the above behaviour the same if you isolate the supply from the diverter to #2 immersion at the dp switch or spur box which I assume they have fitted (I am wondering if the Joule can detect the voltage coming from the Marlec)? What has happened between it running for a week and it running for 1 hour? Have you got a record of the settings after this engineer's visit and can you check they are still the same as he left them? What exactly does the error message say? Are these the right instructions for yr Joule Aero? See 1. interpretation of error codes p 36, 2. configuring the legionella cycle p32. What happens if you disable it temporarily to eliminate it as a factor? Or try a factory reset (note all the settings first, then add them back one at a time and re-test as you go) There doesn't seem to be anything about fitting the second immersion in the text or the exploded view on p41. Is it external like a Willis heater? Can you post a pic of how/where it is installed and the wiring to it. Whereabouts in the country are you? Link to comment Share on other sites More sharing options...
Judith Posted June 9, 2023 Author Share Posted June 9, 2023 2 hours ago, sharpener said: Good, it doesn't sound like an underlying comms problem. Let us know if re-pairing solves the Marlec issue. Can we compartmentalise the problems a bit more. Is the above behaviour the same if you isolate the supply from the diverter to #2 immersion at the dp switch or spur box which I assume they have fitted (I am wondering if the Joule can detect the voltage coming from the Marlec)? What has happened between it running for a week and it running for 1 hour? Have you got a record of the settings after this engineer's visit and can you check they are still the same as he left them? What exactly does the error message say? Are these the right instructions for yr Joule Aero? See 1. interpretation of error codes p 36, 2. configuring the legionella cycle p32. What happens if you disable it temporarily to eliminate it as a factor? Or try a factory reset (note all the settings first, then add them back one at a time and re-test as you go) There doesn't seem to be anything about fitting the second immersion in the text or the exploded view on p41. Is it external like a Willis heater? Can you post a pic of how/where it is installed and the wiring to it. Whereabouts in the country are you? There is no dp switch or spur between the diverter and the Joule. I am doing some long-overdue diagnostics while the iBoost doesn't switch the machine on when the sun comes out. (The manual overrride does work.) I am seeing how long the Joule will stay on in heat pump mode. I cleared the error message by holding OK, as I have done so often. The error message is always E11, i.e. "probably something serious, ask an expert". Now the display is showing the water temperature, 56.9 deg. I will check it a couple of times this evening. The heat pump is timed to come on at around 18:00, and during the evening we will probably have used enough hot water so that it should. If all goes well we will have hot water in the morning. Your link to the instructions didn't work for me. The second immersion is not external. This is the only photo I can take that might give you any information. I suspect that the black flex is the usual feed to the unit, while the white one that bypasses the switch and goes into the back of the machine comes from the iBoost. We are in Brighton. Many thanks for your advice. Link to comment Share on other sites More sharing options...
sharpener Posted June 9, 2023 Share Posted June 9, 2023 Hi Judith, 50 minutes ago, Judith said: your link to the instructions didn't work for me. Try this link then https://totalhomeshop.co.uk/CLI/THE001/Images/Group-Aero-Install-Manual-March-2017Web.pdf If these are right for your unit then E11 denotes a fault in the refrigerant circuit so it may need re-gassing. 49 minutes ago, Judith said: The second immersion is not external. This is the only photo I can take that might give you any information. I suspect that the black flex is the usual feed to the unit, while the white one that bypasses the switch and goes into the back of the machine comes from the iBoost. Looking at that pic I wonder if there is no physical 2nd immersion and what he has done is wire a second direct connection into the original immersion heater. This might be OK but either piece of kit might object to the other. The illustrations in the above handbook don't show any port for a second immersion. The diagram on p17 for solar heating appears to be connections for solar thermal pipework, not electrical connections: Sorry but Brighton is a long way from my patch but am happy to help remotely. Link to comment Share on other sites More sharing options...
