Thank you. 

In my defence, the cycling was much much worse ( think 4 complete off heat pump in 3 hours and the time used in each area/ñ for space/water/off was 60% off) before I tinkered with the heat curve yesterday- so the Heat Geek advice has helped on that score. 

I’ve just been and reset the main controller/timer with a slightly adjusted temp and the room stat/controller has now automatically picked that up, so perhaps it’s whatever I used last to adjust the temp? 

Yes 15/17 is on the cool side- we’re really used to old/leaky houses by now so it’s fairly usual for us.  The room where the stat is is colder than most of the rest of the house, but that’s where we spend most of our time.  18 overnight made the bedrooms very warm when the heat pump kicked in properly around 4am.  

The installer had 20 during the day and 10 overnight. That would be fine for us overnight temp wise but not sure that’s most effective for the heat pump. 

I’m going to leave the settings as is for 24 hours now to see what happens.  I’ve just got it set on weather compensation, so I’ll see if that works overall.  If we get a good steady set of flow temps ( I will look out for the heating of the water now) then I’ll think about setting the room/curve setting and see how that affects things. It’s very tricky when you can’t see the energy consumptions 

I can’t tell you how much I appreciate your help. 

@cheshirecat

I assume that you don't have a Smart meter. You could take daily reading from your electricity meter which should give some indication of energy usage.

I’ve not given in to the smart meter yet.  

The longer plan is to add in solar and at that point I might be forced to.  

I’ve been taking readings every few hours for the last few days, but we have an electric car that skews the readings as it’s a PHEV and needs charging daily/more than daily.  

I know what the average consumption has been over the last few years, so over a period I should be able to get an average.  

Posted by: @cheshirecat

↑

Thank you. 

In my defence, the cycling was much much worse ( think 4 complete off heat pump in 3 hours and the time used in each area/ñ for space/water/off was 60% off) before I tinkered with the heat curve yesterday- so the Heat Geek advice has helped on that score. 

I’ve just been and reset the main controller/timer with a slightly adjusted temp and the room stat/controller has now automatically picked that up, so perhaps it’s whatever I used last to adjust the temp? 

Yes 15/17 is on the cool side- we’re really used to old/leaky houses by now so it’s fairly usual for us.  The room where the stat is is colder than most of the rest of the house, but that’s where we spend most of our time.  18 overnight made the bedrooms very warm when the heat pump kicked in properly around 4am.  

 

The installer had 20 during the day and 10 overnight. That would be fine for us overnight temp wise but not sure that’s most effective for the heat pump. 

I’m going to leave the settings as is for 24 hours now to see what happens.  I’ve just got it set on weather compensation, so I’ll see if that works overall.  If we get a good steady set of flow temps ( I will look out for the heating of the water now) then I’ll think about setting the room/curve setting and see how that affects things. It’s very tricky when you can’t see the energy consumptions 

I can’t tell you how much I appreciate your help. 

 

Another 14kW Ecodan user here.  I've only just installed the wireless controller so I'm not sure yet how it interacts with the main controller, especially with timer settings.  

The sort of cycling you are describing (4 stops in 3 hours) isn't really cycling that you need to worry about; it sounds more like the system switching off when the set room temperature is met.  4 stops in 3 hours is good.

If you are using room temperature mode and a Mitsubishi wireless controller  (it sounds like you are) and the system is set to 'auto adaptation' (this is the default and set by a dip switch) then in my experience the weather compensation curve is ignored a lot of the time.  It doesn't seem to matter what you set the curve at, it does its own thing, especially when heating up a cold house. 

The sort of cycling that is bad is multiple times per hour.  3 times per hour is generally considered OK. 

Thank you. 

I think not knowing what the COP is doing and no indication of usage is what I’m finding most concerning. 

If 3 cycles/4 hours is ok, then that’s pleasing. 

I’m trying to find a happy medium of warm home to electric consumption. 

The house used 32000 kWh roughly of oil last year, so 10000 kWh of electric is where I need to be- current consumption is roughly 13000 kWH estimated- so I’m watching like a hawk at the moment. 

@cheshirecat 

you can get energy consumed and delivered directly from the wired in controller.  Have you tried that? 

