ProDave

I dislike the hidden agenda behind smart meters, but in this context I was just pointing out one of the "benefits" that you get to see high usage immediately so in this case this might be why so many are raising this issue at the moment. Yes I know that. That is why it annoys me when some installer has installed an ASHP in a sub optimal manner and given bad advice, resulting in higher running costs than if it had been installed better, and worse when they "sell" the system as being cheaper to run than the old heating system. And it annoys me when in some cases even recently built developer houses have cut corners are are still being built a lot worse than they need to be. There is also a lot of ignorance among the public, on another forum I was reading of someone that just bought a house with an ASHP and because of that, he expected low heating costs. When questioned a bit more, it was an old stone house with an EPC E. It should have been obvious that with such a poor EPC any heating system is going to use a lot of energy.

I would still give in to the inevitable. It is going to happen, so negotiate and make it happen on favourable terms to you.

I blame the smart meter. Years ago nobody would know it was using a lot for a few cold days, they might read the meter once a month, or very rarely and a few days high usage would just get lost. Now so many people have a smart meter's in home display cheerily telling them how much they use hour by hour, they start to panic.

I am surprised it carries on running having failed to defrost. That makes me thing it does not even know it needs to defrost? Sensor failure or miss placed?

A solution looking for a problem? What is wrong with an ASHP on the ground where you can service and maintain it? Do you really want to get the scaffold out each time it goes wrong? This test house they are building, it looks to be inside a commercial unit. How is that going to work? or is it a massive environmental chamber where they can simulate all sorts of different weather?

And there in a nutshell is half the problem. One lot says "you must do this" and the other lot says "oh no you can't"

Yes but the OP has a less than 1 year old new build. We would hope that is built better, but perhaps that is another can of worms?

Do let us know what they say. I am a big fan of ASHP's used correctly but deeply sceptical about the plans to replace most gas boilers with an ASHP as I fear the vast majority are going to end up like this performing badly, and the resulting bad press will have everyone claiming ASHP's are rubbish.

Refreshing to hear. Ours too is working well. It shows that properly designed they do perform well and in cold weather. Sadly the forum is seeing a lot of threads about ASHP's behaving badly in the current weather.

The screws won't make the VCL like a sieve as the screw will remain filling the hole. If a screw does miss the joist, leave it in place, don't pull it out, and fit another one and try again, making the appropriate adjustment in your aim.

A 3 port 2 position changeover valve is okay, they feed one or the other, never both. It is the 3 port mid position valve that by some trickery / bodgery can be made to stop half way and feed both together that I think is the work of the devil.

Go back to the company and say their advice was wrong. Was this funded by any sort of grant? If they won't admit they got it wrong, try trading standards. The ambition go go green is good, it is just a shame you have so far had bad advice from an installer.

Millions of people will learn this lesson the hard way, if the government gets their way and people do start en-mass swapping gas boilers for ASHP's with nothing else being done.

How is yours plumbed to switch between hot water and heating? two 2 port valves ore one 3 port valve? Try turning the hot water back on again and see if the fault comes back? I am not seeing anything in that photo that looks like a heat exchanger to me (does not mean it is not)

No that is not going to work like that. Contact LG directly. Don't say anything about install not finished, just say it is a new system just being started for the first time now, and it clearly is not defrosting as it should. Your supplier should also take the same view, shame you mentioned to him that the install was not finished as typical today everyone is looking for an easy get out clause to not address the problem. This is not something you can turn on or off or do manually so if it is not working it must be a fault. With it turned off you could try defrosting with warm water but unless the air temperature is now above zero, the water left on the evaporator will just freeze again.

It sounds like your ASHP installer has badly misled you. Perversely at the moment, it seems oil has gone up in price in the present cost of living crises less than gas and electricity has. But if you have been "sold" an ashp that only works properly if the radiators are ran at over 50 degrees, then that is a poor install. Unlike other heat sources ASHP's work best with low temperature water, so that usually means under floor heating or larger low temperature radiators. Even with everything just right, an ASHP will just about match the cost of for instance mains gas. They are not a magic cheaper form of heating, anyone telling you that is somewhere between optimistic and fraudulent. they do have environmental benefits, less CO2 emissions.

Can you post a picture? Do you have an IR thermometer so you can do a non contact temperature reading of a hard to reach part?

More details please, house type, age, insulation levels, and what heating was there befoer. Cheaper than what? Don't forget temperatures now are probably colder than you have had for a very long time, especially down south.

Which is why we should be investing in tidal power, that is absolutely predictable (all but minor differences due to air pressure)

So find the heat exchange in the outside unit. It will have 2 thin refrigerant pipes probably soldered, and 2 larger water pipes. If the refrigerant pipes are hot, and possibly both the same temperature, but the water pipes are cold, this suggests little or no flow through the water pipes to take the heat away. In normal operation you would expect one refrigerant pipe to be hot and the other to be less hot as the water will have removed some heat as it passes through the heat exchanger, and you would expect the water pipes to be warm. I had lots of low flow issues with mine when I first ran it and the best thing I did was bought a flow meter and connected that in line with the pipes to the outside unit so I could see what flow I was getting.

Hot pipe out of the compressor usually means the water is not removing the heat from the heat exchanger fast enough. I would look at your plumbing to ensure water is really flowing to the outside unit. It could be the pump is running but no flow due to ice or an air lock for example? Is the pressure high enough?

Planning does not usually set a time limit for completion. So it would still be a "work in progress" If the garage requires building regs approval then you would have to pay separately for that if you build it later. Could you at least put in the foundations and pour the slab, then it is an easy job to build later when you can.

Except the silly way we do things it would not surprise me if we mandated it has to be a type approved charger installed by some member of a special club who has been on the right course and will cost you ££££

Or just changing it for the non spyware version after completion sign off? Just more hops for a builder to jump through.

I think the high cost is the weather, not a "fault" If the UFH is failing to deliver enough heat to the rooms, then it will use less gas. If it is burning a lot of gas the heat has to be going somewhere. Don't confuse the higher cost of gas per unit with thinking it is burning more gas.