Judith Posted June 12, 2023 Author Share Posted June 12, 2023 On 09/06/2023 at 18:11, sharpener said: Hi Judith, Try this link then https://totalhomeshop.co.uk/CLI/THE001/Images/Group-Aero-Install-Manual-March-2017Web.pdf If these are right for your unit then E11 denotes a fault in the refrigerant circuit so it may need re-gassing. Looking at that pic I wonder if there is no physical 2nd immersion and what he has done is wire a second direct connection into the original immersion heater. This might be OK but either piece of kit might object to the other. The illustrations in the above handbook don't show any port for a second immersion. The diagram on p17 for solar heating appears to be connections for solar thermal pipework, not electrical connections: Sorry but Brighton is a long way from my patch but am happy to help remotely. On 09/06/2023 at 18:11, sharpener said: Hi Judith, Try this link then https://totalhomeshop.co.uk/CLI/THE001/Images/Group-Aero-Install-Manual-March-2017Web.pdf If these are right for your unit then E11 denotes a fault in the refrigerant circuit so it may need re-gassing. Looking at that pic I wonder if there is no physical 2nd immersion and what he has done is wire a second direct connection into the original immersion heater. This might be OK but either piece of kit might object to the other. The illustrations in the above handbook don't show any port for a second immersion. The diagram on p17 for solar heating appears to be connections for solar thermal pipework, not electrical connections: Sorry but Brighton is a long way from my patch but am happy to help remotely. On 09/06/2023 at 18:11, sharpener said: Hi Judith, Try this link then https://totalhomeshop.co.uk/CLI/THE001/Images/Group-Aero-Install-Manual-March-2017Web.pdf If these are right for your unit then E11 denotes a fault in the refrigerant circuit so it may need re-gassing. Looking at that pic I wonder if there is no physical 2nd immersion and what he has done is wire a second direct connection into the original immersion heater. This might be OK but either piece of kit might object to the other. The illustrations in the above handbook don't show any port for a second immersion. The diagram on p17 for solar heating appears to be connections for solar thermal pipework, not electrical connections: Sorry but Brighton is a long way from my patch but am happy to help remotely. Hello again. The manual you linked to seems to be a later version of what we have. I've been observing what happens to the Joule. Even though I haven't yet fixed the error in the diverter it is still going to Error 11, never immediately, but often, and always during the night. I found previous notes where the electrician/heat pump person thought it was happening whenever the temperature went above 60, but that is not the case, as it has been at 62 and remained on for an hour or more. We definitely had a further immersion fitted into the tank, as my partner remembers it being shown to us; he says it looked like "a long piece of copper". I am going to carry on a little longer getting data and also try to see what the programme is doing, whether it is cutting out whenever the heat pump is being called on. I suspect it is probably not a question of regassing, unless that could have been the issue from the start. Three supposed experts have looked at it and all assumed that it was the attempt to control it by the iBoost that was the problem. Link to comment Share on other sites More sharing options...
DanDee Posted June 12, 2023 Share Posted June 12, 2023 Have you tried to heat up the tank from cold only on HP to see what happens? Link to comment Share on other sites More sharing options...
sharpener Posted June 12, 2023 Share Posted June 12, 2023 50 minutes ago, Judith said: We definitely had a further immersion fitted into the tank, as my partner remembers it being shown to us; he says it looked like "a long piece of copper". So where/how was it installed? The tank in this illustration has only one boss for the immersion heater 64, about half way up behind 63 the front cover. 65 is the thermostat not a second heating element. Can you take a pic which shows where the black and white wires go into the tank? I think you need to disconnect the Marlec diverter completely to test if there is an underlying fault in the Joule itself, as @DanDee suggests. l Link to comment Share on other sites More sharing options...
Judith Posted June 12, 2023 Author Share Posted June 12, 2023 3 hours ago, DanDee said: Have you tried to heat up the tank from cold only on HP to see what happens? Thank you. As far as I can see at the moment it is not heating up at all on HP only. But I need to take some time to understand the programming system in the manual, to understand when it is meant to be coming on. I might be able to do that tomorrow. Link to comment Share on other sites More sharing options...
Judith Posted June 12, 2023 Author Share Posted June 12, 2023 2 hours ago, sharpener said: So where/how was it installed? The tank in this illustration has only one boss for the immersion heater 64, about half way up behind 63 the front cover. 65 is the thermostat not a second heating element. Can you take a pic which shows where the black and white wires go into the tank? I think you need to disconnect the Marlec diverter completely to test if there is an underlying fault in the Joule itself, as @DanDee suggests. l I will try to see. It was someone sent by Joule who fitted it, after the original person who set the machine up couldn't understand why it wasn't working properly (although he had gone through the steps in the manual and signed them off). There's a complication in who is ultimately responsible. Our contract was with a medium-sized electrical contractor who fitted the PV roof and the iBoost. But they bought the Joule from a smaller heat pump specialist company. They were all very nice people and we trusted them to get the teething troubles ironed out. But now the heat pump specialists, who never knew much about the Joule in the first place, have pulled out of air-source and are doing ground-source HPs only. The senior guy from the electrical contractor, who has tried the most to understand what is wrong, has given up on trying to get any info out of Joule. I probably need to contact him again, but they will charge full-whack even for a non-emergency call-out, so I am trying to understand as much as possible by myself beforehand. With the help of people here, much appreciated. Link to comment Share on other sites More sharing options...
SteamyTea Posted June 12, 2023 Share Posted June 12, 2023 4 hours ago, Judith said: he says it looked like "a long piece of copper". Sounds more like a thermostat than a heating element. Most thermostats have a safety cut out, could be that has tripped. Some are resettable. It may look a bit like this. Link to comment Share on other sites More sharing options...
sharpener Posted June 12, 2023 Share Posted June 12, 2023 Yes, in the diagram compare 65 which is the system thermostat and has a single prong with 64 which is the immersion heater and has a folded element (and usually a separate single probe which is its own thermostat). Link to comment Share on other sites More sharing options...
TonyT Posted June 12, 2023 Share Posted June 12, 2023 More pictures are required the only picture showing the switch looks questionable, and love the grey t&e clips on the flex. Another quality install! Link to comment Share on other sites More sharing options...
Judith Posted June 14, 2023 Author Share Posted June 14, 2023 I'll try and get more pics and more info. Link to comment Share on other sites More sharing options...
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