Posted by: @ksim

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for example Gemini calculates that the flow should be fine, but still scared of microbore so recommends buffer tank.

That’s a very interesting exercise…. And it’s good to see some caveats in what was offered. I think Gemini is cautious of microbore for good reason since there are too many unknowns.

Apart from specific bore size…. How was it installed eg with kinks and tight bends? How many radiators are Daisy chained off a 10mm branch pipe? Is there any push-fit plastic microbore. To name a few.

We do have some microbore and it does work but we did do some remedial work to ensure the pipe sizes cascaded down so that only 1 radiator was fed from one branch of 10mm pipework. There is a limit as to how much heat energy a 10mm pipe can carry. The attached file shows how much energy can be carried by a given pipe size.

ps adding a buffer tank doesn’t solve the problem of under sized heat carrying pipes for a given load requirement. 

Posted by: @sunandair

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Apart from specific bore size…. How was it installed eg with kinks and tight bends? How many radiators are Daisy chained off a 10mm branch pipe? Is there any push-fit plastic microbore. To name a few.

this is why I provided current flow temperatures in the prompt and dt at different pump speeds and asked to do calculation of the existing flow. LLMs are not "thinking", looks like Gemini training data is more incline to install buffer or separation for microbore. so even the flow is fine, it recommends a buffer. 

I do not exclude any problems with microbore, absolutely possible to have an install where a buffer is needed, or repipe. I had installers from: "microbore won't work", "microbore will work but with only with lowloss header", to "everything is fine it will work if you keep it as open loop and weather comp", Let me show an example of my data and you can decide for yourself.

This is 5 hours of tonight, outside temps are 1-2C (external sensor). boiler minimum delivery is 7000kW, so every interval is boiler running at that power.

Room temperatures over the same time

7000W at delta T 5K, you can calculate the flow, there is a formula; similar to my heat loss/size/design temperature properties are running at ~12l/min according to heatpumpmonitor.org.

Running a bit further, I've asked Gemini to calculate the heat loss, gave property build/extension walls/roof insulation, windows, etc, no sizes except the whole house, it estimated 5.3-5.8kW, ChatGPT - 3.3kW, Heat Geek - 5.3kW. Next I provided annual gas consumption, ChatGPT run out of calculation tokens so I dropped it, Gemini adjusted to 2.0 - 3.0kW for the main house and 600W for the extension where Air2Air currently used. Next provided graphs from above and final recommendations were:

Please do not think I am trusting LLMs here, it is just interesting.... 

It would be interesting to feed to LLMs some real data which requires separation, if I increase flow temp from my boiler in the prompt they immediately starts to have doubts that ASHP will work in the property and recommends to keep gas.

As an idea, load a design document  from the installer to LLM with all the numbers and ask to analyse it for possible questions to the installer and problems system might have. 

 

I have watched with interest the youtube videos on Heat Geeks ZDHPI and the concept seems very good. A friend of mine has just had an ECO4 house upgrade but unfortunately they insisted on putting in a gas combi boiler. He has just fitted the house throughout with under floor heating and wants to upgrade to a heat pump.

Ahha I thought ZDHPI will be perfect, since his heat loss is 6kW and all that is required is a swap out of the combi and install of the heat pump and cylinder, he might even get it for less than the grant!

He contacted a local HG installer WDS Green Energy and their estimate without radiator changes was ..... (have a guess before scrolling down :-))

 

 

 

 

 

 

 

 

 

 

£6368 on top of the £7500 grant!

Pricing the kit they have quoted for thats approximately £8000 labour 

He is situated in Neath, Wales so if anyone knows any sensible installers in the area please let me know.

@bontwoody, this is really interesting, because I’m hearing very similar things from both installers and homeowners at the moment.

There’s a growing consensus that the Heat Geek Zero Disrupt model may have been positioned as a way for installers to get a foot in the door where they were previously struggling to win work.

What I’m seeing more of this year are reports of very high quotes (the kind of numbers you’d normally associate with a full system overhaul) but in reality they’re only covering the heat pump and basic materials, with no cylinder upgrades or emitter work included, not dissimilar to your example.

I was actually on the phone earlier today with a well-known installer who said he’s seen a sharp increase in install costs from competitors in his area and not just from Heat Geek-affiliated installers.

It’s perplexing that this is happening IMO.

 

@editor Its difficult to fathom, I was putting it down to a niche market with few competitors in Wales. I have actually fired off an email to HG in my ire, so I will report back if I hear anything (or not)

@bontwoody would love to hear the feedback and justification from Heat Geek on this one. When you break your example down, just fitting the heat pump (no rads or cylinders) is a two day job, max. That price tag is crazy. 

