About Thermalwerk
The London home climate specialist homeowners actually recommend.
We design, install, service and repair the systems that keep London homes warm in winter, cool in summer, and quietly comfortable the rest of the year.
The story
Built from a long-standing London heating business.
Thermalwerk is the residential-focused trading name of 3F Heating & Plumbing Ltd — an MCS-certified, Viessmann-trained, Daikin-approved London heating installer with years of happy customers across the capital.
We started Thermalwerk because the market changed. Homeowners today are weighing up heat pumps against boilers, thinking seriously about air conditioning, adding underfloor heating during extensions — and almost nobody is helping them think about the whole system together.
So we built a brand that does exactly that. One team. Every service. No commission-driven upsells, no "we only do gas", no "you need to find another company for that bit". A proper home climate specialist.
Principles
How we work, in plain English.
01
We answer the phone.
Same-day reply to every enquiry during business hours. The thing everyone says they do, and most don't. It's the simplest promise we make, and the one customers thank us for most.
02
We specify honestly.
If a boiler is the right answer for your home, we'll say so — even when the heat pump makes us more money. If a cheaper unit will do the job, we'll quote for it. You get the system that fits your home, not our margin.
03
We quote properly.
Fixed written price after a proper survey. Not "from £X" brochure numbers that move on install day. If we miss something, that's our risk to carry — not yours.
04
We keep dates.
Install days are booked and kept. If something unusual happens, you hear about it straight away — not after the van doesn't turn up.
05
We finish the job.
Full commissioning, written handover, photos of concealed pipework. Warranty registered. Serviced a year later. The bit most installers treat as optional is where we earn the repeat business.
06
We pick up afterwards.
Something's not right six months in? Call us. It's a cliché that matters — the measure of a good heating company is how they behave when the job has already been paid for.
Credentials
The badges that actually matter.
MCS certified
Microgeneration Certification Scheme — required to install heat pumps under the Boiler Upgrade Scheme grant.
TrustMark · Government Endorsed Quality
Government-endorsed quality mark for tradespeople. Independent quality and compliance checks.
RECC · Renewable Energy Consumer Code
Consumer protection for renewable energy installations — mandatory code of practice for MCS-certified installers.
Viessmann Trained Installer
Manufacturer-trained on the full Viessmann boiler range. Unlocks the 12-year extended warranty for our customers.
Verified by Expert Trades
Vetted trade directory — credentials, insurance and customer reviews independently verified.
Plus Gas Safe registered and F-Gas certified engineers on every relevant job, full public liability and employers' liability insurance. Certificates and registration numbers available on request before any work starts.
Where we work
Greater London, end to end.
All 32 Greater London boroughs plus the City of London. Most of our work is inside the M25 — we don't travel far outside because we want to be the team that answers the phone when you call us three years after the install.
See all 32 boroughs we cover →Key areas
- Kensington & Chelsea
- Westminster
- Hampstead
- Notting Hill
- Islington
- Camden
- Richmond
- Dulwich
- Clapham
- Hackney
- Greenwich
- Wandsworth
Talk to us
Tell us what you're trying to do.
We'll call back the same working day, talk through your options, and book a free home survey if it's the right next step. No pressure, no hard sell.