Heat and water,handled properly.
Gas Safe engineers covering North and Northwest London and the Hertfordshire borders, 12 years in. We find the fault, tell you the price before we start, and leave the place as we found it.
- Out day or night, 7 days
- Gas Safe reg. 596868
- Rated 4.8–5 stars on Google & Checkatrade
- Fixed price before we start
Someone always picks up
24/7Emergency callout
Burst pipe at 2am? We answer the phone.
Emergencies don’t wait for Monday. We take callouts through the night and at weekends, across North and Northwest London and out to Watford and Borehamwood. The phone gets answered by an engineer.
Call us straight away for
- Burst pipe or water coming through a ceiling
- No heating or hot water
- Boiler leaking or locked out
- Overflowing toilet or blocked waste
Smell gas? Don’t call us first. Open the windows, leave the property, and ring the National Gas Emergency Service on 0800 111 999. It’s free and open 24 hours. Call us once you’re safe.
- 24/7 emergency callout,
- Burst pipes,
- Power flushing,
- Boiler repair,
- Central heating,
- Landlord gas certificates,
- Hot water cylinders,
- Gas leak detection,
- Carbon monoxide checks,
- Finchley,
- North Finchley,
- Barnet,
- New Barnet,
- Enfield,
- Camden Town,
- Hampstead,
- Mill Hill,
- Edgware,
- Stanmore,
- Willesden,
- Wembley,
- Pinner,
- Watford,
- Bushey,
- Borehamwood,
- Elstree,
Constantin Stahei · Founder, Gas Safe registered
- Gas Safe registered business,
- Worcester Bosch accredited installer,
- City & Guilds qualified,
- Continuous manufacturer training across the major UK boiler brands
Who you’re calling
I got tired of fixing other people’s work.
I qualified in carpentry and drylining, and spent about ten years on domestic and commercial sites. A lot of that time I was being called in to put right work someone else had already been paid for. The constant repairs, the lack of pride in a finished job. Eventually it pushed me to look for a trade that matched the standard I wanted to work to.
I moved into plumbing and heating expecting to find it. What I found was that shortcuts and unqualified installations exist here too. That didn’t put me off. It settled how I work. Every job gets done right the first time: clean, reliable, and built to last.
Twelve years on, I still bring the same attention to detail I learned in carpentry to every heating system I touch.
We install boilers from all the major manufacturers, Vaillant among them. The warranty is the maker’s rather than ours, so its length follows whichever boiler goes in and what’s fitted alongside it — 10 to 12 years on parts and labour at the top end, and several of them only give you that if a magnetic filter goes in with it. Whatever it comes to, it holds only while the boiler is kept up with an annual service. We’d rather say so here than leave you to find it in the small print.
- Installation warranty
- Up to 12 yr
- Gas Safe reg.
- 596868
- Emergency cover
- 24/7
- Google & Checkatrade
- 4.8–5★
What we do
Everything that carries water, gas or heat.
One team for the whole system, so nobody stands in your hallway saying it’s someone else’s job.
Water where it shouldn't be, at whatever hour it happens. Pipework replacement, leak detection, stopcocks, toilet and tap repairs, shower pressure, water tanks and immersion heaters.
Emergency plumbing & heating
Water where it shouldn't be, at whatever hour it happens. Pipework replacement, leak detection, stopcocks, toilet and tap repairs, shower pressure, water tanks and immersion heaters.
Gas safety inspections & certificates
Full inspection of appliances, pipework and ventilation. The CP12 certificate is issued digitally the same day, so you have it when the tenancy needs it.
Boiler repair & servicing
Inspection and servicing, breakdown cover, fault-finding on systems nobody else could work out, parts replacement, thermostatic radiator valves and gas appliance installation. If it can be repaired, we repair it.
Boiler installation
New boilers and full replacements, sized to the property, which often isn't what was there before. We fit all the major manufacturers, Vaillant among them, and the warranty comes from whichever one goes in — up to 12 years on parts and labour, depending on the make and on fitting a magnetic filter with it. Installations are registered with Building Control, and an annual service keeps the warranty live.
Power flushing & water treatment
We test the system water first, pH and dissolved solids both, so you know whether a flush is the answer before you pay for one. Then a hot flush and fresh inhibitor, and radiators that heat all the way to the top.
Hot water cylinders
Cylinder installation and replacement, servicing and repair, immersion heaters and controls. Sized around how much hot water the house needs at once.
Gas leak detection & carbon monoxide
If you can smell gas, ring the National Gas Emergency Service first on 0800 111 999. Once the supply is made safe, we trace the escape, test the pipework and put it right. We also investigate carbon monoxide: a sounding alarm, a yellow flame or sooting around an appliance all point at combustion that needs testing properly.
Radiators & thermostatic valves
Radiators that never heat, valves seized open or shut, and the pin under a TRV head that's stuck down after a summer of not moving. Repairs, replacements, balancing and relocations.
Landlords & managing agents
A different job from a homeowner call: compliance on a deadline, tenants to coordinate with, and often several units in one building. Certificates issued digitally the day of the inspection.
Gas hob installation
Hob and gas appliance installation and replacement. Connected, pressure-tested, left safe, with the paperwork.
What happens if you call
Four steps, no surprises.
- 01
You call, we answer
Emergency calls get answered quickly, day or night, and we aim to be with you fast when something has gone wrong. The person on the other end is the engineer who turns up.
