My experience with 3 heat pump surveys: Heat Geek, British Gas & Octopus
We’re really excited to be recording a landmark Homeowners’ Q&A podcast next week:
“UK Heat Pump Heavyweights: British Gas vs Octopus Energy vs Heat Geek vs Aira vs EDF.”
We’ll be unpacking what sets these major players apart, from their installation models and consumer protections to how each maintains quality, consistency and trust at scale.
Our goal is simple: to help homeowners cut through the noise and understand where true value, reliability and long-term performance really lie.
Got a question you’d like us to ask the panel?
Drop it as a reply below, DM or email me directly at editor@renewableheatinghub.co.uk… we’ll try to include as many as we can.
Get a copy of The Ultimate Guide to Heat Pumps
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@editor Here are my suggested questions:
- In your designs, how do you trade off the up-front cost of the system versus ongoing running costs?
- What level of efficiency (seasonal coefficient of performance - SCOP) do you design for?
- Do you offer performance guarantees - e.g. the room temperature that can be achieved, SCOP, annual heating bills? What recompense does the customer have, if your system doesn't meet those guarantees?
- Under what circumstances do you recommend buffer tanks or low loss headers? Do you warn customers that they will lower the efficiency of their systems?
Grant Aerona 290 15.5kW, Grant Smart Controller, 2 x 200l cylinders, hot water plate heat exchanger, Single zone open loop system with TRVs for bedrooms & one sunny living room, Weather compensation with set back by room thermostat based load compensation
@grahamf good set of questions. Can I suggest just one minor refinement to Q1:
- In your designs, how do you trade off the up-front cost of the system versus ongoing running costs? Do you offer customers a choice of these trade offs?
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.
I wanted to provide an update in regards to the insulation visit today, which may prove relevant to heat loss assessments.
He used cameras to look inside the walls and a large thermal camera to look around the property, frankly it was scary. My property is a 2004 one, however he told me that he recently did an assessment on a new built, that had the same issues as mine, with the new owners making a claim on their NHBC to get the insulation up to spec.
In my case there are huge gaps where there is no insulation between the walls, so I have cavity wall insulation randomly placed around the walls, I would estimate only around 50% coverage. In addition there are section where I could see pretty much blue on the camera. Same for the loft insulation, made it look like it was covering the loft, but with large gaps where it wouldn't be picked up.
I strongly believe that the UK has serious issues rolling out heat pumps. I don't think our houses are actually fit for them and the first step for home owners is to insulate the property as much as they can. In my case, I think I am looking at £5000+ costs.
Posted by: @dreiI wanted to provide an update in regards to the insulation visit today, which may prove relevant to heat loss assessments.
He used cameras to look inside the walls and a large thermal camera to look around the property, frankly it was scary. My property is a 2004 one, however he told me that he recently did an assessment on a new built, that had the same issues as mine, with the new owners making a claim on their NHBC to get the insulation up to spec.
In my case there are huge gaps where there is no insulation between the walls, so I have cavity wall insulation randomly placed around the walls, I would estimate only around 50% coverage. In addition there are section where I could see pretty much blue on the camera. Same for the loft insulation, made it look like it was covering the loft, but with large gaps where it wouldn't be picked up.
I strongly believe that the UK has serious issues rolling out heat pumps. I don't think our houses are actually fit for them and the first step for home owners is to insulate the property as much as they can. In my case, I think I am looking at £5000+ costs.
Yes but...
The evidence is that many heat loss surveys overestimate the loss quite significantly, and there are relatively few reports of heat loss surveys that underestimate loss. Your house may well be an exception, of which there will of course be many in absolute terms but likely a very small percentage. What do we do, deconstruct every house? I dont think so.
Unfortunately we have to deal with a legacy of dodgy builders going back centuries and as we know dodgy builders are still out there. Thats the real world and, given that its been like that for centuries it would be an extreme optimist that thinks this may change.
We could of course conduct heat loss measurements on homes, in fact I have been advocating for over a year and a half that we do just that in the most cost effective way possible ie by using consumption as a sanity check. Sadly few people in the industry want to hear this, because it disturbs the certainty (that they cant be blamed) that the fabric GIGO spreadsheet gives them. And sadly few outside the industry have thought about it enough to care.
The fact is that we have to deal with the world as it is, not some idealised world that we would all love to live in. The world as it is contains buildings that catch fire, fall down, aren't insulated in the way that they should be, have the wrong materials installed, get damp when they shouldn't and many other horrors. So shall we stop doing anything until all that is fixed?
We need to face the fact that a proportion of the construction industry is basically sh1t, always has been and almost certainly always will be. Then we need to deal with that whilst not paralysing ourselves. Difficult I know, but how it is.
Of course I wish it were otherwise and I am sure you do to.!
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.
It would explain the difference between different heat loss assessments, so the person doing it, will most likely be either accurate enough, or overestimate, which seems to be the case, better safe than sorry.
I think my heat loss assessment was pretty accurate too, taken in consideration the current insulation state. I couldn't really see any heat escaping through the outside walls, but did see some dark areas inside the house, I am not sure if it was anything to worry about. My main issue is the loft, and is something I will need to get on straight away. A few rolls of insulating loft wool should do.
