Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
British Gas versus Octopus: Two possible heat pump routes - how to evaluate them?
@johnmo
If you compared to a 45 design at -7 you are taking a 20% increase in heating costs, if you are forced to flow at 55. @ivanopinion
The object of the exercise for me is to negotiate my way around the 50º design temp through the back door, so to speak. Despite still seeing other 🐙 customers getting 45º design temps my lot won't (or I suspect, can't) budge.
So..... I've been attempting to negotiate slightly bigger radiators to give me a wee bit more room for manoeuvre after the install is done and dusted - I'm hoping for no more than 40º flow temps, preferably less.
I'm shoe-string productions right now - I can't afford to buy new rads. My install team aren't daft, they know perfectly well what I'm doing and so far have played along.
But the -1.3 thing is just an expression of my irritation with a) tick boxes of any sort; b) unreal tick boxes that bear no relation to the reality of the location. 🤷🏻♀️
I disagree it is unlikely. It all depends. 15% is the difference between 5.8kw and 6.7kw, so maybe a 7kw machine would be OK for both levels of heat loss and a 6kw would be too low for both. But 15% is also the difference between 6.5kw and 7.5kw, so a 7kw machine might be OK for one but for the other you'd need the next size up. Which would be overpowered for the vast majority of the year.The jump in heat demand from -1.3 to -7 is about 15% so unlikely to make the next sized heat pump a requirement.Posted by: @Anonymous
If you compared to a 45 design at -7 you are taking a 20% increase in heating costs, if you are forced to flow at 55.Posted by: @Anonymous
For a handful of days per year.
@lucia This technique worked for me; the installers were, as they all seem to be, designing for 50 degrees and I requested and had fitted radiators that provide our very comfortable 22.5 degrees around the whole house and 25/26 degrees in the bathroom at ~35-45 degrees LWT when the temperature is minus 2 or 3 degrees. We are very pleased that I percy veered on this and although our installers were possibly not the best ever team who have worked in our house but at least, they demonstrated a degree of ‘flexibility’ for our installation. I suspect that they would normally treat their average customer as less well informed and remarked to me that they rarely came across customers who knew just what they wanted! Regards, Toodles.
Toodles, heats his home with cold draughts and cooks food with magnets.
Sounds like Outfox the Octopus. 😊 . Which is my plan when/if they give me a proposal.
Daikin 6Kw ASHP.
MG4 EV, Solis 8KW inverter, 32KWh battery
1926 Semi with loft and wall cavity insulation, all radiator.
@ivanopinion you must of spent ages come up with some vague numbers like that. You didn't even allow for DHW heating
@lucia I got my Octopus contract wohoo! Guess the design temp? yup 50 C. However I am generally pleased at first sight but will be checking over the weekend to try to see how it would be at 45 C . I think the ground floor is OK but I may upgrade some bedroom rads myself. The odd one is they want to change my recently fitted 600 by 600 K2 with one of a lower output. So I'll either let them do it and keep the one they remove or keep the new one.
Daikin 6Kw ASHP.
MG4 EV, Solis 8KW inverter, 32KWh battery
1926 Semi with loft and wall cavity insulation, all radiator.
Posted by: @luciaThey want to change a rad for lower output? No way, that's nuts.
Problem best dealt with onsite imho. The onsite plumber will almost certainly be happy to leave you the new rad and knock off an hour early.
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
@lucia the surveyor did mention the Kraken software glitch which he said he would correct. However there will be two other rads in that room and the difference is small. Still a free rad I can use elsewhere. The referral sounds good but sure where I enter it? I am getting a free service to compensate for the long delay.
Daikin 6Kw ASHP.
MG4 EV, Solis 8KW inverter, 32KWh battery
1926 Semi with loft and wall cavity insulation, all radiator.
@jamespa Agreed and I have made the site for the pump easier for them to install.
Daikin 6Kw ASHP.
MG4 EV, Solis 8KW inverter, 32KWh battery
1926 Semi with loft and wall cavity insulation, all radiator.
Posted by: @jancold@lucia the surveyor did mention the Kraken software glitch which he said he would correct. However there will be two other rads in that room and the difference is small. Still a free rad I can use elsewhere. The referral sounds good but sure where I enter it? I am getting a free service to compensate for the long delay.
What Kraken software glitch? 🙈
If you can do your own rad changes there's no worry - me, I've yet to attempt any plumbing at that level, kitchen tap changes are the extent of my expertise. 😁
As for the the referral - you could add it when you sign your contract I guess? They add them to your energy account I believe - so you could use it for the service contract I guess? Or energy bills? Or maybe it won't work - but here: Octopus referral code: 4593442
My installation starts in a week - give thanks, I'm done with boiling saucepans for hot water and no heat. 🥶
@lucia Thanks for the referral I'll put it in my mail to Brad before signing the contract.
