Yes, I Got a Heat Pump or, Why Greta Loves Me Longtime

Photo by alpha innotec on Unsplash

Previously, on “Heat my House”

My house is a fairly typical Swedish design, built in the 60s ( it’s 2 years younger than me) with hot water radiators. The whole house, including the heated cellar, is 250 sqm. The typical lowest temperature that we see, at my place, is about -20C though we’ve seen -30C a few times.

When I first moved in, it had the original wood powered boiler, pretty inefficient and mucky. I later replaced this with a modern high tech (wood powered) boiler with fan assisted combustion and 2 x 750 litre water tanks (accumulator tanks) which keep the heating going after the fire goes out. This was much more efficient, and almost as mucky as the original. Finally, about 6 years ago, I spent 400 quid on a second hand pellets burner, and converted my boiler to use that. Pellets can run 24-7, as long as the hopper is filled up. Still mucky….

Why, why why?

In the spring of 2023, with my (and Swedish tax office) bank accounts, freshly filled with pension money, I decided the time was ripe for me to spend it on a new boiler, powered by the modern miracle of the fridge acting in reverse.

I’m Not an Eco-Loon

As a retired Antarctic hero, you might think that I am some sort of eco-nutter. However, the opposite is true. I worked in the trade, as it were, and I am well aware of the flakey science that is involved. As a believer in the scientific method, I remain utterly unconvinced of our impending demise because cows fart, and people (try) to live in comfort. So, no, I’m not saving the planet.

Getting Reamed

Pellets are a product of wood based industries such as saw mills.Pellets used to be cheap (2 years ago). Then there was a mishap with a pipe between Russia and Germany, and Swedish pellet producers realised that they could make the Swedish tax office very rich by selling most of their product to Germans. This led to a difficult and expensive winter for us Swedish pellet burners. The price more than doubled and, even worse, pellets were difficult to find. I had to search online everyday and, on one occasion, I had to drive 200Km from Gothenburg with 20 x 16Kg sacks in the back of my car.

At this point I started to think about those nifty “bergvärme” things that many of my neighbours have.

But They Don’t Work!!

If one reads the comments, one would be fully aware that heat pumps don’t work, and anyone heating their house with one, is sitting in their front sitting room in abject misery (and a down jacket).

According to my neighbours, however, they do work, and their houses always seem warm and cosy when I visit.

I think some of the confusion may be caused by the plethora of heat pump technologies. They vary. Actually the heat pump bit is pretty similar in all of them, the difference is the input heat source (to be pumped) and how the heat is distributed in the house.

Excuse possible made up names as heat pumps weren’t a thing when I left Engerland, so I’m more familiar with the Svenski names….but, off the top of my head, there is:

Type Input Output Notes
Air-Air Air of course Air of course Tend to get a bit inefficient when it’s below -15. Needs 1970s, futuristic, open plan house
Air-Water Air Water (in radiators) Same inefficiency at lower temps but sensible heat distribution system
Ground Source Long pipe in river or pond Water (in radiators or under floor) Efficient but you need a water feature
Ground Source Long pipe winding around under your garden Ditto Efficient, but requires ruining your garden
Ground Source 14cm diameter hole down to 150m or more (depending on output required) Ditto Most efficient, less damage to garden


One common mis-conception is that ground-source heat pumps are “geo-thermal”. Sadly, this is not true. The heat they collect is from the sun warming the top layer of the planet (200m is just a pinprick).

Another common belief is that “you have to have underfloor heating, or they don’t work”. This might have been true 20 years ago but these days they can produce temperatures that work fine with radiators. In fact my heat pump has a special mode to limit the water temperature for underfloor heating, to prevent damage..

Options in Sweden

We are a bit short of heating options in Sweden. We have:

  • Gas: Just kidding, ain’t no gas mains in Sweden, bro
  • Oil: Robbing barstards charge heating oil at exactly same rate as car diesel
  • Wood in various forms
  • “Direkt-el”: 1970s style electric heating without efficiency of heat-pump
  • “Fjärrvärme”: (CHP) Waste heat from power stations and paper mills. Only if you live near one.
  • Heat pump (electric)
  • Unicorn Farts – used by Greta and other rich people in Stockholm

I Want an Easy Life!

The number one reason for (me) getting a heat pump is: TaDah!!! CONVENIENCE. Of course, this does not apply in the UK, where you can use a nice gas boiler.

I’m getting old and don’t want to be carting 16kg sacks up and down, buying them every week, cleaning out the soot and ash, with sacks taking up space in my car port.

I don’t have to do anything with the heatpump. It stays on all year round and works out if I need heating or hot water. If I want to change the temperature, when I’m travelling, I can use the phone app, but I don’t usually bother.

