MCS-certified · Boiler Upgrade Scheme · London
Heat pump installation done properly.
Quiet, efficient, low-carbon heating that works with your existing radiators and hot water. We size it right, we install it properly, and we help you claim the full £7,500 Boiler Upgrade Scheme grant.
The basics
What is an air source heat pump?
A box that sits outside your house. It extracts heat from the outside air — even when it's cold — and uses a refrigerant cycle to upgrade that heat to a temperature useful for your radiators and hot water. It's the same physics as your fridge, in reverse.
For every unit of electricity you put in, a well-designed system gives you roughly three to four units of heat. That's what makes them economic to run, and why the Government is backing their adoption with a £7,500 Boiler Upgrade Scheme grant.
Heat pumps run cooler than a gas boiler — around 45–55°C on the flow, rather than 70–75°C — which means some homes need larger radiators or better insulation for the system to work at full efficiency. A proper survey tells us what your home actually needs.
Why Thermalwerk for your heat pump
The industry is full of companies who'll sell you a heat pump. We design systems that actually work in real London homes.
We size it, we don't guess.
Full MCS-compliant heat loss calculation, room by room. If your radiators or emitters need upgrading, we tell you up front — in the quote, not three weeks into the job.
BUS grant handled.
The £7,500 Boiler Upgrade Scheme grant is deducted from your quote. We do the paperwork. You don't see the government admin at all.
Quiet where it matters.
We specify units with genuinely low sound output, site them thoughtfully, and use anti-vibration mounts as standard. Planning-compliant noise levels for London permitted development.
Proper commissioning.
Weather compensation curves set for your home, hot water schedules that match your usage, a written commissioning document you actually get a copy of. Not just "switched on and left".
Clean install.
Pipes boxed properly, cables discreet, outdoor unit sited in a way that doesn't ruin your garden. If the finish matters to you, it matters to us.
Aftercare that answers.
Annual servicing, warranty admin on your behalf, and a human on the phone when something needs fixing. The stuff that happens after the install is where most companies fail.
Common questions
The things homeowners always ask — answered straight.
Will a heat pump work in my London home?
Almost always, yes — if it's designed and installed properly. We've fitted heat pumps in Victorian terraces, Georgian townhouses, 1930s semis, and modern flats. The real question is not "can it work?" but "does the emitter sizing need upgrading, and by how much?" A proper survey answers that.
How much does it cost after the grant?
A full heat pump installation typically sits between £9,000 and £16,000 depending on home size, emitter upgrades required, and cylinder changes. The £7,500 Boiler Upgrade Scheme grant comes off that total. We give you a fixed, written quote after the survey — no hidden extras.
Will it be noisy?
Modern heat pumps are genuinely quiet — comparable to a fridge at a few metres distance. Planning permission rules in England require noise levels below 42 dB(A) at the neighbour's window, and we specify accordingly. Sited well, you won't hear it from inside the house.
Do I need planning permission?
Usually no — heat pump installations in England are covered by permitted development rights if the unit meets MCS-020 noise limits and is sited more than a metre from the boundary. Conservation areas and listed buildings are different. We check all of this for you as part of the survey.
How long does the install take?
Typically three to five working days on site for a full swap-out including cylinder and pipework changes. We schedule installs around your calendar — no arriving on a Monday and disappearing until Thursday. You'll have a named lead engineer for the whole job.
Customer stories
What homeowners tell us after the install is finished.
Placeholder reviews shown while we build a verified Google and Checkatrade profile.
Replaced our old combi with a heat pump. Quiet, much cheaper to run, and the team left the plant room tidier than they found it.
Rachel M.
Dulwich · Heat pump
Underfloor heating across the ground floor with a heat pump. The detail in their design brief was genuinely impressive. No surprises on site.
Anita R.
Hampstead · Underfloor and heat pump
We had three quotes for a new Viessmann boiler. Thermalwerk was not the cheapest, but they were the only ones who actually explained the sizing.
David K.
Islington · Boiler replacement
Talk to us
Think a heat pump might be right for your home?
The only honest way to know is a proper survey. We'll come out, measure up, and tell you whether it's the right call. If it's not, we'll say so.