Stu , my surveyor said Kraken sometimes replaces radiators with ones of less output which has to be manually corrected, either he forgot or the monster overruled.
Boiling saucepans, no fun! hopefully our boiler will go on till the installation date.
Daikin 6Kw ASHP.
MG4 EV, Solis 8KW inverter, 32KWh battery
1926 Semi with loft and wall cavity insulation, all radiator.
-
Heat pump done right first time? Installation in Kent.
3 weeks ago
-
Daikin 6kw setup with Dixell controller
2 months ago
-
Daikin Octopus installation update - I saw my first defrost. 😍😂
6 months ago
-
Are Octopuses Slowing Consumer Adoption of Heat Pumps?
7 months ago
-
Vaillant arotherm plus heat pump frost protection
1 year ago
- 26 Forums
- 2,590 Topics
- 60.3 K Posts
- 522 Online
- 6,922 Members
Join Us!
Worth Watching
Latest Posts
-
RE: Air-to-air heat pumps - best models and installers
@ashp-bobba, do I remember correctly that you install A...
By Mars , 7 hours ago
-
RE: A2A vs A2W: Which Heat Pump Would You Pick?
There isn’t as far as I know, @djh, but you’re welcome ...
By Majordennisbloodnok , 11 hours ago
-
RE: Can anyone explain the following behaviour with a Grant Aerona 3 R30 / Smart Controller?
Final Update. Yesterday, I was going through the moti...
By Unsure , 13 hours ago
-
RE: How much can an east/west solar solar system be oversized?
Best performance occurs with PV string near inverter no...
By bobflux , 13 hours ago
-
RE: Forum updates, announcements & issues
Thank you Mars for all your dedication to improvements;...
By Toodles , 16 hours ago
-
RE: Who do I complain to about a poor ECO4 installation, can anyone advise?
Take it one step at a time. If you can get the dhw and...
By JamesPa , 22 hours ago
-
RE: Selling 2 x Kensa Shoebox 7kw GSHP (New)
Hi Jain, we’ve got an ashp so I’m afraid we won’t be yo...
By Judith , 22 hours ago
-
No buffer or low loss header Grant controller in sens...
By JamesPa , 1 day ago
-
RE: Are We Sleepwalking Into Another Race to the Bottom?
That's an amazing job to get all that in there! A truly...
By Batpred , 1 day ago
-
RE: Anyone concerned about GivEnergy?
Thanks for your advice - I'll keep trying with the inst...
By JohnDwyer , 2 days ago
-
RE: Plug and play solar. Thoughts?
I am also yet to find a case where an installation that...
By Batpred , 2 days ago
-
RE: British Gas vs Octopus Energy vs Heat Geek vs EDF vs Aira vs OVO vs EON.Next vs Boxt
This is what I got from OVO. At least it was quick.. ...
By Batpred , 2 days ago
-
RE: IVT greenline HT Plus E - Circulation Pump Constantly On
Welcome to the forums. Irrespective of which brand yo...
By Mars , 2 days ago
-
RE: 7.5kW Heat Loss, But Quoted a 10kW Midea. No Re-Pipe, No Buffer Tank. Does This Add Up?
Oh, how I love these old scientists!I'm in with your 5 ...
By LeJamaisContent , 2 days ago
-
RE: Jokes and fun posts about heat pumps and renewables
@jamespa Someone who is not easily phased I suppose.
By Toodles , 3 days ago
-
@downfield Once OE had removed our gas meter and capped...
By Toodles , 3 days ago
-
Living with a Low Loss Header (Or Measure For Measure, it’s All About the Pump)
I know, low loss headers (LLHs) aren’t necessarily ‘low...
By Toodles , 3 days ago
-
RE: What is the main ‘dictator’ of Agile’s unit price?
After seeing umpteen negative price slots again today, ...
By ChandyKris , 3 days ago
-
RE: The Reality Behind a Failed Heat Pump Installation – and an IWA Insurance Rejection
@ian-w Getting back to the problem in hand, what do yo...
By JamesPa , 3 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@papahuhu Generally, I leave Homely to take care of mat...
By Toodles , 3 days ago
-
@judith, glad you found the story interesting. On eff...
By Mars , 4 days ago
-
RE: New Vaillant aroTherm Plus in black - When will it come to the UK?
The vaillant controller and app do all of that (and mor...
By JamesPa , 4 days ago


