@hr_3 

Hi Hr_3,

I would suggest that you read the manual and see if your ASHP is capable of operating in weather compensation mode. If so, it would probably be more efficient to use this mode, since it should automatically adjust the water flow temperature rather than you have to keep changing it manually.

I'm not sure if this has been posted but it's quite a good analysis of heat pump performance, if you like this sort of thing.  

Quick query 

Trvs on radiators should I leave them on 5 or turn down relevant to what we like the temp at?

We are finding if we set thermostat at 18.5 say, heating will go up to 19.5 before it turns off

@hr_3 depends on the rooms. 5 everywhere and then adjust the bedrooms as needed.

Posted by: @batalto

@hr_3 depends on the rooms. 5 everywhere and then adjust the bedrooms as needed.

that's what we do.

@derek-m My big question of the day 🙂

Normally, my ASHP spends most of its time turned off. Naturally, this is nice and cheap...

For the past few days, my ASHP has not turned off at all. Oddly enough, in comparison, this is ruinously expensive...

OK, I know that it has been rather chilly of late. My average temp outside for the past day has been -1.5°C as opposed to +10°C 10 days ago, but is there any way that I can calm it down a bit, so it doesn't run all the time?

TBH, further to these thoughts, a few hours ago I tweaked my Weather Compensation Curve. I moved my old 0°C setting down to -4°C to see what happens. To my mind, the absolute worst that can happen is an earful from the missus, if it unexpectedly gets a bit Baltic indoors.

@justinsb 

Hi Justin,

I'm afraid it is all down to that old saying 'there is no such thing as a free lunch'.

Unfortunately, ASHP's suffer from a slight problem, in that they are very efficient in the Summer months when you don't require them, but not so efficient in the Winter months when you do.

As I have stated before, the efficiency of ASHP's reduces quite dramatically with falling ambient air temperature.

In a reply to Kev yesterday, I pointed out several ways in which it may be possible to reduce overall energy consumption, the most effective of which being to reduce the indoor air temperature setting. This I see that you have done.

I'm afraid it is now a balancing act, between what is comfortable physically, and what is comfortable financially.

@justinsb 

Justin,

Are you running the ASHP constantly in both of these scenarios and letting weather comp control things? If so and it's like mine, in your top (cheap) chart the ASHP will be cycling on and off at its lowest output (so lots of off time) and in the bottom (ruinously expensive) one it's on all the time. If you move the setting down enough it will start cycling again but as you say, you risk the house (and maybe your relationship with your other half) cooling.   

What I'm going to try next is to turn the heating off using the Ecodan timer for  5-6 hours overnight.  Because I have radiators the house heats up quite fast so I'm hoping it warms up by waking up time and doesn't use too much energy doing so.  We'll see. 

@kev-m yes, I thought about trying that way too, but until they fix my Energy Monitoring electricity meters, I can't see what's happening.

Yes, it's "on" all the time, with the Compensation Curve running things. The changes that I made to my Curve have apparently stopped it from running all the time, which currently seems good. However, I might have pushed it too far the other way, so I will have to closely monitor how warm the house actually feels. At the moment, my outside temp has raced up from -3.3°C to +1.5°C, so it's hard to tell if I have made any progress or not, but it's not running, which is probably good.

I do feel there is a level of "its cold outside chaps" in this. The heating is going to be on and its going to be running a lot. ITS COLD. 

Looking at my own figures, yesterday to deliver the same heating from gas I would have spent £12.94 - I spent £13.35 with the ASHP. However the day before it would have cost me £12 with gas and I spent £11.35. using £0.0588/kw with gas and £0.15/kw with electricity.

Over the days I have figures I would have spent £133 on gas and I spent £125 with the ASHP. These are flat calculations as well, ignoring the cheap 5p rate I get for 4 hours a night.

My point is just that its the winter, its going to be cold, we should expect bigger bills - however we pay virtually nothing over the summer months. You can't have it both ways

Posted by: @batalto

My point is just that its the winter, its going to be cold, we should expect bigger bills - however we pay virtually nothing over the summer months. You can't have it both ways

Very true, but gas users would pay virtually nothing over the summer as well.

It's not a benefit of ASHP's that heating is cheap over the winter, it's a benefit of there being warmer weather in summer.

If the ASHP is more expensive to run than gas, then people will (rightly) think something is wrong. And it's not necessarily the ASHP that is the problem then - it's that gas is much cheaper per unit than electricity as it is heavily subsidised. 

@batalto, yup, I agree.

My problem was that my ASHP had passed an arbitrary limit that I personally had set on it. It meant that instead of cycling on & off, whilst still keeping the house toasty warm, if flicked everything over to maximum overdrive. This kept the house slightly warmer than it has been recently, but had the downside of also turning the money tap onto maximum overdrive along with the ASHP. What I hope to accomplish is to convince my ASHP that it can go back to cycling on & off, all the way down to -4°C, as opposed to stopping at 0°C. If the missus doesn't turn into an ice maiden, I'm going to try reducing the flow temp too, just to see what that does to my system...