I posted my own example a while back on a tiny bungalow and it was estimated at £10k with no other upgrades, which was crazy.

@editor He would need a cylinder but the HP and cylinder would be £5000 to buy on the open market without the trade discount. I can see us fitting it ourselves if nothing changes. It just smacks of greed from the installer.

Here is HG's response:

Hope you're well and thank you for raising your concerns.

Firstly, it's really great to hear you're a fan of us at Heat Geek and recommended us to a friend! We appreciate the support from the community, as word-of-mouth from people who understand the Heat Geek philosophy is how we grow.

Secondly, and on to the point of the quotation- we can't accurately confirm if this is a result of the inflated costs or the works that need undertaking without knowing the property name and customer details. It is, however, important to clarify how our pricing and the Zero Disrupt (ZD) model work in practice to ensure expectations align with the reality of these installations. While recent Zero Disrupt installations are averaging around £11,000 total (approximately £3,500 after the Boiler Upgrade Scheme grant), the full range typically sits between £7,500 and £20,000. A quote of £6,368 on top of the grant (roughly £13,800 total) is higher than the average, but it still falls well within our expected pricing bracket for a high-quality, guaranteed installation.

If your friend would like us to take a closer look at the specifics of the proposal to ensure the design is as optimised as possible, we would be happy to review it. Please ask them to contact the Upgrades Team directly with their quote reference or property details, and we can walk them through the logic behind the pricing.

Honestly, with the exception of fitting a cylinder too, I cant think how this installation could be any easier. My friend is getting the company to come in and give a revised quote. Lets see.

Posted by: @bontwoody

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Honestly, with the exception of fitting a cylinder too, I cant think how this installation could be any easier. My friend is getting the company to come in and give a revised quote. Lets see.

My HG non ZD quote was £15000, ZD done few month later £14700, both didn't include any rads/pipes updates, both included new cylinder 170/200L, as I was coming from combi, not much changed 5kW Vaillant from non ZD was upgraded to 7kW; real property heat loss is 3kW (at -3C) so ZD overestimated heat loss even more, "complicated pipe routes" was given as the reason for "higher than avg cost", and yes pipes go through extension extra 5 meters. Went with another installer £10k all in, 5kW Ebac with 300L cylinder, job took 2 days for 2 plumbers, and 2 sparkies for 6 hours on the second day, So far very happy, used 169kWh in March of electricity for heating (4 bed 1960 semi 108m2) and hot water. I am lucky to have eon Next Drive for now with 6.7p/kWh.

 

Posted by: @bontwoody

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and all that is required is a swap out of the combi and install of the heat pump and cylinder

Isn't that the crux of the matter? Swapping a Combi for a cylinder may require a complete replumb of much of the hot water pipework - depending on where the cylinder will be located relative to where the boiler was. 

In my case, a HG ZD install came out at to about £5k (after the grant). No radiator upgrades, same cylinder reused, but about 25m of new primary pipework across the attic, down the outside wall, bridged over a path - and digging a soakaway for the defrost drain, and 'upgrading' the old vented heating primary circuit to unvented. It was really quite a bit of work and took two guys about a week, plus an electrician for a day.

We’ve taken a deeper look at the recent investment by Carrier Global Corporation into Heat Geek and went directly to Aadil Qureshi to understand what it actually means for homeowners.

The headline is simple: in the short term, nothing changes. But scratch beneath the surface, and this raises bigger questions about control, accountability and the growing role of platforms in shaping how heat pumps are designed and delivered. If the industry is moving towards more integrated ecosystems, homeowners need to understand what that means, both in terms of quality and risk.

Full piece here: https://renewableheatinghub.co.uk/the-battle-for-control-of-the-uk-heat-pump-market-has-begun

Posted by: @bontwoody

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@editor He would need a cylinder but the HP and cylinder would be £5000 to buy on the open market without the trade discount. I can see us fitting it ourselves if nothing changes. It just smacks of greed from the installer.

We are in the process of getting some initial estimates for a replacement of a combi with an ASHP. The plan would be for the HW cylinder to go where the boiler is, so reducing pipework changes. Our electrics are ready. We will probably just need a 6Kw unit. 
I am however getting very high estimates from EDF and local installers, up to like £12k on top on BUS. 😜 
It is making me wonder if this is just not the time to get into it...
Could the quotes come down from the clouds into reasonable territory after a survey? 
Not long ago, @bash and others managed to get their ASHP systems for £3-4k after BUS, which is roughly what we would be paying for a replacement of our combi with a similar reliable gas boiler brand. 🤨