- 02
We diagnose it properly
No quick fix that lasts a fortnight. We test, including the system water where that matters, and keep going until the fault is found. Then we explain what's wrong in language that means something.
- 03
You get a clear quote
A straight price before work starts, with no aggressive upselling and nothing added that you don't need. If the job turns out simpler than it looked, the price comes down with it.
- 04
Clean work, paperwork done
Your home gets protected and the area gets left spotless. Anything gas-related comes with its certificate, issued digitally the same day.
The work
The part you only notice when it’s wrong.
Photographs from real jobs. What the fault looked like, and what was done about it.
Power flushing
What comes out of a neglected system
A sample drawn before flushing. Black water means the inhibitor gave up years ago and the system has been eating itself since. That's why the radiators run cold at the bottom.
Water treatment
Testing before quoting
pH and dissolved solids measured on site, before anything gets quoted. The reading tells us whether a flush will fix the problem or whether something else is going on.
Hot water
Limescale inside a cylinder
London water is hard, and this is what a decade of it does. Scale like this is why the hot water runs out faster every year.
Boiler repair
Heat exchanger, stripped and cleaned
Blocked plates mean the boiler fires and fires without ever heating the house. This one was cleaned and refitted, and the boiler stayed where it was.
Leak detection
Going in to find a leak
Boards lifted to reach pipework under a radiator. We open the minimum needed to reach the fault, and put it back.
Gas work
New gas run, sleeved through
Sleeved where it passes through the structure, tested before anything is sealed up.
Parts replacement
Diverter valve on the bench
Laid out on a dust sheet, not on the carpet. It's a small thing, and it's the thing customers mention most in their reviews.
Central heating
A finished circuit
Run square, clipped at proper intervals, valves left where the next engineer can reach them. Doing it neatly costs no more than doing it badly.
What customers say
Judged by the people who paid for it.
Consistently rated 4.8–5 stars on Google and Checkatrade. Every review below is real and unedited. You can read them at the source.
“Like an artist”
Constantine came in to look at a boiler which had been deemed beyond repair. Like an artist he quickly dismantled it and slowly started bringing it back to life. It was fascinating to watch. Without a doubt someone who has mastery of his craft. Would highly recommend.
“Came the same day”
At no notice our boiler broke down in February. As it turns out it was full of sediment. The whole heating/boiler system needed cleaning out and the boiler needed a repair. Constantin came the same day, assessed the problem and carried out the necessary work without delay. He explained what needed doing effectively and I have been impressed with his level of work, effective, detailed and courteous.
Brigitt Angst · Google
“No job is too small”
Over the years he has done boiler servicing, power flushing, toilet repair and refurbishing, even a single tap fitting — no job is too small. Most recently he installed a new boiler and water softener for us. He is prompt, courteous, meticulous and his work is of the highest quality.
Jim Wharmby · Google
“Professional and reliable”
A brilliant company. They installed my new boiler, built a brand new and bespoke pipe network for the gas in my home and regularly maintains my entire home system. Always professional and reliable, which is not what you can say about the rest of the industry.
Matt Garcia · Google
“Totally trustworthy”
If you need a boiler fixed, call Constantine. You definitely won't regret it. I've used his service many times and each time fixed my boiler without fuss. Always does a good clean job. Totally trust worthy and knows what he is doing.
Kamran Qureshi · Google
“Found a hidden leak”
Constantine has done a number of plumbing jobs for me over the years including finding and fixing a hidden leak. He has always been very polite and professional and is reasonably priced as well. I would thoroughly recommend him.
David Elvey · Google
“The undisputed champion of Power Flush”
Mr. Stahei is beyond doubt one of the most thorough, professional and courteous tradesman we have ever met. He was engaged to flush our central heating system and repair our boiler. He performed an immaculate job; there is no other word but 'immaculate' to describe his work. He was always willing to explain everything that he did.
Checkatrade customer · Checkatrade, November 2016
Where we work
North & Northwest London and the Hertfordshire borders.
Based in Colindale, covering North and Northwest London and out across the Hertfordshire border to Watford, Bushey and Elstree. If your area isn’t on the list it’s still worth a call. We cover more than we can fit here.
- North London
- Finchley,
- North Finchley,
- Barnet,
- New Barnet,
- Enfield,
- Camden Town,
- Hampstead
- Northwest London
- Mill Hill,
- Edgware,
- Stanmore,
- Willesden,
- Wembley,
- Pinner
- Hertfordshire borders
- Watford,
- Bushey,
- Borehamwood,
- Elstree
Get it looked at
Tell us what it’s doing.
If it’s leaking now, call. The line is answered around the clock. For anything that can wait, this form is the quickest way to a straight answer and a price.
07525 379063- Office
- 020 8259 2036
- Address
- 11 Firefly, Little Strand, London NW9 5PT
Booking hours
- Monday – Saturday
- 8am – 6pm
- Sunday
- Emergency callout only
- Emergency callout
- 24 hours, 7 days
Services: Emergency plumbing & heating, Gas safety inspections & certificates, Boiler repair & servicing, Boiler installation, Power flushing & water treatment, Hot water cylinders, Gas leak detection & carbon monoxide, Radiators & thermostatic valves, Landlords & managing agents, Gas hob installation.