Flow Temperature settings of my Mitsubishi Ecodan heat pump set correctly?

@M.isterW thanks for your reply….I am not trying to use the Melcloud app to change settings. I am at the moment trying to get to grips with the FTC6 control unit, which is in the most useless place it could be, in a tight-ish narrow cupboard which is where the cylinder is. See photo. Before anybody comments on the location of the cyylinder…Yes it is not ideal, it is in the coal shed, but I have insulated the door now, and the location is surrounded on the three other sides by rooms in the house.

I have got as far as checking what the Summary of Settings is, and I have manually altered the Legionella settings slightly so that it runs during my off peak hours.

I am running the ASHP 24/7, not on timed settings (obviously at the moment it is idle a lot of the time). Operation Mode is room temperature rather than flow temp or Weather Comp. I have it set at 17 on the room thermostat (1 zone only, 8 big rads, have thermostats all set the same at 3). This is a bungalow.

At the moment the outside temperature is 18-20 degrees during the day, so the heating isn’t kicking in much, and in the evenings I nudge it up by a degree at most if I need to. When I do that, the heat is delivered pretty quickly even though the rads never get more than vaguely lukewarm.  Then down to 17 overnight. The living room has a thermometer and it reaches the set temperature plus some. The other rooms seem to be evenly heated also. But I haven’t measured that. And the house doesn’t smell damp anymore..,,Overnight we are still getting frost, but it is taking the cylinder about 15 hours to drop from about 50 to 42 at which point the DHW kicks in. 

I have different priorities from people who previously had access to the gas grid. I am delighted with this system so far and will not be dissatisfied if in winter it continues to deliver an internal temp of 18 even using 60kwh a day, maybe even more, which some people are distressed about,  I wanted a heating system that would be more efficient and future proof. The whole system plus cavity wall insulation has been paid for and installed on local government and Home Energy Scotland grants, therefore has cost me nothing. I previously had old storage heaters. We do not have access to gas in the village, which is in the Cairngorms. Only electricity. So for ten years my bills have been humungous, usage up to 60kWh a day from Nov through to April, 30 kWh a day in Summer. 14000 kWh per annum on average.  For not much heat at all. But at the moment, my total usage per day is 6-10kWh. So I am in a different situation from all these people who were using gas boilers in bigger houses with internal temperatures of 21/22. I do not want my house to be at those sweltering temperatures, in Winter I will be looking to have 18-19 degrees internal temperature. I will supplement the ASHP if necessary

with my log burner. All my calculations of running costs are based on worst case scenarios where the tariffs are higher than now and the ASHP uses at least what my old heaters were using. 

It is an Ecodan WM 85VAA. At the moment it is not set for weather compensation but I will be wanting to do that in winter. Heat Geek says, the best time to set that up is when it’s cold. It is currently operating in Normal mode. Most of the settings are the default settings except for Legionella and Freeze stat.

Because it is an FTC6 controller the Energy Usage report is only indicative, but it tallies with what I am seeing on my meter, and I am monitoring usage daily. 

My big concern is the Freeze Stat Setting - the minimum setting is for it to kick in at 3 degrees but in winter we can have up to 20 days in December where the temperature is freezing and there is snow lying. A neighbour had hers deactivated and it was much cheaper to run after that, but of course this means that you are dependent on the anti-freeze being sufficient to prevent freezing, Mine is currently deactivated. 

@juliamc  thanks, yes, I have them all set at 3 at the moment, rather than some at closed and some open. Incidentally, it isn’t water whizzing around them apparently. It’s glycol?

@M.isterW Many thanks for your explanations - very useful to have some indication that the auto adapt setting is efficient, although I am not yet up to speed with the proper names for these settings, I know that it is not running in Weather Comp. mode. I do have a single wall mounted thermostat in the hall and the hall radiator has no thermostat.. The hall is small so I am considering having all the doors open even though that goes against the grain…..

The guys who set this system up were singularly uncommunicative. They left me with a bunch of Mitsubishi manuals but no contact number (!) and just a lightning speed explanation of the hall thermostat. Everything I have found out I have found from this forum, from youtube and from googling. It is a steep learning curve! 

My original question was about the settings on the FTC6 on the 2nd page of the Summary of Settings (see photo) - can anybody tell me what the settings on the right hand side refer to in plain English - ie Hflow2 CRoom1 20C Cflow1 15C? 

And, should I have the Freeze stat on but set to the minimum setting of 3 at which temperature it will be coming on all the time in winter -

or have it deactivated and rely on there being the correct amount of antifreeze/glycol? in the system?

What a relief to find your posts!!!

I am on day 5 of going through exactly the same process of learning the ropes.  

I was told not to read the instruction manual as I would need a PhD to understand it. This advice was not wrong!

I'm googling, researching, contacting people and I STILL can't get the answer to how to get the blasted heating to obey the timer schedule I've put in.  Something, possibly to do with hw2 flow, which is why I've ended up here.

I'm thinking of retraining as a heating engineer..…

Keep going. If I can , you can and we'll beat the system together.

Meanwhile, after two more hours of stress research, I am going to get Christmas organised.  It'll be considerably easier. Not something I ever thought I'd say!

