DHW COP of 3.4 this morning. (2.8 yesterday)
Heated water from 14.5°C to 43.5°C
Flow rate peaked at 55°C
Two hours not quite long enough for it to reach the target temp of 48°C in Eco mode.
Check what you got DHW anti cycling time set to. If you put this to 0 it should run past 2 hours if required.
It will be interesting to see it run to completion to see what flow/return ends up at. You’d hope that you can set it to be not too much past 48C eventually.
Much nicer COP though. 
Something wonky goes on with flow rate on the graph though? Have you got any air in the system?
Graphs suggest that erratic flow rate has been there for a while. Only with DHW though.
New cylinder coming in a couple of weeks so will ask the installer when he returns.
Yep, common issue. Usually air in the system.
Have a look around the site so you’re armed with the right info.
heat meter location and air valves etc.
You need to get this sorted as it can screw output (and cop) data. See how the heat output drops at 03:20 there in line with lack of flow reading.
flow x dt x shc = output.
if the input values aren’t there, the output comes out screwy.
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We got an efficiency of 3.17 to heat our 300L tank to 52c.
We set the flow temp to 4C over the tank temp. So it does take a while to heat up.
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@gck303 could you explain how you set the flow temp for the DHW? Am I correct that you have an Ecodan?
I have a loxone miniserver that controls the ecodan (via modbus), circulator and the CH/DHW valves. The miniserver sets the flow temp and operates the valves based on demand.
The miniserver collects the Kamstrup data (via modbus) and publishes it via MQTT after splitting it into DHW/CH based on what is operating. See my feeds below.
Ah, so I’m assuming the Ecodan has no idea that you have switched from heating to hot water and back it is just delivering a fixed flow temp that you are changing when needed?
It has no idea. It is just heating the water to the temperature requested.
I only use two things on the ecodan controller via modbus:
- on/off control
- temp flow
All the relays and external controls on the FTC are unused.
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