Secondly, I don’t want every horizontal surface in the house to have a fine layer of soot / ash that finds its way into the air.

Thirdly, it is cheap to run (see below) if you use it properly, though I will probably snuff it before I recoup the capital invested.

How Much?

Motivated and ready to embrace the furious pumping of heat, I contacted two local firms via their websites back in the spring of 2023. The aim was to have everything up and running before winter. Unfortunately, their response time left much to be desired. Yes, “craftsmen” are just as useless in Sweden as in the UK. Months later, they coincidentally called me on consecutive days to arrange a visit.

The salesman / plumber (1), who visited, assessed my boiler room, confirmed that I would want the cellar heated and decreed that my magic number would be 12kW. Salesman (2) arrived the next day and came to the same conclusion as salesman from company number 1. He promised me a quote “this week”.

A couple of days later, I received two quotes from company 1 for roughly the equivalent of £12,000 and £15,000 at the current SEK/GBP exchange rate. The cheaper quote was for the “non-inverter” machine (output is regulated by the pump switching on and off). The higher quote was for the “inverter” boiler where the pump speed is continuously variable. It had a few more fancy features and was technically more efficient, so I accepted the higher quote. The price was all in, including equipment, labour, bore hole drilling, electrics and removing my old boiler and tanks.

The other company remained silent, possibly overwhelmed with work, or bone idle.

It turned out that my neighbours had used company 1, the previous year, and were happy to recommend them.

Permits and Permissions

As in the UK, the local council are affiliated with the Cosa Nostra, and need their palms greased before you do anything. This means paying 1000Kr for absolutely nothing except an email granting permission, which took the lazy fuckers 3 weeks, and several reminders from the plumbing company, to produce. I also had to get permission from my neighbour for the hole because it was less than 10 metres from his boundary (it was 9.8m). Luckily, he’s a “trevlig gubba” as we say in Svenski, and happily signed my homemade permit-to-drill.

Now, with all my permits in hand, the plumbers instructed the drilling company to come to my place ASAP, which turned out to be about 10 weeks later….

Drill My Hole (baby)

I received a mysterious phone call one Saturday night, in early January. “Shall we come over and drill your hole on Monday?”. Yes I said (stop sniggering at the back).

I was quite surprised that they would do it now, as we had shed loads of snow and the temperature was hovering around -20 during the day – but boring through a frozen garden probably isn’t a big deal for a machine that will shortly be drilling through 200m of granite.

I got up extra early on Monday to start moving the snow, so that their vehicles had somewhere to park. Our road was ploughed during the night but that left bloody great big snow banks blocking access to my driveway and making the street very narrow. So I spent nearly an hour shovelling. Luckily I am in my prime……

They turned up at about 8am. Two blokes in a big lorry with a sort of container on the back, which was for collecting the spoil, and towing a large trailer which had the drilling rig plus a huge compressor which was used to blow the spoil out of the hole somehow. Anyway, it seemed to work. All they needed from me was a connection to a tap, and they were up and running within 30 minutes.

During the initial drilling, they pushed down sections of stainless-steel pipe, until reaching the bedrock (around 12 metres deep). Once they reached the rock, drilling became significantly faster and they had reached the 200m depth by lunchtime. I have to credit them for working the whole day without a “fika paus” (tea break), very unusual in Sweden and what’s more it was bloody cold out (below -15)

Pipes and Connections, a near-death experience

After extracting the drill string, they lowered a heat collection pipe – a double plastic pipe with a U-shaped connector at the bottom – into the borehole. This process took 10 minutes. The stainless-steel pipe was then capped, and the crew departed.

The next two days, I was on a job in Norway and received another mysterious phone call from a bloke talking about leaving a mat at my house and was it ok if he “plugged it in”. Er…yes, I replied. I remember this conversation well because, while I was trying to understand the mystery caller, I came extremely close to being run over by a Norwegian train. Remember kids, don’t talk on your mobile while working in a train depot!

When I got back from Norway, there was a yellow plastic mat thing, laying on my grass between the borehole and the house. It was a sort of industrial electric blanket and was used to defrost the ground before the next stage which happened the next day, when a man with an excavator arrived, to dig a trench between the borehole and my cellar wall. He then drilled two holes through the wall (about half a metre below the surface) and inserted two pipes – one for inflow and one for outflow – into the boiler room.

The Installation

Exactly a week after the drilling crew left, the installation team arrived. Snow still blanketed the ground, and I spent another hour clearing a path and the driveway for their equipment access. While I was grabbing a cup of tea, they somehow managed to manoeuvre the bulky heat pump down into the cellar – impressive work!

Unfortunately, another business trip to northern Sweden awaited. I entrusted them with a key and hoped for the best. Amazingly, just a day later, I received a call amidst the freezing -25°C weather, informing me that the heat pump was installed, operational, and switched on! I was impressed by their heat-pump-installing zeal.

