@dandee 😀 

Installation was ok.

It was the commissioning that was terrible!

Seems to be the norm. Decent install on the wet side with monobloc and rads. Usual mediocrity with the rest:

Condensate drainage overlooked, check.

climate compensation overlooked, check.

Control using a naff HIVE 3rd party on/off t/stat to cycle the ASHP 6 times an hour and burn through double the electricity,  check.

Little or no proper commissioning & home occupier handover, check.

My experience was the same. I reached out to the installer ‘Thrift Energy’ and the equipment supplier & commissioner ‘Grant U.K.’ to suggest ways they could both improve the level of customer service and efficiency of new installs. Still waiting to hear back from either of them. 😉 Once they’ve got your money they’re not remotely bothered if the system as left by them is operating grossly inefficiently and costing a fortune to run.

Symptomatic of an industry that needs a good regulatory kick up the arse. OEMs and installers should be contractually obliged to realise the MCS SCOP & COP performance estimate with a clawback clause on any shortfall recoverable from the install cost. Then they would start raising their game.

I’m abandoning my attempt to get a heat pump for the time being. Until I can find a local company I can trust with a good record of successful installations I’ll stick with gas, solar, EV and a battery. There seem to be too many issues as @AllyFish mentions above still to resolve.  

@davesoa don’t blame you.

we don’t have gas and were about to need a new boiler and a new oil tank so went the ASHP route.

it’s a massive fail by the powers that be - the tech can work well for many but as per this thread there’s lots that can be done wrong. Simply offering a £5k grant as uk does now just compounds the issue - a HP is not a straightforward replacement for a combi boiler. Unrealistic expectations and poorly conceived financial incentives is not a good combination.

 @allyfish is right re incentivising/penalising long term performance.

my two cents.

I won't be having a heat pump installed, because I can't get anyone to give me a sensible quote, despite having at least ten companies visit.   But I will be installing a heat pump myself because that appears to be the only way to get what you want. Fortunately I have a degree in physics so understand these things, can do the calculations myself, and if necessary am  prepared to experiment a bit.  I've been watching thus forum and buildhub for over a year, so have learnt plenty from that.  Many won't be this fortunate or willing to experiment.

My conclusions about the (installation) industry, doubtless with some exceptions, is that its full of fly-by-night companies exploiting the grant who appear to be bound by (or use as an excuse) a set of inflexible rules that inhibit innovation, fail to deliver quality in too many cases, make end-user prices unaffordable.  Most real plumbers can't be bothered, because it's too much hassle and they have plenty of work anyway.  

To fix it the following is required as a starting point IMHO

Scrap mcs as a condition for permitted development, retaining only the noise condition not the rest, freeing up the option for straightforward non-mcs installations.

Develop engineering options which do not compel the customer to replace the dhw cylinder, so the user has the option to avoid most of the cost and all of the disruption this entails (two quite simple options have been discussed on buildhub, either of which could be made to work and one of which is already part of the offering by mixergy - but sadly limited to their cylinders)

Undertake an education programme so the homeowners understand the differences (from a user perspective) and why these matter.

Incentivise regular plumbers to engage (this needs careful design/thought)

Remove the crazy mcs restriction that design and installation must be contracted with the same company, allow customers to commission designs separately and/or simply specify what they want.

Make supply of ashp equipment zero rated, not just supply and install

Either scrap mcs altogether(probably the only realistic option), or develop competition.

and of course

Fix up the, in large part artificial,  price incentive to use gas rather than electricity.

If at least most of these changes were made (many of which amount to opening up a currently closed-shop market, which should be popular with the current set if politicians), many of the conditions inhibiting adoption would fall away or reduce.   That alone would not guarantee take up, some more work needs to be done on pricing (eg put a carbon tariff on gas boiler's and use it to subsidise ashps).  

This won't stop rogue installers, but by opening up and enlarging the market it will dilute them.  Established plumbers, who at present are all to often not bothering with this sector, value their reputation so will want to do a good job.  

There’s a lot of sense in what you say. I’ve now had to go down the Section 75 Consumer Credit route over my failed installation. Having decided to stay with gas until I can find a reputable local installer with an impeccable record (they don’t currently exist) I asked my plumber to look at part converting our heating system to be heat pump ready. With the questions he asked about the planned/failed install I realise how much questionable work had been intended. I’m not technically minded, struggle to put a light bulb in without instructions (but I do know the law). It might all have come good at the end but the episode has made me very wary of using anyone without a solid track record. 

@davesoa Sorry to hear that experience.  Although it's undoubtedly useful I tend to treat with a healthy scepticism criticisms by one tradesman of the work another has done.  Many have 'their way' of doing things, which often is no better than someone else's.