When insulating lofts, how do you cover spot lights? Is there something I can put around them or just leave enough space? I was thinking like making some kind of protective shield out of mesh, so the insulation won't fall or get pushed on it. Being LEDs, they shouldn't get that hot. I think quite a bit of heat is escaping around the spot lights, maybe there is some sort of rubber seal that you can put around them.
Posted by: @dreiWhen insulating lofts, how do you cover spot lights?
try these
Mitsubishi Zubadan 14kW with Mixergy 210l DHW in 220m2 barn property. 24 solar panels = 9kWp with GivEnergy 5.0kW Hybrid inverter and 19kWh GivE batteries. Jaga Strada fan-assisted rads throughout. Landvac vacuum glazing/triple glazed windows.
Posted by: @dreiIt would explain the difference between different heat loss assessments, so the person doing it, will most likely be either accurate enough, or overestimate, which seems to be the case, better safe than sorry.
Very definitely.
I think the market has changed a bit since mine were first done now nearly three years ago. There are clearly loads of installers out there who still religiously use the default assumptions, dialled into opaque tools, which can lead to large overestimates that have a material effect on the design - eg 16kW 'surveyed' vs 7kW actual in my case. The same installers will often refuse to account for invisible fabric upgrades, like IWI for example. There is also another class of installers who use experience more, often with much simpler (and thus much more transparent and if necessary flexible) spreadsheets/tools, to arrive at figures which are usually more realistic, but much more dependent on installer skill. The most recent podcast about the heat geek 'zero disrupt' offer refers to this obliquely but quite extensively.
The two which I eventually shortlisted for my install fell firmly into the latter category. Simple tools (bordering on crude) combined with experience and (hopefully) bolstered by my own consumption data, leading them to propose 7kW designs rather than 'safe' (for them not the customer) 16kW designs. Perhaps they have made mistakes along the way, but have learned from them.
I can accept installers making mistakes, we all do from time to time and we all have to start somewhere with our learning processes. What I cant accept is installers who ignore solid evidence that what they are proposing is wrong or who, having made mistakes, resist fixing them!
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.
- 26 Forums
- 2,289 Topics
- 51.4 K Posts
- 288 Online
- 5,949 Members
Join Us!
Podcast Picks
Latest Posts
-
RE: Renewables & Heat Pumps in the News
I thought an aircon doubling as a heat pump could do ou...
By Batpred , 29 minutes ago
-
British Gas vs Octopus Energy vs Heat Geek vs EDF vs Aira
This week we brought together five of the biggest names...
By Mars , 31 minutes ago
-
RE: Here is my heat pump installation with questionable COP in Italy
By materox345 , 35 minutes ago
-
RE: Heat Pumps Without Grants: Would You Have Installed One & Will You Now?
Agree, "inflation" is high on ASHP installations. We...
By Batpred , 2 hours ago
-
RE: New Fogstar 15.5kWh upright solution
Just wanted to share some info for anyone facing challe...
By Batpred , 2 hours ago
-
Daikin Altherma HT Temperature Sensor Question - Caution: Mentions AI...
Hi All - first post for a while, hope you are all well,...
By Marzipan71 , 3 hours ago
-
RE: DHW heat loss through pumps.
Which is exactly how houses used to be designed (and I ...
By JamesPa , 3 hours ago
-
RE: Octopus Cosy Heat Pump Owners & Discussion Thread
I think I have plenty of system volume in the radiators...
By AndrewJ , 3 hours ago
-
RE: Do Heat Pumps need to start up at Full Power?
@steelbadger We have an LLH with secondary pump; the se...
By Toodles , 6 hours ago
-
RE: Electricity price predictions
We live in a democracy on a crowded island so everyone ...
By JamesPa , 6 hours ago
-
RE: Grant 13kW Aerona3 - issues getting zones to temp
And the saga continues… So today a Senior Grant Engin...
By Crimson , 21 hours ago
-
RE: Installer Fitted 9kW Instead of 11kW Heat Pump and Changed MCS Paperwork - What do I do?
@jamespa Yes, the OAT sensor is situated on the back pa...
By Toodles , 23 hours ago
-
RE: Ecodan ASHP Low COP and Unstable Compressor Frequency
Just to clarify, returning water from UFH is colder tha...
By lukewarmbath , 23 hours ago
-
RE: 10kw heat pump run in 24*7 data?
A different heat pump (Midea 14kW) but a stark reminder...
By cathodeRay , 23 hours ago
-
From what I see, the work to upgrade the cable, etc all...
By Batpred , 24 hours ago
-
RE: Confusion over Octopus Tariffs
That's sounds great. I have no ASHP, but 15kwh storage....
By Batpred , 1 day ago
-
RE: Solis S6-EH1P8K-L-PLUS – Why I Chose It and What I’ve Learned So Far
Locked environments are difficult to manage, it also me...
By Batpred , 1 day ago
-
RE: Has anyone seen this problem before? Huge anticycling times
Hi all, I had a 15kw installed 3 weeks ago. The past we...
By jamesh , 1 day ago
-
Adia Therma - 'autopilot for heat pumps'
Thought I'd pop this one in here as the Adia proposal a...
By seatonian , 2 days ago



