majlb

Long time lurker, first time poster. Also a bit of a hijack, but I have a similar issue. Happy to repost as a new thread if deemed appropriate. I have a 12 kW LG unit, fitted spring 2022. Turns out it's probably slightly oversized for my house, I think I would have been fine with the 9kW, which may have also helped my short cycling and occasional low-flow warning issues. But anyway, I've noticed some CH14 errors which don't seem to be of much consequence to the operation of my unit, but this forum seemed like a good place to discuss and try to resolve. See below. i was checking the control unit box looking at energy use and on-off records, to try and understand short cycling behaviour of the unit, and noticed I had some CH14 fault codes from that day. I generally have no operational issues with the unit, so this was a surprise. Knowing this is linked to low flow, and having read around, was monitoring the flow rate by looking at the display, and saw the flow rate drop from around 30 to 15 L/min, and then threw a CH14 error in front of me. So it seems like it was triggered by the system reducing the flow rate to provide the heat requirement, below a min acceptable level. Playing around trying to understand this, I realized that you can specify the water flow control method, which was set to either optimal or fixed delta T. But I experimented and changed this to pump capacity mode and set 80% and 100%. No additional CH14 errors have since been thrown. I presume the flow rate was being reduced to an optimal level for the heat requirement, but gets to a certain level which is too low and then throws the error. So it seems like the control software allows too low a flow rate. I'm not sure of the effect on the unit's behaviour if I specify the water flow by the pump capacity. I presume if I set it to 100% it will short-cyle more when there is a low heat requirement. And in cooler weather, I'd be artificially limiting the heat delivered. I'm unsure what else can be modulated in the unit to produce less heat . I'm also not sure of if throwing CH14 errors is of much consequence in my case, if the system seems to reinitialise and continue operating successfully. I did notice very occasionally the hot water hadn't operated and tank was cold, but unsure if that's related. If throwing a CH14 error isn't of much consequence if the system continues to operate, I may as well leave it and have optimal flow behaviour with some CH14 errors, rather than a manually applied x% flow capacity defined and inefficient operation. Michael_S, I presume this is all not relevant for you as you have a different control box?