Octopus Heat Pumps

stripling

@Spies

Don't tell me this... 🙉
Yet another example of erratic 🐙 
I'm paying nearly £500 to buy a new rad and for my local plumber to sort mine out.  🙈

matt_drummer

Spies said:

Interesting you say they don't quote for bathrooms as they are replacing my radiator in there without being prompted? 

They did for mine too. It has to be at 23c, an MCS requirement.

It was one of two radiators I had to change.

As we all know, I had to change them all in the end to make it work, Octopus and 50c flow temperature is a disaster!

matt_drummer

stripling said:

matt_drummer said:

I think I know where the £500 quote comes from.

When mine was first installed they were offering installations at £3,000 which is the same as £500 now that the grant has increased from £5,000 to £7,500.

If your heat loss is less than 7kW they can install a 7kW Daikin. This is an old heat pump that uses R410a refrigerant.

I suspect they still have a stock of them they want to move.

I am pretty confident that they don't install any Daikin R32 Monobloc heat pumps for £500

Here 'tis: 

stripling said:

matt_drummer said:

I think I know where the £500 quote comes from.

When mine was first installed they were offering installations at £3,000 which is the same as £500 now that the grant has increased from £5,000 to £7,500.

If your heat loss is less than 7kW they can install a 7kW Daikin. This is an old heat pump that uses R410a refrigerant.

I suspect they still have a stock of them they want to move.

I am pretty confident that they don't install any Daikin R32 Monobloc heat pumps for £500

Here 'tis: 

Yep, and for that I think you'll get an obsolete 7kW Daikin heat pump running on R410a refrigerant.

matt_drummer

MP1995 said:

matt_drummer said:

MP1995 said:

So this is the same person that kicks octopus on various threads despite being a previous pioneer tracker v1 customer like ourselves (we have saved thousands of pounds) and is now kicking them once again over their heat pump quote.

A bit like wrf you realky can't please some people, everyone is out to do them on money and making too much off them.

My inkling, after watching some YouTube quite and install and from the posts here and other forums is that Octopus were initially making a loss on installs, getting up to speed. Now they are breaking even and into small profit.

Octopus are really good at installing heat pumps at a really good price. They do a great job, as good as anybody.

They are rubbish at system design and have no idea how the heat pumps they install work in real life.

It's a problem.

All my opinion, of course.

I was hoping the team up with heat geeks might lead to some lower flow temp designed systems....hoped....and not just the use of the heat geek "supposedly designed" kitchen cupboard hot water store.

I beat most Heat Geek installations with my cheap Daikin installed by Octopus. You don't need heat geeks, you need big emitters, proper monitoring and the tenacity to use the data to sort it out.

I don't have the time or the inclination to explain what is wrong with the `heat pump combi'

Suffice to say, I am not a fan. 

The correct flow temperature, flow rate and dT are the keys to making a heat pump work, there's nothing else to it. My heat pump is the same as any other 8kW Daikin, all that matters is what it is connected to and how you use it.

stripling

matt_drummer said:

If your heat loss is really 5.6kW then I would insist on the 8kW heat pump.

At the flow temperature you will need to run I think you will struggle to get enough out of the 6kW because of defrosting.

Basically, I think you'll be cold.

The 8kW will be no less efficient than the 4 or 6 as they are the same.

I guess you got 4,931W from your Octopus radiator schedule?

If so, you won't even be able to get the full output of the 6kW heat pump at the design temperature which I would assume is something like 20c indoors at -2.3c outside?

It will never do it based on my experience, it will be defrosting so much at times that you'll be luck to see about 4kW of heat.

Yes, I got the 4,931w from the schedule. Plus the radiator I'm having installed by my plumber in my bathroom. 

What's the defrosting like? When does it kick in temperature wise? How long does it take? 
I deliberately chose a part of the wall that gets a lot of sun for the heat pump so I hope that helps? What do you think? 

There's no way they will fit an 8kw - the office-based design team wanted to install a 4kw but I showed them the pre-Octopus gas use plus the install lead backed me too. Also, I'd had borescope images of the cavity walls that showed gaps in the insulation. (Hopefully the guarantee will sort that eventually)

I know (from your OEM threads) the software limiting on the 3 Daikin models but I have the data sheets from the EU installer's portal that shows that all the three smaller models 4/6/8kw achieve higher outputs than their badged kw number. I'll try and upload an image if I can. 


 

stripling

Daikin 6kw Data sheet: 

Spies

I've seen 6kw daikin units on heatpumpmonitor.org punching above their weight, my heatloss is 5.5kw (dt50/-2), the emitters total 6.4kw, I'm not too concerned and if it doesn't work, octopus will be coming back to make it work.

Glad its being installed in October as it shouldn't take too long to show whether or not its working correctly.

stripling

This is the 6Kw data sheet @40º C

matt_drummer

You only have to look at the DHW performance to see that they are all the same.

The 4kW models heat water just the same as my 8kW. Have a look on heatpumpmonitor.org, they put out just as much heat when heating DHW, they are just limited in heating mode by software.

I and many others know that they are just software limited.

You gain nothing from the `smaller' ones other than cost.

My 9kW spent about 18 minutes an hour defrosting when conditions were prime for this.

My 8kW has only defrosted once and that was in the first couple of days until I changed settings, but I can run at 30c flow at 0c outside.

At 33c flow my 9kW was much better and defrosted less often.

At 42c with my original radiators it was 23 minutes heating and then 10 minutes defrosting.

It could never get to 50c, I tried.

Your radiator output is tiny, about 20% of mine.

You won't like me saying it but I predict a problem, sorry.

stripling

Spies said:

I've seen 6kw daikin units on heatpumpmonitor.org punching above their weight, my heatloss is 5.5kw (dt50/-2), the emitters total 6.4kw, I'm not too concerned and if it doesn't work, octopus will be coming back to make it work.

Glad its being installed in October as it shouldn't take too long to show whether or not its working correctly.

Yes, see the data sheet I have just posted from the EU installer's portal. It's very useful you can play with different configurations.  And yes, that's one reason that I stuck with them - the lead installer I met was great. As I said earlier in this thread they have a good reputation for putting things right.  

I'll be stalking you for feedback if you get yours in before me.  😁