Regards

Vicki

@juliamc  you asked for a photo of the pump (“Hiroheater” apologies to Hirohito….) in the snow. Here it is. Note the unfinished snow shelter….I have a low concentration span…..it will be finished in summer 😂 We have about 6” at the moment (I clear the front if the pump every day)  and still falling. In November we had a week of -11C or more , consumption increased to about 30kwh but still only half what my storage heaters used to use. At the moment it is minus something all the time and Hiro is doing just fine, under 30kwh a day, with the room temp set at 19C 24/7. Hope it isn’t snowing where you are as you guys down in Blighty don’t do snow very well…..

@juliamc the side panels are palettes so they aren’t solid and the air can flow. I would have the temperature at 20 for preference at the moment, but I am determined to keep the cost down. It has cost me just over half as much as the storage heaters used to cost, so far. For some weird reason, other people in the village who have exactly the same set up, same installers, same sort of house, are paying twice as much and saying that these pumps don’t work well here. Which suggests that the only variable, THEM, is responsible for their costs. I think they are trying to operate them as gas boilers. I am more and more convinced that timed settings are not cost effective. BTW I couldn’t live in 22C….I would melt!

Heat Geek has a youtube video where he tests out an air source pump in an enclosed space. I am intending to put a roof on my “shelter” - it will be about a metre and a half above the pump - the whole purpose of it is to stop the tons of snow that falls off the roof falling onto the pump. I have a snow guard on the roof above it also. I clear the snow in front of it every day because I imagine it doesn’t do it much good to be surrounded by its own supercooled air.

I sent a pic of our DHW to cylinder to world heat cylinders and they told me to change all the pipe lagging to Armacell lagging also using with Insulated tape. Cylinder is in the loft and they said it may as well be outside as the loft in winter is freezing,,so treat it as outdoor. Told us to insulate every single pipe coming out of it, even if its void & not used, as we’ll be losing heat out of it. So weve done all that, installers had used standard lagging..not for freezing outdoor temps..Can anyone tell me how they use auto adaptive mode, where does it take the temps from. Ive been using W/C...i dont have wifi room stats just the FTC controller pad that I assume has  a stat in. I put it in ‘room stat’ mode thinking it would use the curve settings, but its not, flow is like 48,,,my curve is set at 35/-5 and 25/15…. house is redders! but ive read ppl using AA mode as its cheaper, what do I need to do this/try this? Comp Curve in winter is using 60kWH in 24 hrs...monthly bill for |Dec 23-Jan 24 was £374. 17 rads in bungalow, standard insulation.

@Jenp Without the WiFi controller I’m fairly sure it’ll use the stat in the main controller. Where is yours situated?
Wherever it is that temp will be used as the indoor temp, which is shown on the controller screen…  @amanda1 and @M.isterW have the WiFi controller and are using AA

I’m experimenting at the moment with a setback of just 1 degree from 9pm to 6am. The heat loss continues day and night of course, and usually the temp difference is greater at night so more heat loss then, and that’s when I get the cheaper electricity.

Usage pattern isn’t really relevant, the effect of people being in the house will add heat, opening doors will move heat around or lose it if an external door, but the hp will just tick over more efficiently if it’s left at a steady target temp.

@Jenp just lost an entire reply so here goes again: 

1. Get a wireless remote thermostat see photo.
2. Do not demand instant water heating via the melcloud app or the thermosat - this relies on the immersion heater. If you have it set to auto adapt (ie Room Temperature control) then it will heat the water when the water temp drops below a certain minimum. In my case it heats the water every 15 hours or so. 
3. Use auto adapt and get used to the idea of the pump running when it chooses, not when you choose it to.
4. Do not use timed settings. It is not a gas boiler. 
5. I have stopped using any degree of set back at the moment and the house is warmer as a result and the usage is about 20kwh a day for the whole house, not just the pump but the oven, tv etc etc as well. My Wireless Remote Controller is set to 19. Temps here in the Cairngorms lie between -18C and 5C or so in Dec through to February. We have had a couple of weeks of -10C or less and max total electricity consumption was 38Kwh. 
6. Expect the pump to cycle on and off every two hours or so on the coldest days.
7. Make sure your system has glycol in it and turn off the Freeze Stat function. 
8. Don’t demand tropical temperatures from it when it is minus C outside. These pumps struggle most around the 0 degrees C mark, and the hotter you want your house the more it’s going to cost you.

My ASHP is on auto adapt, my room temperature setting is 19C, my DHW is 50C with a max drop of 10 degrees before re-heating, my Dec to Jan bill was £200 with a standard variable Economy 10 tariff from OVO, but my bills in Dec-Jan before getting the Pump (ie with storage heaters) were £350 a month. The ASHP has nearly halved my annual electricity costs.

I also came across some stats from a research project in Norway, where they use ASHPs a lot, that suggested that having the DHW desired temperature at 35 or 40 meant that the COP of the pump increased in colder weather.

The more I read in these forums and on FB from local folks who have Heat Pumps, the more I suspect that people are trying to use their ASHPs as if they were gas boilers. I also think that installers don’t explain that if you want to “advance” the heating of the water, then it will be the immersion heater that does the heating, and this costs ££££. If you have your water on timed settings, and it drops low in temp during the off period, the ASHP prioritizes DHW heating and it will spend an hour or more getting the water back up to temp before it starts to heat your house. If your heating is also on timed settings, then your house will maybe take more than an hour after that, to get up to temperature. If you want it to be 23C in there, then it will definitely cost you!

Get a wireless thermostat, use Auto Adapt / Room Temperature Control, and let the pump do its own thing. Keep the wireless thermostat in a room that is reasonably central, and not drafty.