Some of your advice is irrelevant if the installer has disappeared

@Graham Brennand, if your installer has disappeared, which, as many of us know from these forums, is unfortunately all too common, there are still several avenues you can explore for support and the advice in the video is still valid. First, you can reach out to another qualified heat pump installer to assist you. Many reputable installers are experienced in taking over systems from previous contractors and can help with everything from basic servicing to advanced troubleshooting.

Additionally, contacting the manufacturer directly is often a great option. Most major heat pump brands, like Mitsubishi, NIBE, etc. have customer service lines and homeowner support departments that can provide guidance on system settings, troubleshooting or accredited  installers in your area.

Lastly, one of the key reasons these forums exist is to empower homeowners to learn and make small adjustments themselves, especially if it’s a settings issue. With the collective knowledge shared here, it’s entirely possible for homeowners to fine-tune their system and ensure it’s running efficiently. Sometimes, all it takes is a minor tweak to the weather compensation settings or flow temperature to see a noticeable improvement in performance.

I wish I had known about you before I had the pump fitted. This is my
first winter with the pump.

Sadly it is all too common that the first winter is a nasty shock for new heat pump owners. There is nothing about this in any government information and many of the official or semi-official information sources that promote the mass market installation of heat pumps. You could be forgiven for thinking that they are trying to mislead us. For example the BBC is a major culprit. The Radio 4 You and Yours programmme has covered heat pumps several times but is relentlessly positive and there's never a mention of the problems that are frequently documented on this forum.
After 7 years of ownership I'm no longer shocked. It seems to be partly a feature of heat pumps although mostly incorrect installation of them by plumbers/heating engineers who only really understand the gas and oil fired boilers they've been installing for years and continue to do so in large numbers.
Having got to a tolerable (but definitely not desirable £200 per month) level of electricity bill I now just live with it having wasted a lot of money on no nothing installers. To fix it would probably incur costs worth several years of potential energy savings. I'll face up to the whole problem properly when the heat pump needs replacing.
Although no longer surprised or shocked I found the first 2 weeks of January 2025 have been the coldest start to a year since I started tracking the numbers. I had 11 straight days when my ASHP went into a defrost cycle as it cleared the frost build up multiple times a day (how do these things work in colder climates than the UK). It used 795kWh in the first 14 days with a peak of 79kWh on a day when the outside air temperature dropped to -6C. That's an average of 57kWh per day when my overall average for the year is about 20kWh per day (itself a poor number). I'm sure we could heat our very well insulated house through the coldest days with electric fan heaters for less than this!
My recommendation to friends who ask me about heat pumps is to do all the insulation they can before thinking of anything else and then only consider a heat pump if they can be absolutely sure they have found a competent designer and installer for the system. (and then to give me the name of them!)
Mike
 
 

Agree, its down to installers and how they fit the system , I too have had for 8 yrs now and the installers disappeared as a company after 6mths of install . Yes bg problems including finding an electrician after 7yrs of an extremely gutsy system .  Insulation has been added below the floor but not much else. The months of Jan would in the first week when cold was around 89kw.  13TH -20TH Jan 139.64kw , so a bit hard going in a 4 bedroom bungalow.

Yet I am still trying to tweek the system!

Just to put the other, more positive side of this argument, I have now had my heat pump for just over a month and, because the temperature has been all over the place, have enough data on its performance at a range of temperatures to get a pretty reasonable prediction of energy use vs OAT.  I also have my gas consumption for the past three seasons as well as the temperature profile for those same years, from which I also have pretty accurate figures of gas use vs OAT. 

Since I have both gas and ASHP consumption vs OAT, and the OAT profiles for three seasons, I can work out, to a sufficient degree of accuracy, the comparative costs and can say with a reasonable degree of confidence, that the ASHP is costing about 10% less than gas when compared on a like for like basis.  I would say this is +/- 10% at present so worst case it's break even, which was my aim.  I have ignored any potential savings in standing charge from cancelling the gas altogether, because I still have a (now very expensive to run ) gas hob.

There is nothing 'clever' in the system (perhaps that's the whole point), its just a direct connection between ASHP and central heating, running it on pure WC with most (not quite all) radiators open loop.  The design FT is 45 @ -2, Im actually running at more like 42@-2.  The house is if anything slightly warmer than when I was burning gas, and certainly heated more consistently.  I have a simple electricity tariff (Eon Next Drive) with 7 hours cheap rate, Im not yet doing much with the ASHP to optimise for that so there may be some modest further savings to be made by having a night time 'set-forward'.  Currently I'm paying on average 20p/kWh for the leccy.  If I had gone for the OvO heat pump tariff the ASHP would be even cheaper (15p/kWh), but I also have an EV and in total I would end up paying more this way.

Of course the consumption in the coldest days was a bit scary, but they don't happen that often and my energy company pretty much insists I pay level instalments throughout the year so in terms of cash I don't actually see this.

Before I got my heat pump I was convinced that the industry is making this all too complicated, Im now even more convinced.  How difficult is it really for heating engineers to connect an ashp directly to a central heating system without any intervening unnecessary parts?  The guy who did it certainly worked very hard for long hours, but it wasn't rocket science!

I should acknowledge the help of everyone who contributed to this forum in helping me understand the questions to ask installers before choosing them!

 

Posted by: @mike-patrick

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Although no longer surprised or shocked I found the first 2 weeks of January 2025 have been the coldest start to a year since I started tracking the numbers. I had 11 straight days when my ASHP went into a defrost cycle as it cleared the frost build up multiple times a day (how do these things work in colder climates than the UK). It used 795kWh in the first 14 days with a peak of 79kWh on a day when the outside air temperature dropped to -6C. That's an average of 57kWh per day when my overall average for the year is about 20kWh per day (itself a poor number).

Vaillant have this comment about de-icing "The de-icing cycle will happen more often when the outside air temperature is around 2.5°C but will happen less often when the air temperature is below 0°C, as there is less water in the air" page 4 of https://professional.vaillant.co.uk/downloads/product-brochures/22006-heat-pump-leaflet-v05-web-2-2343880.pdf. We in UK have the wrong sort of weather!
I'm in my first winter with a heat pump and, so far, the energy consumption has provided no unwanted surprises. 11th January had a mean daily temperature of -3.8C and my 7kW Arotherm+ used 28kWh of electricity to produce 108.6kWh of heating and hot water. I had most of the radiators replaced with bigger ones as part of the heat pump installation and my target was a maximum 35C flow temperature for all but the most severe conditions so it's roughly performing in line with what I had hoped for. I have to note that, as a retired engineer, I tried to understand as much as possible about heat pumps before asking for quotes so that I could understand what was being proposed. The only unwanted surprise was, at the end of the installation, I asked about servicing and was told that an annual service was needed (to maintain the warranty) and would cost about £250.