# Daikin HP, frost cycling stopping hot water heat up **URL:** \ **Category:** Heatpump\ **Created:** [8 January 2025 07:45 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632 "2025-01-08T07:45:23Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [8 January 2025 07:45 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/1 "2025-01-08T07:45:23Z")
Has anyone else had a issue with hot water heating up because of frost cycles ? i have had to resort to turning off the HP hot water schedules when when its below 2 degrees C because the hot water does not come back on after the first hot water cycle (stopped by defrost) the hp stays on central heating, when its warmer outside the heat pump manages to heat hot water with no issue , now im using the emersion heater to heat the hot water unfortunately it that high up in the tank i dont have enough hot water for the family rush on showers before school and work does anyone have any ideas how this can be resolved ![image](https://community.openenergymonitor.org/uploads/default/original/3X/4/8/4808e6d1f72969ba9b87b5df6d45a83a2eb6b437.jpeg) the hot water schedule should be on until 4:30 am if the hot water is not hot enough ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [8 January 2025 08:00 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/2 "2025-01-08T08:00:24Z")
Mine just resumed heating the hot water where it left off ![Screenshot_20250108-075810](https://community.openenergymonitor.org/uploads/default/original/3X/1/3/1371d96868ef3050a207ef4468df16b323ad1ab0.png) I guess you could have two separate dhw cycles in that period, rather than one big one ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [8 January 2025 08:03 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/3 "2025-01-08T08:03:15Z")
i think mine used to do this, maybe i have changed a setting somewhere without realising it, are you using quiet mode ? maybe there is a setting somewhere that makes heating a priority will check through later ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [8 January 2025 08:12 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/4 "2025-01-08T08:12:37Z")
Not using quiet mode and currently running as Octopus engineer left things (to prove a point), so nowt fancy set. The defrosts turned last night into a bit of a dogs dinner for steady state running though. ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [12 January 2025 16:49 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/5 "2025-01-12T16:49:44Z")
I might have had something similar today. Showers have been noticeably cold today and the hot water cycle was interrupted by a defrost and failed to resume. ![Screenshot_20250112-164708](https://community.openenergymonitor.org/uploads/default/original/3X/a/c/ac3188498303d122d8bf3b10be688407c2ca4c8e.png) ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [12 January 2025 16:57 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/6 "2025-01-12T16:57:00Z")
![Screenshot_20250112-165559](https://community.openenergymonitor.org/uploads/default/original/3X/f/6/f6e32bd2367b01a90a131055919bd5f855be4498.png) ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [12 January 2025 17:05 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/7 "2025-01-12T17:05:07Z")
yep that looks the same Mark ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [12 January 2025 17:20 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/8 "2025-01-12T17:20:39Z")
yep the defrost cycle comes from the central heating so the 3 port valve moves back to central heting , the issue with the daikin system the hot water is only triggered by the start of the heating schedule, its the same with central heating so the only way round this is to use the reheat mode ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [12 January 2025 17:24 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/9 "2025-01-12T17:24:10Z")
It’s as if it forgot what it was doing before the defrost. But to it’s credit what followed was a lovely long steady state operation. Before reaching a balmy 6C outside and then returning to cycling. Note the big target steps are the Octopus suggested Madoka modulation of 10 while using the default Octopus curve, which is an excellent way to highlight heat loss might not be what was calculated. ![Screenshot_20250112-171927](https://community.openenergymonitor.org/uploads/default/original/3X/a/2/a22c02ddb87ee893f8960f155951d75ffc9cd50c.png) ---
