It was inevitable really. I’m a life-long environmentalist who got solar panels 15 years ago, an EV 11 years ago, and a battery a few years ago. I also spent my own money to madly build a 1.23MWP solar farm. Of course I was going to get a heat pump. In fact you may well have assumed I already had one. Why was I not earlier to this?
We live in a very old house. Its funny because where I live, its just considered an ‘old’ house, because there are so many here, but by most people’s standards its ludicrously old, as it was built in 1750. Living in a house like this is kinda awesome, if you like BBC costume dramas, and it certainly has a lot of ‘character’, but there are definite drawbacks. One is that it is quite cold, as the walls are single-thickness, without cavities, and the other is that you need government permission to change anything.
When heat pumps first came out, there was definitely a vibe o ‘well its cool if you have a passivehaus’ and then things migrated to be ‘its great as long as you have underfloor heating and excellent insulation’. This was still no good to us, as our floors are either suspended wood over a cellar, or brick and huge chunks of stone. Underfloor heating would never be a thing here. But then heat pumps got better and better, and we managed to (finally) get double glazing, and it actually looked like getting a heat pump might work for us.
Quotes and Grants
Luckily a neighbour of ours already had one, so we went and gawped at it, and asked questions etc. (They have a newer house). Eventually we decided to go for it, and got quotes. Oh my god the quotes. First we needed to get an ‘Energy performance certificate’ for our house, which basically means pay £100 to some freshly qualified surveyor who walks around your house and fills out a form. Like many govt programs, this was a big waste of time, because although you need the certificate, the govt dropped any limit on how efficient the house had to be before getting a grant for a heat pump. The certificate is thus just a piece of paper that gets stuck in a drawer that was pointless, but we had to do it anyway.
Why did we need it? Well because the UK government, for all its sins gives you £7,500 towards a heat pump, and that certificate process is the only string attached. So well worth it. Why did they drop the efficiency limit? Well someone in govt finally worked out that the only people getting heat pumps installed were retired middle class people who tended to live in old houses. If the efficiency limit was too strict, they wouldn’t bother, and they need ‘early-adopters’ like us to kick-start uptake of heat pumps. Getting the grant was satisfying because I have NEVER got a grant from the govt to do anything (not even the solar farm).
Anyway, grant plus paperwork in place, we got three companies to give us heat pump quotes. One was just totally useless. Another did an exhaustive heat-loss survey, but all of the numbers were blatantly just wrong. We eventually went with a third (which our neighbours used), and they were tons better. Basically they need to come measure your rooms, look at your radiators, do a ton of calculations and decide what size heat pump you need, and if you need to upgrade radiators. We were told we needed a 14KW heat pump, and no urgent radiator upgrades. In the end we doubled the size of two of them anyway, in rooms that were always cold.
We then needed ‘listed building consent’ and ‘planning permission’, and that was an epic world of stupid stupid pedantic pointless government bureaucracy bullshit I won’t bore you with, because unless your house is listed, you wont need it.
The Installation
And so it came to pass that people came and installed a heat pump. Yay. Because we had previously had an outside oil combi-boiler, our house had zero hot or cold water tanks. So we needed one of those. And luckily, it went in our cellar, which is where we put stuff like batteries etc. This was awesome as it meant taking up zero room in the house. I was impressed that the installers were not put off by having to install a hot water tank and ton of heating controls down some tiny steps in a cellar, especially as the door to the cellar is actually a secret door that works as a bookcase. Its all very scooby do.
Anyway, after a few days of fuss, we ended up with this!
And if you think ‘seriously thats a lot of tubing’ I agree with you. I had it all explained to me, but I zoned out a bit. It looks more complex than it is, and you can basically ignore it all and just use a tiny little remote thermostat gadget to control it all that looks like this:
And of course the actual heat pump got installed (which was way quicker) and the old boiler removed. It went in the exact same place and is here:
I should point out this is a BIG heat pump for a 1750s 3 bedroom detached house. If you have an average UK terraced house a heat pump would be 5-8kw. Ours is 14kw. Also worth pointing out that although the total cost for our heat pump massively exceeded the £7.5k grant, that would be VERY different for a typical smaller one, especially if you already have a hot water tank and don’t need it installed somewhere awkward.
So the heat pump was installed, and everything was great. The end.
The difficulties and the fix
But no! It was an irritating nightmare of unhappiness for a few weeks. We had major problems. Firstly it seemed like it used a TON of electricity to do NOTHING. It then seemed that it COULD generate hot water (and lots of it), or hot radiators, but never under our control. It was frustrating and disappointing and I was unhappy :(. We argued and complained a bit. We also decided to double the size of one of the two radiators in our living room. This was a good move and made a big difference, BUT what totally transformed everything was the radiator dude spotting that the ‘Hysteresis’ was set wrong. This is a setting that determines how much the heat pump lets temperatures diverge from the thermostat before switching. Heat pumps do NOT like to be constantly going on and off. Insanely ours was set to 20 degrees, when it should have been 8 or even less. So our heat pump would be told to get the radiators to say 50 degrees, do it, then switch off and not care about switching back until they were 40. The same happened with hot water. It also controls how much you can overshoot, so a Hysteresis of 20 means radiators oscillated from 40 to 60.
In practice what this meant is that it all felt RANDOM. Sometimes radiators were super hot, often seemingly cold. Ditto hot water. It felt like the whole system was under someone else’s control. It sucked. We had heat-pump-purchase regret. But actually the minute that setting got changed, everything then worked perfectly, and we are very happy. The house is warmer than ever.
Its worth pointing out we had several conversations with the installer, lots of emails and frustration before eventually it was spotted that this was wrong. We are so glad that we persevered to make sure it was set up correctly, instead of just being grumpy and mumbling that ‘heat pumps suck’ which I think some people do when they have this problem. Check your settings!
The conclusions
So… was it a good idea? Well actually YES. If you read my blog you know I would do it anyway. Its about the environment for me, not money. I HATED buying thousands of litres of oil to heat our house, and wanted to remove my last direct usage of fossil fuels. But actually now its all set up right and we have the right radiators, its pretty good. And our timing was comically good. Not only was our oil tank 99% empty when they took the old boiler away (luck!), but just as we are settling in to our oil-free lifestyle, the Iran war starts and the price of heating oil has more than DOUBLED. Our electricity bill is definitely a lot higher, but then we now have zero oil bill. Plus we had the heat pump fitted in winter, so it was always going to be the most expensive time to assess how much power we now used.
So, my tips for anybody considering it? Firstly I would say shop-around and read reviews. Some installers are good, some not. Same as anything. Ask neighbours who have had one fitted for references. Secondly, take any recommendations about new radiators seriously. We were a bit flippant. We should have got that radiator fitted at the same time. Thirdly, Make sure its set up right. They are COMPLEX and you need it set up right for your lifestyle and your home.
But generally, I am very happy. Out of solar, batteries, EV and heat pump, this was the most disruptive and hardest upgrade. However if you are in the UK don’t delay. That govt £7,500 grant will NOT be around forever. Take advantage of it. Oh and if you are thinking of getting solar or a battery, GET LOTS. We have gone from smugness about our 4.1kwp solar and 19kwh batteries to ‘Balls, I wish we had more…’. A heat pump does push up how much electricity you use, so generating more and storing more off-peak power will be well worth it.