Heat Pump or New Boiler?
An Honest Guide for Suffolk Homes

Let me be straight with you from the first line: I'm a Gas Safe registered engineer. I fit gas boilers, not heat pumps, so I've no reason to sell you one — and no reason to rubbish them either. What I see, week in and week out, is people trying to make a big and expensive decision while the whole debate is drowning in sales pitches from both sides.

So this is the honest version. A heat pump is the right choice for a lot of homes. It's the wrong choice for others, and a handful of people are paying good money to have one taken out and gas put back in. The difference almost always comes down to the home and the quality of the installation — not the technology. Here's how to work out which camp you're in.

First, the honest bit — heat pumps genuinely work

It would be easy for a gas engineer to write a hit piece on heat pumps. I'm not going to, because it wouldn't be true. The largest national survey of UK heat pump owners to date found that around four in five were satisfied with their system — as satisfied or more than with the gas heating they had before, and across every type of property. When a heat pump is installed in a suitable home and set up properly, it does the job quietly and well, and it produces far less carbon than burning gas.

Keep that figure in mind whenever you read a scare story. The failures are real, but they're the minority — and they cluster around a few avoidable mistakes rather than proving the whole idea doesn't work.

So why are some people going back to gas?

When a heat pump gets ripped out within a year or two, it's rarely because the unit was faulty. It's usually because it was sold and fitted badly. The most common story goes like this: the existing radiators were left in place with a vague assurance they'd “probably be fine,” nobody actually calculated whether they could throw out enough heat at a heat pump's lower temperatures, and come the first cold snap the house wouldn't warm up.

The homeowner then does the natural thing and cranks the flow temperature right up to force more heat out of those radiators. It works — the rooms get warm — but it wrecks the efficiency that makes a heat pump worth having in the first place. Run hot enough for long enough and a heat pump can end up costing more to run than the gas boiler it replaced. That's the point at which people lose faith and call someone to put gas back in.

The number that quietly decides it: flow temperature

This is the bit the glossy adverts skip. A gas boiler happily sends water round your radiators at 65–75°C. A heat pump is at its most efficient running that water much cooler — around 40–45°C. A radiator gives out far less heat at 45°C than at 70°C, so to keep the room just as warm it often needs to be physically bigger, or a higher-output type.

In a well-insulated house that loses heat slowly, the sums usually work with modest or no radiator changes. In a draughty, solid-walled house that loses heat quickly, you may need to upsize a lot of radiators — sometimes most of them — before a heat pump can keep up at an efficient temperature. That's not a reason to rule it out, but it is a cost that belongs in the quote. If you're weighing up radiator changes either way, our radiators & heating upgrades page explains how sizing affects a system.

The single best thing you can do before spending a penny is insist on a proper room-by-room heat-loss survey. Any installer worth using will do one. If someone quotes you for a heat pump without measuring your home's heat loss and checking every radiator against it, walk away.

What it actually costs to run in 2026

Here's the maths that matters. Under the current price cap, electricity costs roughly three to three-and-a-half times as much as gas for each unit of energy. So a heat pump only saves you money if it's efficient enough to more than make up that gap — producing at least three-and-a-half units of heat for every unit of electricity it draws. A good install in the right home clears that bar comfortably. A poor one doesn't.

Figures are broad guidance for a typical Suffolk home in 2026, not a quote. Your actual costs hinge on insulation, how you use your heating, and your electricity tariff. Insulation is the single biggest lever.

The honest verdict: which suits your home?

The Suffolk angle

Mid-Suffolk has a lot of older housing — period cottages, solid-wall Victorian terraces, farmhouses out in the villages around Stowmarket, Eye and Debenham. These are exactly the homes where a heat pump needs the most careful design, because they lose heat quickly and the radiators are often small. It can absolutely be done well, but it's the wrong place to cut corners on the survey.

One honest exception worth flagging: if you're out in a village with no mains gas and you're currently heating with oil or LPG, the case for a heat pump is genuinely stronger — you're comparing it against expensive fuel, not cheap mains gas. That's not work I do (I'm a mains gas engineer), so I'll happily point you towards a reputable, accredited heat-pump installer rather than pretend otherwise.

My honest advice, whichever way you lean

Common questions

If you've weighed it up and a new gas boiler is the right answer for your home, my 2026 boiler cost guide sets out realistic Suffolk prices, and the boiler replacement page explains what's included in every installation.