Gary68

Yep that makes sense, the controller just isn't set up for 2 zones, you could just put both sets of wires in IN1 if they can fit. Your very welcome

Are you seeing 2 zones on the controller per my earlier image Are you seeing 2 zones on the main controller now? If not SW2-7 may need to be moved to on and maybe SW3-6 as well the manual isn't the clearest. Don't forget to power it down before any changes otherwise they won't take effect

I'm no expert but if your heat pump is set to a single zone I don't think IN6 will be doing anything as it has be to enabled for 2 zones, if you turn off the thermostats that are linked to the UH8 that is wired to IN1 and leave the thermostats wired to IN6 still calling for heat does the heat pump continue to run?

They need to be on IN-1 for single zone operation, that's where my UH8 is wired to, so Lr and Ls need to go to IN-1

Is the FTC set up for 2 zones, do you have an upstairs that is a separate zone, if the dip switches are set for 2 zones you should see the 1 and 2 under the heat pump symbol. You could wire the 2 manifolds as separate zones, I would have thought you could wire them to the same zone in parallel, its just a signal for the heat pump to start up, it won't care where that signal is coming from.

The water temp is set to 50C but is it actually getting to 50C? How long are you heating the water for, mine is set to 48C and takes an hour to heat back up after normal use from completely cold it takes just under 2 hours. Do you have the Melcloud app for your ecodan that shows hot water temp here is mine from last night, showing it reaching 48C.

Are you sure you are pressing and holding the menu button until the menus come up, its a press and hold to get to the settings a quick press doesn't get you there its at 2.28 in the video

Video on how to set your hot water temp.

Here is a video on how to set the weather comp curve.

Auto adapt uses your weather comp curve so it needs to be setup for your house, if 45C worked for you when it was coldest you have one end of the curve you just need to set the other end and see how it goes

If you can see the thermometers and water drop next to the flow temp on your controller screen then you are running at a fixed flow temp, yours should look like this we 45C if you are running at a fixed flow of 45C If you can see a graph curve next to the +/-0C then you are running in weather compensation If you can see a house with a thermometer in it next to what is the set room temp then that is auto adapt mode.

Yes it does but it won't show you COP it will show you the flow temperatures you are running though hour by hour for the past 24 hours. Is there a reason you are running at 45C constantly, you need to turn on auto adapt and set your weather compensation curve up to get the best COP at milder temperatures.

The plots are from the Mitsubishi web library, they are for an 8.5kw unit so not the same as yours and they are the COPs at an operating temps of 45C (not 35C) which is what you said you were running your unit at. The lines are at ambient temps of 15, 7, 2 and -7C The COP's are only a guide you can't take them at face value they are at laboratory test conditions but you should get in the same ball park which you are. These are the charts for the 12KW unit the first is at 35C the 2nd 45C so at 2C the 2nd bottom line you should be getting between 3-3.5 depending on whether you are running at 35 or 45C which is what you are getting

You haven't stated what size Ecodan unit you have but your COP's look pretty spot on to me at 45C. The 2nd bottom line on the plot on the right is COP at 45C when its 2C outside which is probably about right for Jan on average, so you should get a COP of 3 at 45C which is exactly what you are getting.

Quoting cost isn't useful, much better to quote usage in kwh, £300 a month at 30p per unit is 33kwh per day, that is relatively normal for a heat pump in the depths of winter. My house has used 950kwh in Jan so far that's 40kwh a day, 30kwh of that will be the heat pump. So depending on location, outside temp, heat loss of house, size of house etc, her usage may be correct.

The RHI just states it has to be the main source of heating and/or DHW, I'm not aware of anything that says you cant use a woodburner to supplement if you need to. I had PV before I had an ASHP which I get RHI for and had more added afterwards, RHI doesn't cover PV at all it covers solar thermal, and you could have solar thermal and an ASHP as the same time and get RHI for both.