The team had also cleared out the boiler room entirely. This included the hefty old boiler itself, the accumulator tanks from my previous system (I’d already removed the pellets hopper and burner to smooth the process). They hauled it all away in a trailer, leaving the room mostly empty. A few jobs remained, like removing the old boiler’s metal flue protruding from the wall. I plugged the resulting holes with a towel to prevent warm air from escaping up the chimney.

Freezing (Heat Pumps Don’t Work)

Returning home, from up north, I noticed that my house was somewhat parky (“See! Heat pumps don’t work!”).

I had been away for 2 days and the weather had been a bit nippy, with temperatures reaching -18°C at my house. Since the heating had been off, and the cellar door was open, for two days during the installation, the house had got “a bit” cold..

Heat pumps operate by measuring the outside temperature and referring to a (user adjustable) graph to determine the water temperature needed for the radiators. It probably also does some other calculation based on the temperature of the returned water from the radiators…but who knows?

Unlike my old system, which constantly maintained 80°C water, the heat pump system relies on variable water temperatures and it is usually recommended to open the thermostatic radiator valves fully, and leave everything to the heat pump.

This approach has a drawback: if the house is extremely cold, as mine was upon when I came home, it takes a long time to reach a comfortable temperature. However, once up to a sensible temperature, the thermal mass of the house, and the crap within, helps keep that temperature steady. In fact, once the inside temperature climbed to around 22°C, comfort was restored, and it has remained that way ever since. The only adjustments I’ve made are minor tweaks to the reference graph to reduce the heat at lower outside temps. When the temperature fell below -20, it was heating the house to +24, which was a bit warm for me.

A Backwards Magic Fridge. Cleaning Not Required

Heat pumps all work the same, but have different heat sources to be “pumped”. In my case, the heat is extracted from a water / anti-freeze mixture circulating through the pipe in the borehole.

In essence, the incoming water is refrigerated and returned to the borehole. As many will have noticed when cleaning behind the fridge, it gets quite hot back there. Your fridge is a heat pump. In this case, the heat, resulting from refrigerating the borehole water, is used for warming the house and hot water. The lovely part of this is that, for my  heat pump, I get out nearly 6 times what I put in so, if I input a KW of pumping and refrigeration, I get 6KW out. Which sounds like magic, but it’s physics or summink.

During winter, the water returning from the ground isn’t very warm, typically around 3°C. The heat pump then utilises refrigeration technology to extract heat from this water. The cooled water, which can be around -1°C, is then sent back down the borehole.

Now that we are enjoying the Swedish summer, the incoming water is [runs downstairs to check…] 20.1°C

The heat pump system also has a built-in direct immersion heater as a backup for situations with exceptionally high heating demands. However, this feature only activates when absolutely necessary. In my case, the immersion heater has only run for a total of 9 hours – all on the first day when the house was extremely cold. Since then, the entire heating process has been handled by the refrigeration circuit.

Money, Feck, Arse

I experienced a bit of a jolt with my first electricity bill after the heat pump installation. At the time, I had a monthly priced contract with a rather dodgy calculation method, using some sort of magical average monthly supply price. Given the cold weather and the extra effort required to bring the house back up to temperature, my January bill reached a staggering £600! Needless to say, this caused some concern.

However, I decided to take action and switched to an hourly contract. This contract is based on the hourly changing Nordic energy market price.

The good news is that my heat pump connects to the World Wide Web Information Superhighway and knows what the current and predicted prices are. It then decides when to turn on and off. It operates similarly to the old storage heaters and, during cheapo hours (usually at night), raises the house temperature slightly above the set level. This stored heat then helps maintain a comfy temp during the day, with the pump running less frequently and the temperature gradually returning to the setpoint.

This has resulted my leccy bills have seen a significant drop since switching to the hourly contract. The very next bill came in at a mere £30! With warmer weather,  the heat pump primarily focuses on hot water production, but the heating has also switched on a few times during “The Hottest June Evah” but the cost is barely noticeable.


I’m happy, for all of the reasons I outlined at the start. I’ve completely renovated  the boiler room, which is now completely clean. I use it as an additional store room. I’ve also just finished renovating the adjoining laundry room, which was also covered in soot (not ideal for laundry) and now it looks lovely.

Should I Get One of These if I Live in the UK?

No. Because you have gas boilers.

Plus: unless you have a lot of space, a cellar, and a convenient garden, it will be impractical. Swedish houses are typically different from 300 year old houses in England, so it can work here.

Plus: the 30 grand price that I have heard quoted for UK installations is more than double what it costs in Sweden, so someone is getting ripped off.

© EJ 2024