I've noticed poor performance and I checked the pump flow settings, they're all set at 5. In the commissioning wizard this shows as 5L/min, this seems very low! Brand new install so I am contacting the installer too but won't get an answer till the morning...
Most heat pumps need a flow of 25-30 litres minute, so there’s definitely an issue there. I’m surprised it’s not errored and shut down. Ours shuts down if flow drops below 22 litres per minute.
Most heat pumps need a flow of 25-30 litres minute, so there’s definitely an issue there. I’m surprised it’s not errored and shut down. Ours shuts down if flow drops below 22 litres per minute.
It did overnight with an L9 error, 1st time, I can reset it, it runs for an hour and then same error again which led me to check the flow rate. Pressure looks good, no leaks, pump speed at max so something seems wrong...
@paulrlondon, one of the causes of our initial flow errors was a blocked filter with debris and gunk from the heating circuit getting trapped in the filter and subsequently dropping the flow. You'll almost certainly have a filter somewhere. If you know where it is, stop you system, and open the filter, and give it a wash/clean. This may not be the cause, but it's worth a look.
I've created a brief tutorial video demonstrating how I cleaned the filter on our heat pump. After filming the video, we realised the filter was quite hard to reach and access, so we had our installers relocate it indoors for easier access. Its location can vary, so I hope you're familiar with where yours is situated.
@paulrlondon So an L9 error is low flow warning, which could be a sensor error. Just to check, you have enough radiators drawing heat at the moment? I had a similar error when installing mine as I forgot to open all the radiator valves. Worth posting a picture of your pump and its current setting also.
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
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Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
I've just cleaned the filter with the magnetic rod, there was some black bits in there but not a lot. I found a few YouTube videos suggesting there may be another filter above the pump but I don't appear to have one.
If I reset the error and let the system come on, the Flow pipe from the ASHP is warm, if I follow that it gets to a 3 way junction splitting between the UFH and radiators. The UFH flow pipe is warm. The radiator flow pipe is cold. There's a Honeywell home zone valve a little further along that pipe, it's set to auto and calling for heat, I tried manual open but made no difference.
Hi Jake, yes I have an external pump too. It's set to 3, and both DHW and heating are set to 5. I experimented putting DHW and heating to 4, the flow rate apparently dropped to 0L!
I've noticed poor performance and I checked the pump flow settings, they're all set at 5. In the commissioning wizard this shows as 5L/min, this seems very low! Brand new install so I am contacting the installer too but won't get an answer till the morning...
The high delta T (difference between THW1 and THW2) also supports a too low flow rate. Are all the ufh/radiators all getting warm? Even at an average flow temp of 35 deg or so they should feel warm to the touch.
Do you have any sort of buffer, low loss header or similar?
Fixed by the installer. It was a filter blockage, this filter was within the ASHP unit outside. A piece of plumbing sealant, must have worked its way lose from one of the new radiators being installed. Flow rate back up to 16 now
