New A-rated boilers fitted by certified engineers — 10-year warranties available.
Open now · 24/7, Monday to Sunday
Plumbing, heating & boiler specialists in Hertfordshire & London.
Flowing with quality, warming with trust. Emergency repairs, boiler installation and servicing, gas safety, everyday plumbing and full drainage services — from a certified local team, with transparent pricing.
Transparent pricing before work begins 10-year warranties on new boilers
Check if we cover your area
24/7
Open Monday to Sunday
Boilers
Install · service · care plans
Drainage
OnDemand Drainage — drains, tankers & pumps
Herts + London
All 32 boroughs covered
Boiler brands we work with
Worcester BoschVaillantIdealBaxiGlow-wormViessmannAlphaMain
…and all major brands
Need help now?
Emergency plumbing & heating, 24/7
Water where it shouldn’t be, or no heat at all? Call and describe the problem — we’ll prioritise you and talk you through safe first steps.
Rapid response for emergencies across Hertfordshire & London.
- Burst pipes
- Leaks
- Blocked drains
- Blocked toilets
- No hot water
- Boiler breakdowns
- Heating failures
- Ceiling leaks
- Failed stopcocks
What we do
Plumbing & heating across Hertfordshire & London
From 24/7 emergencies to boilers, bathrooms and blocked drains — one certified team, transparent pricing.
Annual servicing that keeps your boiler safe, efficient and warranty-valid.
24/7Burst pipes, leaks, blockages and breakdowns — 24/7, Monday to Sunday.
24/7Blocked or overflowing toilets cleared fast — hygienically and without mess.
24/7New boilers
A boiler solution for every home and budget
We assess your home and recommend the right boiler — never the biggest margin. Every installation comes with transparent pricing and 10-year warranties available.
Flats & smaller homesCompact combi
- Fits neatly in a kitchen cupboard
- Instant hot water, no tanks
- Efficient A-rated models
Family homesPremium combi
- Higher hot water flow rates
- Smart thermostat compatible
- Longest warranties available
Larger homes, multiple bathroomsSystem + cylinder
- Strong mains-pressure hot water
- Runs several showers at once
- Pairs with Megaflo-style cylinders
Not sure which is right for your home? Call 07538 144040
See our Care PlansThe drainage arm of the On Demand family
OnDemand Drainage
Our dedicated drainage division handles everything below the plughole — with its own specialist team, vacuum tankers and survey equipment, on the same 24/7 promise.
Drains & toilets unblocked
24/7 emergency clearance
CCTV drain surveys
Footage + clear report
Vacuum tankers
Septic, gullies & flood water
Pumps & stations
Installed, serviced, repaired
Why choose us
Flowing with quality, warming with trust
Open 24/7, Mon–Sun
Genuine round-the-clock cover. Call 07538 144040 any hour, any day.
Certified engineers
Gas Safe registered engineers, adhering to all regulations.
Hertfordshire & all of London
Rooted in Hertfordshire, extending our expertise across every London borough.
Transparent pricing
A clear quote before any work begins — the fourth step of our published promise.
Get started
Book your service
Four quick details and we’ll call you back — or ring us any time, 24/7.
Call 07538 144040
Office: 0203 924 3334
Good to know
Frequently asked questions
Quick answers on coverage, boilers, gas safety and emergencies.
- Yes — we operate 24/7, Monday to Sunday. For emergencies call our 24/7 line on 07538 144040 any time; for general enquiries you can also reach the office on 0203 924 3334.
- We’re rooted in Hertfordshire — including Watford, St Albans, Hertsmere, Welwyn Hatfield, Broxbourne, Stevenage and Dacorum — and we cover all 32 London boroughs. Not sure? Send us your postcode and we’ll confirm.
- Yes — boiler installation is one of our core specialisms. We assess your home, recommend the optimal boiler system, install it using the latest methods and provide aftercare advice. 10-year warranties are available on new boiler installations.
- Yes. Our Boiler Care Plans combine annual servicing with priority callouts, so your boiler stays safe, efficient and warranty-valid without you having to think about it. See the Boiler Service Plan page for what each tier includes.
- Yes — we’re on the Gas Safe Register under registration number 654504, and we’re Checkatrade members too. By law, anyone working on gas appliances must be Gas Safe registered. Always ask to see the engineer’s Gas Safe ID card — we’ll never mind.
- We prioritise genuine emergencies — burst pipes, serious leaks, no heating in winter — and aim for rapid response across Hertfordshire and London. Call 07538 144040 and we’ll give you an honest arrival estimate.
Need a plumber or heating engineer today?
Call On Demand for emergency support, repairs, maintenance and installations across West and Central London.
+44 7538 144040 · Available 24/7 · Hertfordshire & London