It's probably worth adding that it's unlikely that Samsung would offer a thermostat to go with their heat pump because you shouldn't be using a thermostat to control a heat pump!

It's also probably worth adding that homely wont/can't (I presume) stop the heat pump cycling when the demand is less than the minimum the heat pump can turn down to.  It may however 'manage' the cycling intelligently into the longest cycle time possible without causing your house temperature to swing too much.

Ps I agree with all the recent comments by @derek-m and @toodles.  You don't need a homely, you almost certainly don't need to change your thermostat.  What you need to do is adjust the WC curve to do the job and get your thermostat out of the way of the control loop by turning it up above the target temperature and using it purely as a limiter.  The main advantage by far of a homely is that it essentially does the WC adjustment for you, but that doesn't make it necessary

@toodles @jamesPa

Two degrees UP!

Adjusting the Thermostat such that it is two or three degrees above my need does go against  my grain.

It feels like waste ,......................  a waste of a £120 Honeywell Home!

Are you buying homely soon?

@iantelescope This is the whole point Ian, the WC makes the necessary adjustments - and does them far more kindly than any thermostat ever could. It won’t make a difference whether you set that ‘stat’ 2 degrees or 3 degrees higher than comfort temperature - the WC is keeping the house at the right temperature - regardless of the ‘stat. Regards, Toodles.

@iantelescope I have homely - and think very highly of it too! Toodles.

@toodles 

Homely advice ?

Did you , yourself, or a "Trained Installer" install  your Homely?

Why are so enthusiastic about it ?

What are the pros and cons ?

My instincts , are still bi-metal strip , but , I can still understand and appreciate Weather Compensation.

Disabling a £120 Thermostat still feels like waste!

@iantelescope The ASHP installers fitted the Homely controller for me. Why the enthusiasm? Well, I required a system that I could set and forget, I wanted a system that would be as efficient as possible, I wanted a system that could be used by my wife were I ill or I kick the bucket, I wanted to be sure that whatever the weather, I could rely on the system to keep us warm - at the lowest running cost.I believe that we have achieved this with Homely and their technical support is excellent as I have confirmed each time I have contacted them.

I suspect their insistence on trained installers fitting the Homely is to ensure it is done properly. The training is not that involved; it is mainly an online training video and the company encourage fitters to ring them when carrying out their first installation and will ‘hand hold’ them through anything the fitter needs to know to ensure success.

I have the bonus of access to the installer’s ‘Connect’ app so I can check performance parameters as the whim takes me. Am I impressed? Yes! Can’t think of any negative aspects, other than it is not free!

Regards, Toodles.

Posted by: @iantelescope

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But, What if If I want to best use Octopus "Cosy" , what then , How?

I would just leave it to run on WC, treat the cheap periods as a bonus and the expensive one as a kicker.

Cosy is really for people with a battery, due to expensive period at tea time to 7pm.

I'm on E7 and will be leaving mine to run the whole 17 hrs of expensive time, aided by a battery.

Posted by: @iantelescope

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My instincts , are still bi-metal strip , but , I can still understand and appreciate Weather Compensation.

Don't, just don't.  The only sane way to run a heat pump is to use weather compensation and that's a direct consequence of the laws of thermodynamics so you aren't going to circumvent it (there is of course an exception, if you are running at a very low design flow temp, say sub 30C, then there may be a case for fixed flow temp in some circumstances).  If you let a thermostat control it you will cost more, quite possibly a lot more, and be less comfortable. 

Posted by: @iantelescope

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Disabling a £120 Thermostat still feels like waste!

It should never have been fitted in the first place, but you need to get over that.  As a temperature controller it is fundamentally unfit for purpose, as is absolutely any thermostat. 

Use it as a limiter and if you need a time switch.  Or remove it, replace it with a wire/reconfigure the heat pump to ignore it, and sell it, just don't use it as a temperature controller!  And if you do replace it with a 'simple', even bimetal, thermostat you still need to set that 2-3 degrees above the desired temperature so it acts as a limiter not a controller.

@jamespa 

Believe it or not ...........................I totally agree with you.

I have been using the Samsung Weather compensation offset Screen for most of the last two years.

I use, and intellectually understand, .......................but I, and quite a few others , do not like!

Sorry, .............for my senior moment !

Posted by: @iantelescope

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I use, and intellectually understand, .......................but I, and quite a few others , do not like!

I guess that's where homely comes in.  @toodles has summarised why he has it.

Unfortunately the Samsung heat pump controller lacks (or did lack - it may have changed since I studied their manual) auto adaption.  Thus it relies on the installer or homeowner to set up WC correctly.  The first is challenging to say the least  unless the installer revisits during the season, which few will.  The second is very unlikely with the average homeowner.  Basically its a 'fail' in most of real world, which is probably why homely saw Samsung as one of several good targets.  Maybe Samsung's principal market has different user/installer characteristics.

@jamespa 

A comment by a visiting French Samsung Engineer that " he did not understand many parts of the Samsung Manual " does not inspire confidence.

No "installer " has , in my experience , inspired any confidence in their opinion of themselves, their company or in their  non-existent training.

With "installers" and manufacturers staff so poorly trained , who is to be trusted?

@jamesPa  many thanks for your obviously competent and experienced  advice . Appreciated!

Posted by: @jamespa

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Posted by: @iantelescope

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I use, and intellectually understand, .......................but I, and quite a few others , do not like!

I guess that's where homely comes in.  @toodles has summarised why he has it.

Unfortunately the Samsung heat pump controller lacks (or did lack - it may have changed since I studied their manual) auto adaption.  Thus it relies on the installer or homeowner to set up WC correctly.  The first is challenging to say the least  unless the installer revisits during the season, which few will.  The second is very unlikely with the average homeowner.  Basically its a 'fail' in most of real world, which is probably why homely saw Samsung as one of several good targets.  Maybe Samsung's principal market has different user/installer characteristics.

I think that balancing the heat emitters is probably more difficult than setting the WC curve, the important aspect is not to try to rush either.

As a starting point, the warmer weather end of the WC curve could be set for a LWT of 25C at an OAT of 20C, then dependent upon the heat loss calculation data, the cold weather end could be set at something like 45C at an OAT of -5C.

The above should provide a reasonable IAT, which should then be monitored for a period of time. If the IAT is deemed to be too high, then lower the 45C value slightly and monitor again. Repeat the process over days, or even weeks, until you are happy with the results.