# HeatPumpMonitor - DHW efficiency **URL:** \ **Category:** Applications\ **Created:** [2 January 2024 13:32 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257 "2024-01-02T13:32:46Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![LeiChat](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/l/df788c/32.png) [@LeiChat](https://community.openenergymonitor.org/u/LeiChat)\ **Post date:** [6 January 2024 09:38 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/22 "2024-01-06T09:38:51Z")
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. ![image](https://community.openenergymonitor.org/uploads/default/original/3X/1/e/1efdd9653b18cb1db2ad97035e71c102865add92.jpeg) ---
**Author:** ![Zarch](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/zarch/32/7947_2.png) [@Zarch](https://community.openenergymonitor.org/u/Zarch)\ **Post date:** [6 January 2024 09:57 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/23 "2024-01-06T09:57:42Z")
> [@LeiChat](#): > > 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? ---
**Author:** ![LeiChat](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/l/df788c/32.png) [@LeiChat](https://community.openenergymonitor.org/u/LeiChat)\ **Post date:** [6 January 2024 10:08 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/24 "2024-01-06T10:08:10Z")
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. ![image](https://community.openenergymonitor.org/uploads/default/original/3X/9/c/9c52183fbb123e3245dfd5e203fea08600ae7d1c.jpeg) ---
**Author:** ![Zarch](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/zarch/32/7947_2.png) [@Zarch](https://community.openenergymonitor.org/u/Zarch)\ **Post date:** [6 January 2024 10:17 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/25 "2024-01-06T10:17:15Z")
> [@LeiChat](#): > > Graphs suggest that erratic flow rate has been there for a while. Only with DHW though. Yep, common issue. Usually air in the system. Have a look around the site so you’re armed with the right info. > [@Sharky 775 heat meter questions](https://community.openenergymonitor.org/t/sharky-775-heat-meter-questions/21591): > > Hello everyone. I will shortly be having an Arotherm+ ASHP (7kW) installed onto a new system and want to get monitoring kit ready. I already have some SDM120 meters and can talk to them with Python. I’m looking at the Sharky 775 (2.5m3 nominal flow) from Stockshed with MBus module, which looks like it has acceptable pressure (head) loss at max ASHP flow and seems to be one of the most accurate meters. Before I press the button on it, does anyone have any wise words on this meter, and also is … > [@Kamstrup Multical 403 Erratic flow readings](https://community.openenergymonitor.org/t/kamstrup-multical-403-erratic-flow-readings/24206): > > I’m running the Kamstrup Multical 403 on my setup 7kW aroTHERM+ (Rushden, Northamptonshire on Heat Monitoring Dashboard), installed early July 2023. I too have issues with DHW reporting which we are looking into. It shows the same erratic recording of flow temperatures. Photo of setup: 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. ---
**Author:** ![gck303](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/gck303/32/9889_2.png) [@gck303](https://community.openenergymonitor.org/u/gck303)\ **Post date:** [24 January 2024 11:46 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/26 "2024-01-24T11:46:28Z")
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. ![2024-01-24 11_44_55-Window](https://community.openenergymonitor.org/uploads/default/original/3X/0/b/0b68da443bd6967c4deef15afd5103d2a13476a2.png) ---
**Author:** ![ajdunlop](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/a/6bbea6/32.png) [@ajdunlop](https://community.openenergymonitor.org/u/ajdunlop)\ **Post date:** [24 January 2024 11:57 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/27 "2024-01-24T11:57:50Z")
@gck303 could you explain how you set the flow temp for the DHW? Am I correct that you have an Ecodan? ---
**Author:** ![gck303](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/gck303/32/9889_2.png) [@gck303](https://community.openenergymonitor.org/u/gck303)\ **Post date:** [24 January 2024 12:34 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/28 "2024-01-24T12:34:09Z")
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. ![2024-01-24 12_31_14-Window](https://community.openenergymonitor.org/uploads/default/original/3X/0/8/08572a4a2c13869ac5ad5e8da74993963a25a29f.png) ---
**Author:** ![ajdunlop](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/a/6bbea6/32.png) [@ajdunlop](https://community.openenergymonitor.org/u/ajdunlop)\ **Post date:** [24 January 2024 12:42 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/29 "2024-01-24T12:42:21Z")
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? ---
**Author:** ![gck303](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/gck303/32/9889_2.png) [@gck303](https://community.openenergymonitor.org/u/gck303)\ **Post date:** [24 January 2024 12:46 UTC](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257/30 "2024-01-24T12:46:08Z")
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. [Previous page](https://community.openenergymonitor.org/t/heatpumpmonitor-dhw-efficiency/25257.md?page=1)