When we moved into our house almost three years ago, there was a list as long as your arm of things we had to do to make it suitable for modern living. From a new roof and insulation to a new layout and upgraded wiring and plumbing — I included everything I could think of from my years of working in homes journalism and previous experience renovating. One thing that we knew we had to do from day one was replace the oil boiler that we estimated to be at least 30 years old.
Every time my Mum visits she mentions the smell of oil in the house, plus the inefficient boiler breaks down every six months or so. So it's definitely time for it to go. So I started to research our options.
Ideally, we would prefer not to use oil anymore for the same reasons we wouldn’t consider installing gas (not that it’s an option in our village anyway!). One option that seemed to tick every box was a heat pump, specifically an air source heap pump, but as I dug deeper, it turned out it wouldn't be as suitable as I thought. Here's why.
Why a heat pump wouldn’t work in our house
This is our long, narrow access path that runs down the garden alongside the house. About halfway down there a slightly wider part where we wanted to put the heat pump.
After getting multiple quotes on how much a heat pump would cost from various heat pump providers, it was only when someone actually came to my house for the heat loss assessment that I really came to terms with the difficulties of installing a heat pump in our home. In my mind, the heat pump was going to go just outside the bathroom and utility room, as well as being cost-effective and simple to install. But sadly that wasn't to be the case.
Firstly, our house is in a conservation area and there are restrictions on what can and can’t be installed on the front elevation without planning permission so that meant were relegated to the back of the house when it came to installation points. (If you don't live in a designated zone like I do, installing a heat pump may actually be one of those home improvements that doesn't require planning permission, but you should always check with your local authority).
Next, we have a very narrow walkway running down the back of the house with the external wall opposite a retaining wall for a section of the garden. When the assessor came, he indicated that because of the size of the house (~180m2) we would need a larger heat pump than I had imagined. This would leave us with just 60cm of walkway space. I also hadn’t anticipated that best practice with heat pumps is to have them set away from the wall by 10-15cm, further reducing our access to a measly 50-45cm.
One option was to reduce the size of the retaining wall for the garden, and another was to install the heat pump where the oil tank currently stands and dig out a trench for the required connections to the hot water tank. Both would vastly increase the cost of the heat pump, completely negating the cost benefits with the Boiler Upgrade Scheme discounts that made it so appealing
That means we were back to square one and in still desperate need of replacing our boiler. So what are our options now?
What heap pump alternatives could we choose?
Now that I know a heat pump wouldn't work in my home, I need to go back to the drawing board. From my research, I have three feasible options to choose from.
Our work-horse oil boiler - while it has done well for many decades, it's time for it to retire
1. Another oil boiler
The simplest option for us would be to replace like-for-like with a new oil combi boiler. I’m pretty sure anything would be more efficient than our current 30-year-old model. In the last three decades there have been huge improvements in the condensing technologies that our boiler relied on.
However, despite the planned 2026 ban on new oil boilers, similar to the gas boiler ban, being delayed until 2035, there is obviously an issue with burning fossil fuels in our homes.
I can foresee that the costs of oil instability getting progressively worse, meaning our savings in the long-run wouldn’t be as incentivising. Moreover, making our home more environmentally friendly was one of the major benefits of installing a heat pump in the first place and I feel guilty every time I order an oil delivery.
2. Electric boiler
Not only would the next possibility, an electric boiler, be quieter to run, it would also remove the chance of oil smells in the utility and reduce our dependence on fossil fuels (to a degree, as electricity often comes from fossil fuels). Plus, it would be installed in the same place as our current boiler with minimal fuss.
However, it may well be more expensive to run than our current oil boiler, despite a cheaper initial installation cost, and it won’t work during power cuts (something we, for some reason, get fairly frequently in our area).
We spent £1,066 for 1,500l of oil last year and with the current price of electricity being around 27p, it would cost at least double per year to heat our four-bed house. Generally speaking, electric boilers are considered to be more cost-effective in smaller properties than ours.
3. Biomass boiler
My favourite option and the one we’re most likely going to choose is a biomass boiler. My old boss installed one in his house and at the time it sounded really counter-intuitive. They work by burning wood pellets or similar fuel, and in my head I very much conflated them with old-fashioned woodburning stoves and the negativities surrounding the emissions. However, after a little digging, it seems the particulate filters on biomass boilers mean they actually cause very little air pollution.
My research says a biomass boiler would suit a house our size better than an electric boiler, and it means we would be less dependent on fossil fuels. It's also a much more environmentally friendly option than either of the other two choices we were facing.
While they are more expensive than either oil or gas boilers, they’re eligible through the Boiler Upgrade Scheme, although the discount is not as much as for a heat pump. Approximate running costs for the biomass boiler we'd go for seems to be around £800-900 per year, depending on usage, which would be a saving for us.
The only draw back for us is the space required, both for the boiler and hopper system, and for the pellet/fuel storage.
So plenty for my partner and I to think about, and I'll be sure to fill you in on the option we end up going with. In the meantime, I've been sharing more tips from our renovation, from how I fixed our draughty front door in just five minutes to the instant benefits we felt from upgrading from single to double glazing.