Boiler and Plumbing Engineer in Hemel Hempstead
Heating Engineers in Hemel Hempstead
Local, Gas Safe registered boiler and plumbing engineer covering Hemel Hempstead and the surrounding area. Fixed prices, no call-out fee and a one year guarantee.
Information on this page last reviewed October 2026.
Gas Safe boiler engineers and plumbers in Hemel Hempstead
Hemel Hempstead was drawn on a plan before it was built. Dacorum's planning strategy calls it a Mark One New Town designed by Geoffrey Jellicoe in the 1940s, with development starting in the 1950s, and Historic England dates his masterplan to 1947. For a boiler engineer that has a practical meaning: the town is a set of neighbourhoods built in different decades, with different houses and, as it turns out, different water. Home Comfort Assured is a Gas Safe registered firm based in Watford, number 586325, with no call-out fee. Boiler replacements, servicing and repairs are most of what we do here, with plumbing alongside. The number is 07970 632 064.
What we do
Our services in Hemel Hempstead
Boiler repairs and servicing
Breakdowns, fault finding, annual servicing and replacement, on every major brand.
Read moreCentral heating
Radiators, valves, controls, power flushing and full system installation.
Read morePlumbing
Leaks and burst pipes, taps, cylinders, bathrooms and appliance installation.
Read moreUnderfloor heating
Design, installation and repair, wet systems in new builds and retrofits.
Read moreViessmann boilers
Why we are accredited, what the range does well, and how it compares.
Read moreLocal knowledge
Why Hemel Hempstead customers call us
A Mark One New Town, 1947
Dacorum's own planning strategy calls Hemel Hempstead a Mark One New Town designed by Geoffrey Jellicoe, and Historic England dates his masterplan to 1947. Its neighbourhoods were built to a plan, decade by decade, so the housing changes from one to the next.
35.1% terraced, 27.1% rented socially
Summing the town's twelve Census wards gives 35.1% terraced homes against 23.2% nationally, and 27.1% socially rented against 17.1%. Only 13.5% are detached. It is a town of small and medium houses, not large ones.
Three zones, three readings
Affinity's lookup returned 283 mg/l for most of Adeyfield, Highfield and Grovehill, and 320 and 305 for Gadebridge and the town centre. On Affinity's own scale the first is hard and the other two very hard.
Where the Gade meets the Bulbourne
The council's flood assessment says the Gade, the Bulbourne and the Grand Union Canal meet at Hemel Hempstead. The rivers join at Two Waters, and the council's three Section 19 reports here cover Apsley, Boxmoor and the King's Copse estate.
79% built from 1973 to 1982
That is the share of Woodhall Farm's 2,570 homes in the Valuation Office's 2025 figures, with Grovehill mostly 1965 to 1982. Highfield, Warners End and Chaulden are mostly 1945 to 1972, so a boiler's age follows the neighbourhood.
One conservation area, and a printed flue rule
The Old Town has been a conservation area since 7 October 1968, and Dacorum's 2012 appraisal prints the rule on flues facing a highway. Piccotts End is the only other one in the town.
On the ground
Areas we cover in Hemel Hempstead
We cover HP1, HP2 and HP3.
The Old Town
HP1The High Street and the medieval core, with the Grade I church of St Mary. A conservation area since 1968, and the one place in Hemel where Dacorum prints a flue rule.
Boxmoor
HP1Beside the Bulbourne and the canal. A draft council report from June 2026 covers a 2020 storm that flooded five properties inside on Kingsland Road, Fishery Road, St Johns Road and Horsecroft Road. Water here is mixed between two zones.
Apsley and Two Waters
HP3The old mill village where the Gade and the Bulbourne meet. Four commercial properties on London Road and a house on White Lion Street flooded inside in September 2016, when the drains were overwhelmed.
Gadebridge and Warners End
HP1Gadebridge Park is where the Gade has come out of its banks, in March 2007. Gadebridge water mostly falls in Affinity's Hemel and Potten End zone. In the Census area covering Warners End and Gadebridge, 1,910 of 2,800 homes date from 1955 to 1964.
