Steve W Posted December 8, 2022 Share Posted December 8, 2022 As I primarily use my ASHP using Economy 7 / Solar / Batteries I use external controls to determine when the ASHP should produce heat. The external control calls for heat and the ASHP starts and the rotating arrows show the pump is working - this is all as expected. When the house is up to temperature the external control switches off and the rotating arrows stop as expected. The problem is that the ASHP continues to heat the water and circulate it through the bypass valve. No indication is given that the ASHP is running but it cycles and consumes significant power from the batteries. If I turn the water temperature down to 15C this mitigates the problem as it is not hearting the water. The downside is that when the house calls for heat it only gets water at 15C. Am I missing a setting as this is making life very awkward or expensive. Link to comment Share on other sites More sharing options...
ProDave Posted December 8, 2022 Share Posted December 8, 2022 Post more details of your controls and how they connect to the ASHP Link to comment Share on other sites More sharing options...
Steve W Posted December 8, 2022 Author Share Posted December 8, 2022 The controls are largely irrelevant as the final output is a zero volt relay which when closed activates the ASHP external control. The external controls comprise 6 x TADO smart radiator valves and 6 TADO room stats that operate the UFH. Each control is capable of demanding heat. To verify the operation the second pole on the relay switches an LED to provide visual confirmation of the operation. Link to comment Share on other sites More sharing options...
HughF Posted December 9, 2022 Share Posted December 9, 2022 There’s probably a minimum cycle time programmed into the daikin somewhere, and despite removing the call for heat, it still overruns. Have you googled those terms yet? 1 Link to comment Share on other sites More sharing options...
ProDave Posted December 9, 2022 Share Posted December 9, 2022 If you are using an external control, you probably have to adjust a setting or even a switch in the ASHP to tell it to use the external input. Have you checked that has been done? Ideally you want two such extenal inputs, a call for heating and a call for hot water. My experience is few ASHP's offer 2. I had to get creative to effect such a thing with my LG heat pump. The reason for wanting 2 demand inputs is so heating and hot water can operate at different temperatures. Link to comment Share on other sites More sharing options...
Steve W Posted December 10, 2022 Author Share Posted December 10, 2022 Ideally I would like the UFH to be at 35C and then radiators at 45C. I currently have the system programmed to heat the hot water to 45C between 12.30 and 1.30 which it does. I have the UFH set from 12.30 to 6.30 to 35C. If the hot water finishes early, which it does when it has been a sunny day, the UFH starts early. The radiators get heat between 6.30 and 8.30 at 45C as I manually up the temperature. I also give the upstairs a couple of hours from 8.30 and 10.30p.m. The overall performance is good for the time of day that the pump runs. The "Unit Control Method" is set to "Ext RT control" which is "ext RT is used when the system has more than 1 zone, requiring a 3rd party controller. The pump operation mode is set to request. Temperature range us set to 15min and max 55. Emitter type is set to slow UFH. I have a copy of the installation parameters which I will post. Link to comment Share on other sites More sharing options...
Steve W Posted December 10, 2022 Author Share Posted December 10, 2022 Copy of the commissioning settings. Commissioing Daikin - EDLQ.pdf Link to comment Share on other sites More sharing options...
Steve W Posted December 10, 2022 Author Share Posted December 10, 2022 Screenshot from the Daikin App eith LWT SET TO 35C, no demand heat. Not sure why there are two temperatures, climate control 27.1 and heating to 35C. Link to comment Share on other sites More sharing options...
ProDave Posted December 10, 2022 Share Posted December 10, 2022 28 minutes ago, Steve W said: The "Unit Control Method" is set to "Ext RT control" which is "ext RT is used when the system has more than 1 zone, requiring a 3rd party controller. The pump operation mode is set to request. Temperature range us set to 15min and max 55. Emitter type is set to slow UFH. My question remains HOW does the external controller "call for heat" from the heat pump? I would assume a wired connection probably to a volt free contact. I feel this is the bit not working but you have not provided any details yet of how the external controller talks to the heat pump to call for heat. Link to comment Share on other sites More sharing options...
Radian Posted December 10, 2022 Share Posted December 10, 2022 1 hour ago, Steve W said: Not sure why there are two temperatures, climate control 27.1 and heating to 35C. I can only tell you that with my Daikin A/C units the Onecta app shows actual room temperature/humidity and setpoint in those locations: Link to comment Share on other sites More sharing options...
Steve W Posted December 11, 2022 Author Share Posted December 11, 2022 I've attached the wiring diagram from the Daikin installation Guide, the connections inside the controller and the external shot of the 0V relay. There is a green LED that lights when heat is called for. The 0V end has been metered to verify the on/off and that the relay is acutally working. EBLQ05-07CV3-EDLQ04-07CV3_4PEN405544-1D_Installer Reference Guide_English.pdf Link to comment Share on other sites More sharing options...
ProDave Posted December 11, 2022 Share Posted December 11, 2022 The only thing I can pick out from that poor diagram in the manual is that it is expecting terminals 1, 2, and 2a to be used, you only have 2 wires. I wonder if it is expecting a changeover contact rather than an open / close contact? Other than that, if you are SURE the contact is opening and closing (measure the voltage between terminals 1 and 2, relay closed =0V relay open = some higher voltage) then it has to be some setting needed to tell the HP to use the external thermostat. What does the installer say? Link to comment Share on other sites More sharing options...
