Specialists in boilers, underfloor heating, bathrooms and unvented hot water systems. Gas Safe registered, exacting about the finish, and trusted in some of Hertfordshire's finest homes.
High-efficiency boilers specified, installed and certificated to manufacturer standard. Vaillant is our first choice; we're happy to quote for any make. Get an instant guide price →
True mains-pressure hot water for homes with multiple bathrooms. G3-qualified installation, certification and annual servicing.
Warm floors and clear walls. Designed from your drawings, zoned room by room, and finished with intelligent controls.
Extensions, renovations and new builds, delivered from first fix to commissioning in step with your builder and architect.
Leaks, breakdowns and the everyday jobs that keep a home running. A prompt, tidy call-out service has been part of the firm since day one.
Underfloor heating is a signature of ours. Whole ground floors, single extensions, screed or timber floors. Every system is designed from the drawings before we arrive, so each room receives precisely the heat it needs, and every zone runs on its own thermostat.
Loops, zones and manifold position worked out from the drawings before we're on site. Flow rates balanced per room, not guesswork.
Every zone gets its own smart thermostat, so bedrooms, bathrooms and living space each run at their own temperature and schedule.
UFH runs at much lower water temperatures than radiators: comfortable rooms with less energy, and it pairs perfectly with modern condensing boilers.
No radiators means every wall is usable. It makes a real difference in kitchens, open-plan living space and bathrooms.
Much of our work is complete properties for builders and architects. Send the drawings and we'll price the job precisely, with clear inclusions, then deliver to your programme. Recent projects include whole-house systems with underfloor heating across the ground floor, boiler and cylinder installations in the loft, and multiple bathrooms in between.
“We are delighted with the high quality and finish of our new bathroom installed by Inline Plumbing. The whole team was friendly, highly skilled with incredible attention to detail, and very tidy!”
Julie W.Bathroom installation“James and the team did a great job installing our underfloor heating. They worked quickly, efficiently, and were polite and respectful. We've since recommended Inline to others.”
Richard P.Underfloor heating“I called them with a leaky water cylinder and James was very prompt to come over, assess and quote me for the job. The work was completed quickly and professionally.”
Zoe S.Call-out & repairYou'll always know what you're paying before we start. Rates below apply from 1 January 2026; all prices exclude VAT. The first-hour charge covers travel, trips to suppliers for parts, and job admin. No surprise extras.
| First hour | £110 |
| Each additional 30 min | £50 |
| Out-of-hours emergency | £180 |
| First hour | £130 |
| Each additional 30 min | £60 |
| Out-of-hours emergency | £200 |
| Boiler service (incl. flue analysis) | £110 |
| CP12 / Landlord Gas Safety with service, per appliance; +£25 each extra | from £50 |
| Unvented cylinder service annual G3 safety & performance check | from £110 |
Emergencies during working hours are charged at standard rates, with no extra call-out fee; urgent jobs (major leaks, no heating or hot water, boiler breakdowns, gas concerns) are simply prioritised where availability allows.
Out-of-hours call-outs (evenings, weekends, bank holidays) are reserved for genuine emergencies and subject to engineer availability.
Materials are itemised on your final bill; a 15% markup may be applied to cover material expenses. Larger works (boiler installations, bathrooms, full projects) are quoted fixed-price in advance.
We can offer a free quote based on a remote conversation, or we charge our basic call-out rate to survey your system in person and provide a written quotation detailing the works involved.
Our engineers are fully qualified and hold the relevant accreditations for gas appliances and unvented hot water cylinders. You'll receive the relevant certificates on completion, giving you peace of mind that everything is done to current standards and regulations.
Absolutely. We've provided a call-out service since we began, and we have no plans to stop.
Yes. We hold the relevant insurance to cover all eventualities. You can rest assured you're in safe hands.
St Albans and Harpenden are the heart of our practice, and we work across Hertfordshire for homeowners, landlords, agents, builders and developers:
Call or email for a free quotation. If we can't answer immediately, leave a message and we'll return your call the same day.
info@inlineplumbers.co.ukInline Plumbing and Heating Ltd
4 Grovelands, Boundary Way, Hemel Hempstead HP2 7TE
| Mon – Fri | 08:00 – 16:30 |
| Sat – Sun | Closed (emergency call-outs by arrangement) |
Our engineers are Gas Safe registered. Check the register at gassaferegister.co.uk