There is a lot of BS in the heat pump industry, often from people who should know better, about what is 'necessary' to make heat pumps work, much of which does not stand up to analysis.  Unfortunately this all to often becomes a 'must do' as far as an installer is concerned, to cover their rear ends.   It's the same with many electricians, who all too frequently say that upgrades are 'necessary' when in fact they aren't.  When the BS merchants are challenged they become defensive, angry or say that it's too complex to understand.

I would be interested to hear what your plumber thinks is necessary to make the system 'heat pump ready'.  Of course, whether a change makes sense does depend on the specifics and what you are anyway doing for other reasons.  The risk you run, unless you are doing the work anyway, is that when you do eventually have a HP installed the installer has a different view!

To be accurate it’s me that’s saying let’s make it heat pump ready(ish) not the plumber who I’ve used for 30 years but your point is well made. 
Questionable decisions include.

• No description of where the pressure escape valve (if that’s the correct description ) for the unvented hot water cylinder would run.  
• No description of the necessity (or who will do it and pay) to move 6 sockets to make way for the bigger radiators. 
• One room needs a further radiator. My plumber wondered just how that was going to be achieved given the current pipe run. 
• The need to replace the current heated bath towel rails. 
• I have a Powerwall. The wiring needs to be completed by a Tesla authorised electrician in order to ensure the warranty is not invalidated. I’m not sure that had been picked up. 

And so on. 

As a number of my radiators are 30 years old, my power shower pump has failed again and the head of water is poor I thought the installation of an unvented hot water tank and fitting of new radiators that meet heat pump standards might be a Good Thing. 

@davesoa

You could always start with improving insulation if that is possible.

@davesoa all very fair, I'm not questioning your plumber, just being cautious.

Just one warning about the UVC.  Heat pump cylinders have much larger coils than most normal DHW cylinders (vented or invented) -  3sq m vs 0.8 sq m. If you are having a UVC installed now then make sure it has the larger coil (which will make it physically slightly bigger for any given volume of stored water).  The coil size difference matters, and not just because of reheat time.  Currently there is no productized work around* (although one would be possible) so many installers will insist on ripping out a perfectly good UVC and replacing it with a new one if the original does not have a large enough coil.

(*exception - Mixergy do sell a work around for their own, rather special, cylinders.)

There is also an argument that a dhw tank for a hp should be larger to store more water at a lower temp.  This depends on usage though.

It's probably worth adding that many HP installers seem to insist you need 28 mm hw feeds to the UVC when fed by a hp.  This is usually BS, 22mm, the norm, is good for 6kW (arguably 9kW) under typical hp operating conditions, the equivalent of 2 standard immersion heaters.  So unless your reheat requirement is particularly fast, that should be enough.  This doesn't necessarily hold (although it may well do) however if your HP is larger than about 12kW.  Doubtless each installer will have their, often immovable, opinion notwithstanding the science.   Also many installers will want to use the hp manufacturers pre plumbed cylinder, it makes their job easier and means they can use rookie plumbers whilst still standing a reasonable chance of connecting it up properly.  In this case 28mm feeds are most probably required, depending on ho size, length of run etc.

The other one I've heard is that the CW to the DHW tank feed needs to be 22mm not 15mm.  Many UVC manufacturers 'recommend' this, but I can't fathom why it would be necessary if your mains pressure is reasonable.  This, however, is not a heat pump specific thing so your plumber will be able to answer the question for your house whether or not he knows about heat pumps.

Apologies if you already knew all or any of the above.

@davesoa all of those are good things to get done prior to changing the source to a heat pump, and I did a number of those things myself prior to doing exactly that.   In some cases actually myself (radiators) in other cases using a local plumber (for the UVC, as you need a specific qualification to do that, not DIY'able legally). The fact that your guy is asking about where does the "escape pipe" go suggests he is qualified. using your local plumber to do them may well be cheaper (based on labour rate) vs an "ASHP company".  And a local electrician for the sockets , same thing. 

even if you don't change the heat source it will make things more comfortable - with bigger rads you can run the boiler at a lower temperature, which "feels" nicer , and with an UVC (providing you have good mains water pressure) you can get better showers, and this all reduces what you have to ask an "ASHP" supplier/installer to do.

the only bummer you don't save the VAT. but that may be compensated by reduced labour rates. if you firm up on this with your local plumber please feel free to post specifics on here for review.

Thanks @JamesPa and @iancalderbank for those great suggestions. I’ll post back when my plumber and I have agreed what to do.