Highfield, Grovehill and Adeyfield
HP2Neighbourhoods that are almost all in the 283 mg/l zone. Highfield has the highest share of social renting in the town at 39.9%, and the surface water hotspot the council modelled, near Queensway.
Woodhall Farm and Leverstock Green
HP2Woodhall Farm is 79% built between 1973 and 1982, with 23.1% of households on electric heating alone. Leverstock Green is 25.7% detached, the highest in the town.
What a New Town looks like in the Census
There is no published Census table for Hemel Hempstead as a town, because it has no parish, so the figures here come from adding up its twelve Census wards. The sum describes a place quite unlike its neighbours. 35.1% of households live in terraced houses, against 23.2% across England and Wales, and only 13.5% in detached ones. 25.4% live in purpose-built flats against 16.7% nationally. 27.1% rent from a council or housing association, against 17.1%, and 15.4% rent privately, against 20.3%. The Town and Country Planning Association's fact sheet records that in 1966, 69.2% of the town's housing was socially rented.
The wards vary widely within that. Adeyfield West, Chaulden and Warners End, Gadebridge and Grovehill are all about half terraced or more. Hemel Hempstead Town ward, the centre, is 47.9% flats. Highfield has the highest social rented share, 39.9%. Leverstock Green is the most detached at 25.7%, and Boxmoor the most owner-occupied at 68.1%. None of this says what boiler you have, but it says what kind of house the boiler is probably in: smaller, often rented from a landlord, and often in a street built to a pattern.
A decade at a time
The Valuation Office's 2025 figures show the New Town growing outward, and they are the nearest thing to a build date we can give, because the council documents we read do not give start years for each neighbourhood. In the area covering Woodhall Farm, 2,040 of 2,570 homes, about 79%, date from 1973 to 1982, and nothing is earlier than that. Grovehill is mostly 1965 to 1982. In the area covering Highfield, 41% of homes date from 1955 to 1964. In the area covering Warners End and Gadebridge, 1,910 of 2,800 homes, 68%, date from 1955 to 1964, and in the Chaulden area 1,170 of 2,120. Leverstock Green is 43% from the same decade.
The oldest stock is elsewhere. Apsley and Boxmoor mix pre-1919 houses with recent ones, with about 18% built before 1919 in the area covering both, and a further 840 homes from 2000 to 2008. The Old Town is older again, with a medieval core.
What this means for a boiler is simple. Streets built together tend to share a layout and a pattern of pipework, so what we learn about one house often applies to its neighbours. What matters is what is in the loft and under the floor now, not what the original builders intended.
Three water answers
Affinity Water supplies Hemel Hempstead, and its own postcode lookup names the supply zone for each address. The answer is not the same across town, and unusually we can say how it varies. Of 503 postcodes we sampled across HP1, HP2 and HP3, most of Adeyfield, Highfield, Grovehill, Leverstock Green and Bennetts End, and about half of Apsley, fell in the zone called Hemel Hempstead, where the 2025 report gives total hardness of 283 mg/l. Affinity's published scale calls 151 to 300 hard.
Gadebridge was mostly in a zone called Hemel and Potten End, at 320 mg/l, and the town centre mostly in Hemel and Kings Langley, at 305, and Affinity's scale calls anything over 300 very hard. Boxmoor was split between the Hemel Hempstead zone and the Hemel and Kings Langley one. Each figure is one sample in the year, and the zones cut across streets, so Affinity's checker is the way to know your own address. The practical difference is how fast scale builds in a heat exchanger or around a cylinder's element, and whether it is worth fitting protection on a new installation.
Where the rivers meet
The council's flood assessment says that the Rivers Gade and Bulbourne, and the Grand Union Canal, flow through the borough and meet at Hemel Hempstead. The Bulbourne passes Boxmoor and joins the Gade at Two Waters. Hertfordshire County Council, which investigates floods, has written three reports here, and they describe three different events.