Steve W Posted December 11, 2022 Author Share Posted December 11, 2022 There is also a video on YouTube Connecting a 3rd party thermostat to a Daikin Altherma unit - YouTube (later part) that definitively confirms that it is 1 and 2 and it is volt free. I have checked that the relay is definitely working (more than once). I probably need a warmish day as at the moment the ASHP is running intermittently (without the display showing its running). Left hand side shows the batteries charging pink and the ASHP running in blue. At 7.30 the system swaps over from Economy 7, hence the pink areas above the line. at 8.30 the heating switches off (as expected). There are then a number of peaks (including the toaster), the later ones correspond to the heat pump running up. It may be the intended operation when the weather is cold? Link to comment Share on other sites More sharing options...
ProDave Posted December 11, 2022 Share Posted December 11, 2022 My LG ASHP when it is "off" will periodically start up the water circulation pump as an ante frost measure, to replace the cold water in the ASHP with something less cold. Is this what you are seeing? It typically takes less than a minute to do that. Link to comment Share on other sites More sharing options...
Steve W Posted December 11, 2022 Author Share Posted December 11, 2022 It appears that it periodically heats the water up and runs the pump. If I knock the water temperature down to 15C it doesn't appear to do anything other than circulate the water (I may be wrong but there aren't any significant blips on the power consumption). It also appears to do this regardless of whether it is switched on or not. I will keep an eye on it. Mechanically the unit seems to work well. From a control point of view it is bizarre, for instance you can program different time periods with temperatures but there isn't an off - best you can do is set it to 15C which means the pump runs constantly pushing around 15C water. Link to comment Share on other sites More sharing options...
ProDave Posted December 11, 2022 Share Posted December 11, 2022 It really sounds to me like it is ignoring the remote call for heat input, and when your heating is "off" it still tries to maintain a now very short loop of pipework up to temperature. I keep hoping someone that knows this particular unit will come along and help you check the settings to make sure it really is reading that input. Link to comment Share on other sites More sharing options...
dpmiller Posted December 12, 2022 Share Posted December 12, 2022 can't say for this particular Daikin, but our Cool Energy has three pump modes selectable in the menu- off, on continuously, and on when working. Obviously it's the latter that's required in most instances. Link to comment Share on other sites More sharing options...
Temp Posted December 12, 2022 Share Posted December 12, 2022 I've no experience with heat pumps but could it be doing this because it's very cold outside? Eg to stop the outside unit freezing up? Link to comment Share on other sites More sharing options...
Steve W Posted January 6, 2023 Author Share Posted January 6, 2023 There appears to be a threshold whereby the ashp heats and circulates hot water when there is no demand, even when heating and water are off. This morning the outside temperature was around 5C and the pipes were warm, other mornings they were cold. As this doesn't seem to make a lot of difference to the running costs I've moved this to mild curiosity from being a concern. It would be useful to have a definitive answer along with the cut in temperature. Link to comment Share on other sites More sharing options...
JamesPa Posted January 6, 2023 Share Posted January 6, 2023 2 hours ago, Steve W said: There appears to be a threshold whereby the ashp heats and circulates hot water when there is no demand, even when heating and water are off. This morning the outside temperature was around 5C and the pipes were warm, other mornings they were cold. As this doesn't seem to make a lot of difference to the running costs I've moved this to mild curiosity from being a concern. It would be useful to have a definitive answer along with the cut in temperature. Sounds like (as Temp suggests) the freeze protection function. It is most likely configurable if you want to switch it off (but I wouldn't unless you have glycol in the system). If it only happens on cold days then almost certainly that. My boiler does this and every ASHP I have read up about also. Link to comment Share on other sites More sharing options...
Steve W Posted January 7, 2023 Author Share Posted January 7, 2023 The system is fitted with anti freeze valves instead of using glycol to ensure that the system is protected against freezing. It would be useful if the protection could be configured as the water is quite warm. Link to comment Share on other sites More sharing options...
JamesPa Posted January 8, 2023 Share Posted January 8, 2023 11 hours ago, Steve W said: The system is fitted with anti freeze valves instead of using glycol to ensure that the system is protected against freezing. It would be useful if the protection could be configured as the water is quite warm. In this case the freeze protection function needs to be left on. I don't know if there is any parameter you can adjust, but I certainly wouldn't turn it off altogether.. The a/f valves are just a backup to the ASHP freeze protection to cover the situation that its both cold and the power has failed. Link to comment Share on other sites More sharing options...
Steve W Posted January 31, 2023 Author Share Posted January 31, 2023 As part of a different problem I had a visit from a Daikin Engineer. The problem with constant cycling / pump running / electricity usage, when there was no demand, has been corrected by altering one or more frost settings. No idea which settings - just glad it no longer happens Link to comment Share on other sites More sharing options...
Steve W Posted April 4, 2023 Author Share Posted April 4, 2023 After a significant amount of digging it appears that if the water temperature drops below 15C that the unit has real problems in cold weather. The optional backup is heater is not so optional especially during defrost cycles. Can Daikin Altherma be delivered without a backup heater? No. The backup heater must be installed to ensure that the water temperature never drops below 59ºF (15ºC) during startup of the system or during defrost. This was in the FAQ for North America. Link to comment Share on other sites More sharing options...
ProDave Posted April 4, 2023 Share Posted April 4, 2023 Is this another "need to keep the compressor warm" type of issue? Similar to Mitsubishi where some models have a sump heater? In this case they keep the compressor warm by continuously running it at a low level? Not all compressor types need this so yet another hidden "feature" buyers need to be aware of if they want to minimise rogue energy use. Link to comment Share on other sites More sharing options...
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