From the figures you have posted the heat pump is working fine you have a good DT of 5 and the flow rate is more than adequate, it does sound like its simply down to the flow through the radiators which should be easily remedied. Good luck

Do you have the Melcloud app so you can see the flow and return temperatures by hour? If not, go to the service menu on the controller and go to thermistor readings and post a screenshot this is will till you the flow and return temp of the heat pump circuit. Whilst you are there go into running information and type in 540 this will give you the flow rate of the heat pump in litres per minute. If its not bad balancing of your rads and the heat pump is struggling to get up to the required temperature it could be due to low flow rate.

I trialed Homely a couple of years ago when they were trying to get going, then it was working with the Octopus Agile tariff but simply increased heating during lower price periods. It did use weather forecast and learnt how fast your house heated up but it didn't work well in my average 2006 built house, with different temp requirements upstairs and down. I only tried it as they were giving it away and there was no subscription fees. Now its expensive and there is an additional subscription for the 'smart' features I think its improved since I was using it, as its now adjusting WC but its really a system for people who have no interest in tweaking their WC, fit it and it will work out of the box at a cost, with limitations others have said as really needs a well insulated house that is all one zone. I see a better application for it as an installer tool. You leave it running for a few months over autumn/winter, it determines your WC curve, your installer comes back programs it for you and removes the device.

If you are getting a Mitsubishi Ecodan, make sure you get the Melcloud wireless add on. With this you can set the heat pump to use different modes (fixed temp or weather comp). So in the IO period you can run a hotter fixed temp and slightly over heat the house and then run weather comp during the day in the more expensive period. I would look at other makes of heat pump, its sounds like your property doesn't need a lot of heat and Mitsi's don't modulate down to low power will Daikin for example are much better at that.

In this cold snap mine defrosts every 50-80 mins depending on flow temp, I run at 45C overnight in offpeak period and last night at -2C it was defrosting every 50 mins, currently its still -2C, flow temp is 35C and that reduces defrosts to every 80 mins. With the shorter time between defrosts I do wonder if there is any heat benefit from running at the high flow temp as it has to recover more often so the average temp may not but much different.

Hi welcome. Apologies for the brief response but some starters for 10. 1 You need an MCS registered installer to be eligible for BUS so can't just use anyone in the trade. 2 That will be part of the assessment prior to installation if they are large you should be ok 3 You need an EPC that is less than 10 years old, if its got recommendations for loft or cavity wall insulation then that may need to be addressed You have to remove the old boiler and the ASHP has to be used for Hot water and heating, heating only is not allowed

I trialed Homely on our Ecodan a few years ago, it was ok, but limited due to the integration with the Ecodan it could only use the smart grid connections to boost the room temp by 2 degrees in cheap periods it couldn't modulate flow temp, so great in theory not so much in practice and the temp nodes kept losing connection to the hub which was an issue. Now that it can modulate flow temp its probably a much better offering but at £200 and a subscription to get the best out of it, i'm not sure its going to get much traction. As @JohnMo suggested as an installer tool I can see the value in that in setting an initial curve for a customer rather than setting too high so you don't get a call back.

You haven't heated the water for long enough overnight, it was set to 50C but you only achieved 40C in the 1 hour schedule, increase the schedule to 2 hours so it can get to 50C then you may have enough to last all day, I assume you are heating overnight as you are on an off peak rate, if so, don't be stingy with the schedule, if its has to reheat during the day its going to cost a lot more.

We have a 250L tank its on a schedule for heating up overnight to 48C for 90 minutes, its typically finished in an hour. Then there is no hot water schedule till the following night, there is enough hot water for 2 showers, kids full bath and washing up with plenty to spare. You could also try lowering the temp a degree at a time see if anyone complains, I have found 48C is hot enough for a adequately warm shower in the morning and the water is still more than hot enough for the kids bath 12 hours later. Ignore what the tank temp says on the controller when the kids have their bath its says its 30C and after I have filled the bath it says it 18C, its just the position of the sensor in the tank.