At Apsley, in September 2016, 48 millimetres of rain in 1.75 hours overwhelmed the drainage and flooded four commercial properties on London Road and one house on White Lion Street inside, to depths of between 76 and 400 millimetres. The report says the water did not come out of the river. At Boxmoor, a 30-minute storm in August 2020 flooded two properties on Kingsland Road and one each on Fishery Road, St Johns Road and Horsecroft Road. At the King's Copse estate, off Green Lane, Storm Alex in October 2020 flooded five properties inside when a balancing pond owned by Thames Water overflowed and the estate's drainage was overwhelmed. Two of those three reports are drafts published in 2026 and one is a 2022 draft, so their findings may yet be revised. Separately, the council's assessments record that the Gade came out of its banks in Gadebridge Park in March 2007, and name Highfield, Adeyfield, Chaulden and Warners End among its surface water hotspots.
We are heating engineers, not flood specialists, and almost every boiler in the town is nowhere near any of this. It changes one thing. If a boiler, cylinder or pump sits in a cellar or at the bottom of a hill on one of those roads, it is worth asking whether it should stay there.
The Old Town and the flue rule
Hemel Hempstead has two conservation areas, the Old Town, designated on 7 October 1968, and Piccotts End, designated in 1969. The Old Town's appraisal, published for Dacorum in 2012, says in its section on planning controls that installing, altering or replacing a chimney, flue or soil vent pipe on the wall or roof slope that fronts a highway, and forms the principal or side elevation of the house, will need planning permission. It is the same sentence Dacorum prints for Berkhamsted. A flue out of the back of a house is not caught. Dacorum's table of Article 4 directions, the tool councils use to take permitted development rights away, has no entry for Hemel Hempstead, and Boxmoor, Gadebridge and Apsley are not conservation areas. The Old Town is also where the Grade I church of St Mary stands, and the majority of its buildings are listed, so a flue there is a conversation about the building as well as the rule.
The town is not inside the Chilterns National Landscape. The Chilterns Conservation Board says its boundary does not include major towns and that Hemel Hempstead is just on the doorstep, so the stricter rule that applies on that land does not reach it.
Gas, electricity and the town centre
Mains gas is the norm. Across the twelve wards 79.1% of households heat with gas alone, and oil, bottled gas, wood and solid fuel together account for 0.8%. The exceptions are in the centre. In Hemel Hempstead Town ward 20.0% of households heat with electricity alone and 66.6% with mains gas alone, and in Woodhall Farm the figures are 23.1% and 65.4%. We work on gas only. If your home is one of the electric ones, or runs on oil, we are not the right firm and we would rather say so on the first call.
Plumbing
Leaks, taps, burst pipes and bathrooms are the other half of what we do, and there is a plumbing page with the detail. Elis Harizi does all our bathroom work. Andrew does none.
Who does the work
Andrew Millward has been in the trade for forty years, is a Heat Geek Elitist and is Viessmann accredited. We service and fit all the major makes of boiler.
Around Hemel Hempstead
Up the Bulbourne, Berkhamsted has its own page and its own conservation area, and its flue rule is the same sentence as the Old Town's. St Albans and Watford, where we are based, each have a boiler installation page.
To book a service, have a fault looked at or get a replacement boiler priced, call Andrew or Elis on 07970 632 064.
Need us in Hemel Hempstead?
Call and speak to the engineer who will do the work, or ask for a quote. No call-out fee, and a one year guarantee on what we do in Hemel Hempstead.
Step by step
Booking a boiler engineer in Hemel Hempstead
Hemel Hempstead was built neighbourhood by neighbourhood, so we start with where you are.
Ring and say what is wrong
Call 07970 632 064 and tell us what the boiler is doing, or what you want to replace. You speak to Andrew or Elis.
