I don’t know enough about it, but I was speaking to a ‘premier’ installer earlier this year who mentioned that installations under ECO 4 in Suffolk were extremely cheap and, therefore, poor, with subpar equipment being used. I’m not sure if this affected the choice of heat pump brands. I’ll ask around and post more concrete findings when I have them.

Our system was fitted a year ago under ECO4.

It is working well.

I have learned through posts here that some small things could have been done better, mainly external pipe insulation in a few places. The Gen6 handover could have been better BUT I have learned for myself because of that.

I guess the main potential downside in my case was the use of multiple sub contractors. The plumber who installed the heat pump is local (20 miles) so that is OK but the overall system was fitted in separate chunks ..............

Roof insulation.

Ventilation units/window vents.

Internal wall insulation.

New radiators.

Heat pump, tanks/controls etc.

Solar panels.

.......... over a period of 6 weeks last spring. We weren't left without services in between so it was OK.

I was given a proper survey and all the work was done to the normal specifications. 

As for choice ? I knew what I was getting from the start. I pushed for more panels and different tanks,controls, pump location and a two zone system (son is in an adapted extension and has no body temp control due to his condition so I wanted to keep the ability to have the extension separate). So, some choice.

I suspect I may have been lucky and can see that an install under the scheme COULD be a bit fraught.

It's a mixed bag it seems. Not necessarily in terms of the actual kit installed which for ASHPs at least appears to be all the usual brands but there's quite a lot of criticism of installation quality. 

I don't think there's any 'choice' of which ASHP but there isn't much choice with some big name installers either. Every installer will have their 'brand' they've got deals with. 

I would say depending on whether you have to use the installer list from the local council or not, google the names like crazy and apply to multiple companies. Some installers are fine but they're also booked up. Researching company names on Trustpilot and asking in forums etc is probably a good idea. 

We have just had our property updated on the ECO4 scheme, so I will share our experience here for others.

Firstly, there are literally dozens of companies doing ECO4 work. You don't have to go with the first company you contact. We initially thought we would need to find a local company, but that is not the case. Most companies work nationally and will take on work anywhere.

In our experience and due to the nature of the works, a common business model is that the companies offering the ECO4 scheme tend to subcontract out the different elements of the scheme. Many of the websites you see advertising on facebook are either coordinators or just introduce you to a coordinator, no doubt for a fee / slice of the deal.

We had surveys from around 6 different companies, each offering different types of Internal wall insulation, ASHP systems and solar installation. Each company offered to "coordinate" the works (and grant applications) whilst sub-contracting out the 3 main areas of work.

By the time we were on to our 3rd or 4th company (some rejected the project once they saw what was involved - seems some just want the quick easy wins), we had a reasonably clear idea of what we wanted in terms of the IWI system used and ASHP installation. The solar aspects were all remarkably similar with just the basic PV array and basic 3kW solar inverter (no option for hybrid/batteries on ECO4).

All of the companies we had surveys with use one brand of heat pump - one used Midea, one Grant and the company we used supplied Samsung. There was no choice within what the company would supply, so it was important to select a company whose offering fitted well with what we wanted. Each company seems to offer a fixed setup that they are familiar with.

I think we probably got lucky too - other than the fact they insisted on an over-sized ASHP (a common complaint, but they have to stick with their MCS heat loss calculations) - we have been really pleased with the works conducted. The IWI team were brilliant - they have fitted PIR backed plasterboard to all external walls and re-plastered throughout. They also insulated and plastered a vaulted ceiling that previously had no insulation. The ASHP team were again brilliant - they have fitted a 12kW Samsung ASHP and pre-plumbed DHW cylinder from Joule. They ripped out all our existing plastic micro-bore piping, and re-plumbed everything in 22mm copper, down to 15mm copper at the radiators. All radiators were upgraded to the largest sizes possible, so meet the design criteria for flow temps of 40C at ambient -2C. Some companies were suggesting my microbore piping might be OK, others said they used plastic. There were areas the plumbers could easily have cut corners, but they went the extra distance to make sure we had decent pipe runs in the heating system.

Our solar installation was relatively straight forward - no issues with our roof, so 9 x 405W panels, south facing and unshaded with a 3kW basic inverter.

I've no idea of the overall cost of the works we've had done, but it was certainly substantial. I took the view that even if they made a real hash of it, I could probably get a plumber in to come sort it out for £2-3k and still have benefited from works costing at least 10 times that. I could probably buy an 8kW Samsung unit (more appropriately sized for my property) for not much over £2k and do a straight swap if the oversized unit bothers me that much and sell my 12kW unit on ebay.

My advice would be to first do your research and know what you want - what is important to you. Must you have a Valliant ASHP, is all new copper piping important or are you happy with your existing pipework, need new/larger radiators? Then have surveys from many different companies, and ask questions of them to determine which offer best aligns with what you want.

Two of our neighbours have also just had similar works completed on ECO4. One is very pleased with the works conducted (I've seen the works and they look to have been completed to a high standard), whilst the other was less impressed.

There is no doubt the works are completed to a price point - Samsung heat pumps seem to be at the lower end of the price range looking on some vendor websites. Elsewhere though, I saw little evidence of cost cutting. The IWI product used was top quality, and upwards of £85/sheet (and they used a lot of it!). The Joule pre-plumbed cylinder solution is what it is - no doubt saves the installers time and standardises installations. There were no corners cut in completely replacing the radiators with all new Stelrad radiators and copper pipework throughout. They could have tried to cut costs by sticking with commonly sized radiators (e.g, 1600x600) that are cheaper per m2, but they went with less common (and more expensive) sizes to ensure our emitter output was maximised within each room's space constraints to minimise the required flow temps at design temp.

Let me know if you have any specific questions - happy to answer if I can.

Thanks for all the information everyone. Very useful and I will pass it on 😁