If you are running room temp mode with auto adaptation the radiator temperature varies a lot.  When it's trying to heat the house up it definitely puts comfort above economy and bumps up the flow temp 55 deg.  I've never seen my ASHP use so much power.  I can't check at the moment because Melcloud seems to be broken but I doubt this is economical. 

Posted by: @kev-m

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If you are running room temp mode with auto adaptation the radiator temperature varies a lot.  When it's trying to heat the house up it definitely puts comfort above economy and bumps up the flow temp 55 deg.  I've never seen my ASHP use so much power.  I can't check at the moment because Melcloud seems to be broken but I doubt this is economical. 

 

 

Hi Kev,

I am assuming that you have only recently switched on the auto adaptation function.

In industrial systems, the controller parameters have to be adjusted to match the response time of the process, otherwise there can be large fluctuations in the system operation.

The auto adaptation system does not have any obvious method for the internal parameters of the controller to be adjusted by the operator, I must therefore assume that there is some form of self tuning algorithm built into the controller, which because of the relatively long response times within a home heating system, may take quite some time to adjust the controller parameters to match your system.

Initially you may find that it varies the LWT by larger than normal values, but these variations should reduce as the controller adjusts to your home.

My problem is I don’t really know what at tweak to sort it out, or what the best settings are for the house we have. Or do you think the settings will sort themselves out.  My flow/return is only 2 or 3 degrees and everything I can find says it should be more? 

As far as I can tell the installation should have included energy- but they told me that there’s a problem getting the parts so I don’t have it. 

I’ve not had a fantastic experience with the install service.  Not the installers themselves, but the company as a whole. 

I’m not convinced they want my heat pump to be efficient and cheap to run- more that they want me to have a warm house and them to not get called back. 

Posted by: @cheshirecat

↑

My problem is I don’t really know what at tweak to sort it out, or what the best settings are for the house we have. Or do you think the settings will sort themselves out.  My flow/return is only 2 or 3 degrees and everything I can find says it should be more? 

As far as I can tell the installation should have included energy- but they told me that there’s a problem getting the parts so I don’t have it. 

I’ve not had a fantastic experience with the install service.  Not the installers themselves, but the company as a whole. 

I’m not convinced they want my heat pump to be efficient and cheap to run- more that they want me to have a warm house and them to not get called back. 

If you have been charged for the energy monitoring equipment, then insist that it is installed or that you receive a refund. It is only by us customers insisting on good service, will we get it.

They say they will, but it’s not available at the moment.  I definitely cannot see any energy data in the Mitsubishi controller I have unless it is buried in the menus for installers. 

I know I sound clueless, that is because I am. 

I don’t understand how my system works and I’m finding it very frustrating. 

I don’t really understand what I need to do to reduce the power it’s consuming, but without the energy data - I’m flying blind so tweaking things doesn’t really help me. 

I’ve read quite a lot, so understand a bit about how heat pumps work, but on an hourly basis the flow return difference is 2/3 degrees- everything I’ve read suggests that should be 5 or more- but how can I influence that? 
The house is either cold or too hot, and with no rhyme or reason.  Perhaps the system is learning? 

We have consumption ( total house) of an average of 58 kWh per day( recent install so cold ish weather)  Prior to ashp install that was around 21 kWh per day. ( We have an EV) 

Hot water programmed to heat to 50 twice a day- middle of the night and mid-afternoon- we either use very little hot water, or loads ( loads on the odd day when one of the teens decides to have a bath.) 

The room stat is set at either 17 ( too cold) or 18 ( too warm). 

I don’t know where to start in making the system work well for us, or whether 38kWh in this weather is what I should expect given our previous oil consumption ( av 3200litres/yr). 

The house is a leaky sieve, but we are working on that.  

I just don’t know how the heat pump is performing and whether it’s as good as it’s getting. 

@cheshirecat

Ask your installer for a detailed list of the equipment that is still to be installed, so that we can check on its availability.

Try watching the YouTube video below which explains some of the capabilities of the MelCloud system.

The video below provides more details of how the controller should be adjusted.

https://www.youtube.com/watch?v=RX31v4NoQf4

Have a watch and come back with any questions.

@cheshirecat do you have a low loss header? That might be contributing to your issue by returning warm water directly back to the heat pump.