Tell us the road and the type of home
The road tells us the neighbourhood, the likely age of the house and which water zone you may be in. Whether it is a house or a flat decides who has to agree to what.
Gas, or something else
We work on gas only. If the home heats with electricity or oil we will say so at this point, not later. There is no call-out fee.
The work
Andrew or Elis does the job. Bathroom work is Elis's, and Andrew does none.
Common questions
How hard is the water in Hemel Hempstead?
It depends on the road. Affinity Water's own postcode lookup put most of Adeyfield, Highfield, Grovehill and Leverstock Green in its Hemel Hempstead zone, where the 2025 report gives 283 mg/l, which Affinity calls hard. Gadebridge and the town centre fell mostly in two other zones at 320 and 305 mg/l, which Affinity calls very hard, and Boxmoor was split. Each figure is one sample in the year, so check your own address on Affinity's postcode checker.
My boiler is in a flat. What is different?
The flue rules and who decides. Flats and maisonettes have no permitted development rights, so a flue on one is a planning question from the start. There is often a freeholder or managing agent as well, and sometimes shared pipework. Hemel Hempstead Town ward has nearly half its households in purpose-built flats, so this comes up, and it is better asked early.
Do I need permission to move a flue in the Old Town?
Dacorum's own appraisal for the Old Town conservation area says that installing, altering or replacing a chimney, flue or soil vent pipe on the wall or roof slope that fronts a highway, and forms the principal or side elevation of the house, needs planning permission. A flue out of the back of a house is a different matter. The rule is printed for the Old Town and Piccotts End, not for the rest of the town, and we found no Article 4 direction in Hemel Hempstead that covers flues.
Do the Apsley and Boxmoor floods affect my boiler?
Only if the boiler, a cylinder or a pump sits low. The council's investigations into floods in Apsley and Boxmoor were about intense rain overwhelming drains, not rivers coming out of their banks, and they flooded a handful of properties on named roads. Most boilers are nowhere near any of it. If yours is in a cellar or a ground floor utility on one of those roads, it is worth discussing where it could go.
Do you work on electric heating or oil?
No. We are gas engineers. About 79% of households across the town's Census wards heat with mains gas alone, but in Woodhall Farm 23.1% and in Hemel Hempstead Town ward 20.0% heat with electricity alone, so a gas engineer is not the answer for everyone. If you have electric heating or oil, we are not the right firm.
Are you Gas Safe registered?
Yes, number 586325, which you can look up on the Gas Safe Register. The engineer carries their card.
Recent work nearby
See more of our work
What our customers say
See more reviews on TrustATraderWe were very lucky to have Elis for our new boiler installation. Due to the structure of the flat there were a few awkward points, but Elis was determined to get it right without compromising the quality. His pipework is like beautiful artwork. Highly recommend.
Elis was absolutely fantastic. Very clear, explained everything, was a tidy worker and did a brilliant job. Thank you Elis!
I had two people in to try to fix a few heating issues in my rental house and both kept making the job bigger than it was. One phone call and Andrew explained the various options. He sorted out the whole system, gave me a breakdown of his labour costs and did not overcharge me on parts. The tenant is very happy.
Meet your engineers
The engineers who turn up
Two engineers, both Gas Safe registered under registration 586325. When you book Home Comfort Assured, this is who does the work.
Andrew Millward
Founder and heating engineer
- 40+ years experience
- Heat Geek Elitist
- Viessmann accredited
Andrew has over 40 years in the trade and specialises in fault finding, boiler and heating repairs, and the design of energy efficient systems like heat pumps and underfloor heating.
Andrew on YouTube
Elis Harizi
Director and plumbing & heating engineer
- Plumbing since 2007
- Heat Geek member
- Gas qualified
Elis trained as a plumber in Greece in 2007, moved to England to gain his gas qualifications, and now designs and installs energy efficient heating as a Heat Geek member.
Got a job that needs sorting?
Call and speak to an engineer, or request a quote. No call-out fee, and we work across Hertfordshire and south Buckinghamshire.