**Author:** ![divenal](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/d/b9bd4f/32.png) [@divenal](https://community.openenergymonitor.org/u/divenal)\ **Post date:** [12 January 2025 18:05 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/10 "2025-01-12T18:05:19Z")
> [@Chris\_Hill](#): > > the issue with the daikin system the hot water is only triggered by the start of the heating schedule Or schedule back-to-back heating modes? Eg comfort at 2am, 2:30am, 3am, and then off at 4am ? I just decided to use the api to trigger a boost prior to the heating cycle on the really cold nights, so that the HP could concentrate on room-heating. Only COP of 1, but perhaps it will save elsewhere by not interrupting heating stability. ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [16 January 2025 11:21 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/11 "2025-01-16T11:21:42Z")
Last night produced the worst defrosting I have seen on my 11kW. Note that it had no issues resuming the hot water cycle and happily got up to temp. ![image](https://community.openenergymonitor.org/uploads/default/original/3X/f/0/f094cd4e0b305555845c8481c73d5aebb9b1f109.jpeg) ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [16 January 2025 11:29 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/12 "2025-01-16T11:29:56Z")
must of been some high humidity periods , ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [16 January 2025 11:36 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/13 "2025-01-16T11:36:34Z")
woke up to freezing fog… with the temperature and dew point converging ![image](https://community.openenergymonitor.org/uploads/default/original/3X/1/6/16f5eb35cf88c2122fb3e4db3350055d2c159559.png) ---
**Author:** ![Stuart\_Nicol](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/s/d6d6ee/32.png) [@Stuart\_Nicol](https://community.openenergymonitor.org/u/Stuart_Nicol)\ **Post date:** [27 December 2025 16:44 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/14 "2025-12-27T16:44:42Z")
Hi Chris did you find a solution for this? As I’m currently having the same issue thanks ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [27 December 2025 17:01 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/15 "2025-12-27T17:01:10Z")
I do not think its possible to stop it completely when using the heat pump for hot water , we have to reduce or delay it , as for hot water i have decided to use my tank immersion heater below 2 degree C instead of the heat pump , especially through the night , the hard working of the heat pump seems to make the issue worse ---
**Author:** ![Stuart\_Nicol](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/s/d6d6ee/32.png) [@Stuart\_Nicol](https://community.openenergymonitor.org/u/Stuart_Nicol)\ **Post date:** [27 December 2025 17:28 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/16 "2025-12-27T17:28:20Z")
cheers the reply, can’t understand why it forgets that the DHW is on, can I ask how you’re setting the immersion heater element of the tank off at lower temps? ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [28 December 2025 06:41 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/17 "2025-12-28T06:41:23Z")
i am using home assistant to turn off the hot water and force the element on at a certain time if the hot water is below xx degree C ![image](https://community.openenergymonitor.org/uploads/default/original/3X/c/0/c0d34ba6e4902be47764de373f680a4a7352f25e.png) esense is my hot water element in tank ![image](https://community.openenergymonitor.org/uploads/default/original/3X/7/e/7edf04aee542a9add88eefaacb93b9b49b455d52.png) this also guarantee hot water if something goes wrong with the hot water cycle ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [31 December 2025 07:39 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/18 "2025-12-31T07:39:22Z")
![image](https://community.openenergymonitor.org/uploads/default/original/3X/4/3/43bff5c122ab6c0456cf7e6eaed77c57640d33da.png) this is when i have reduced my target LWT from the wc to -3 degree C which has helped reduce the defrost cycles ![image](https://community.openenergymonitor.org/uploads/default/original/3X/6/c/6cef4ce420f58263fcb13965121323940e056e7b.png) then the lwt recovers later and the internal temps do not take a hit ---
**Author:** ![Chris\_Hill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/chris_hill/32/27079_2.png) [@Chris\_Hill](https://community.openenergymonitor.org/u/Chris_Hill)\ **Post date:** [31 December 2025 08:15 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/19 "2025-12-31T08:15:25Z")
i would like to lower the LWT before the defrost cycle happens but need a way of triggering this , if anyone has any ideas ?? ---
**Author:** ![Mld](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/mld/32/31750_2.png) [@Mld](https://community.openenergymonitor.org/u/Mld)\ **Post date:** [31 December 2025 08:59 UTC](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632/20 "2025-12-31T08:59:43Z")
Defrost hell here. -4C and freezing fog ☹ Getting a defrost every 45 mins. ![PXL_20251231_083236494](https://community.openenergymonitor.org/uploads/default/original/3X/7/4/7480afe5df464eef221961fe5b89abfb838be11e.jpeg) [Next page](https://community.openenergymonitor.org/t/daikin-hp-frost-cycling-stopping-hot-water-heat-up/27632.md?page=2)