{"id":117,"date":"2026-07-31T12:07:00","date_gmt":"2026-07-31T12:07:00","guid":{"rendered":"https:\/\/lloydsgas.co.uk\/blog\/?p=117"},"modified":"2026-08-06T12:15:27","modified_gmt":"2026-08-06T12:15:27","slug":"retrofitting-an-ashp","status":"publish","type":"post","link":"https:\/\/lloydsgas.co.uk\/blog\/retrofitting-an-ashp\/","title":{"rendered":"Retrofitting an ASHP"},"content":{"rendered":"\n
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How much extra work is needed in older homes?<\/mark><\/h2>\n\n\n\n

Quick answer:<\/strong> Yes, you can retrofit an air source heat pump in an older UK home\u2014and no, it doesn’t mean ripping everything out. The amount of extra work depends on your home’s insulation, radiator sizes, pipework, and hot water setup. A proper heat loss survey is the essential first step that shapes every decision that follows.<\/p>\n<\/div><\/div>\n<\/div><\/div>\n<\/div><\/div>\n\n\n\n

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Older homes and heat pumps have a bit of a reputation problem. Ask around and you’ll hear things like “you need to tear out all your radiators” or “Victorian houses just aren’t suitable.” It makes sense that people are sceptical\u2014nobody wants to spend serious money on a heating system that underperforms.<\/p>\n\n\n\n

But here’s what those conversations usually miss: the biggest factor in a successful retrofit heat pump UK installation isn’t the age of the building. It’s the quality of the design. A well-designed ASHP system in an older home can be every bit as effective as one fitted in a new build\u2014it just needs more thought upfront.<\/p>\n\n\n\n

So what does that extra thought actually involve? Let’s go through it.<\/p>\n\n\n\n

What an ASHP needs to work well<\/h2>\n\n\n\n
\"air<\/figure>\n\n\n\n

Air source heat pumps<\/a> run most efficiently at lower flow temperatures than a traditional gas boiler\u2014typically around 35\u201345\u00b0C rather than 70\u201380\u00b0C. That means the system needs to run longer and steadier to heat your home, rather than blasting hot water through at high temperatures for short bursts.<\/p>\n\n\n\n

This matters in older homes because systems designed for high-temperature boilers sometimes need adjustments to work well at lower temperatures. Radiators sized for 80\u00b0C flow won’t output as much heat at 45\u00b0C, pipework that’s partially restricted can create flow problems, and controls that expect a boiler’s quick-fire response need reconfiguring. None of these are dealbreakers\u2014they just need to be identified and planned for.<\/p>\n\n\n\n

Start with a proper heat loss survey<\/h2>\n\n\n\n

This is the bit most guides skim over. It’s also the bit that determines whether everything else goes well or badly.<\/p>\n\n\n\n

A room-by-room heat loss calculation tells us exactly how much heat each room needs to stay warm on the coldest day of the year. From that, we can work out what size heat pump<\/a> your home actually needs, whether your existing radiators are up to the job, and what flow temperature the system should be designed around.<\/p>\n\n\n\n

According to Heat Geek, an older Victorian or Edwardian building with basic insulation upgrades (double glazing, a bit of loft insulation) typically has a heat loss of around 65\u201385W per m\u00b2. A well-insulated pre-2006 newer build, by contrast, might be 30\u201350W per m\u00b2. The difference changes everything\u2014and it’s why we don’t guess.<\/p>\n\n\n\n

At Lloyd’s Gas & Renewables, our heat loss surveys take one to two hours on site. We measure every wall, window, and door; check your loft and cavity insulation; and size every radiator in the house. If an engineer hasn’t done that before recommending a system, they haven’t done a heat loss survey\u2014they’ve done a rough guess.<\/p>\n\n\n\n

If you’d like us to take a look at your home, get in touch for a free, no-obligation consultation<\/a>.<\/p>\n\n\n\n

The ‘extra work’ explained (bucket by bucket)<\/h2>\n\n\n\n
\"air<\/figure>\n\n\n\n

Insulation and draught-proofing<\/h3>\n\n\n\n

The better your home holds onto heat, the smaller and cheaper the heat pump needs to be\u2014and the lower the running costs<\/a>. Before or alongside an ASHP install, it’s worth considering:<\/p>\n\n\n\n