For homes off the mains gas network, oil remains the practical way to heat the property and its hot water. We install, service and repair domestic oil-fired boilers and advise on tank siting and condition, for homeowners and landlords across the rural parts of Farnham, Guildford, Godalming, Farnborough, Fleet, Camberley and the wider Surrey, Hampshire and Berkshire countryside.
Around 4% of UK homes are off the mains gas grid, and in the villages and outlying properties around Farnham, Guildford, Godalming and Fleet, oil remains the most common way to heat a property with no realistic gas connection. An oil-fired system burns kerosene delivered to a storage tank on the property, rather than drawing gas from a main — done properly, it is as reliable as a gas system.
The differences that matter are the tank, the fuel delivery, and a service regime built around OFTEC standards rather than Gas Safe ones. This page covers the whole of that service — installation, servicing, repairs and tanks — for homeowners and residential landlords.
ComGas Services UK Ltd Gas Safe · OFTEC · REFCOM F-Gas · CHAS · Constructionline
What our residential oil heating service covers
Installation, servicing, repairs and tanks — the complete picture.
Each of these is a genuine discipline in its own right. For now, all four sit together here as the complete answer for a homeowner searching for oil heating support.
Installation & Replacement
Surveying the property, sizing the new boiler correctly, and installing or replacing an oil-fired boiler and its associated pipework and flue.
Regular (heat-only) boilers for the most common domestic arrangement
System boilers for mains-pressure hot water where more than one bathroom draws at once
Condensing boilers as the standard specification for new installations
Room-sealed or open-flued configuration confirmed against the property
Fuel line and tank confirmed suitable for the new boiler's requirements
Oil boilers share one principle, but the configuration is what matters.
Domestic oil boilers burn kerosene (Class C2 heating oil) through a pressure jet burner, which atomises and ignites the fuel in a combustion chamber. Beyond that shared principle, the choice that matters is the boiler configuration.
A regular (heat-only) boiler is the most common domestic arrangement, working with a hot water cylinder and often a cold water tank — straightforward to service and repair, and the usual choice when replacing an existing regular boiler and system. A system boiler feeds a cylinder without a cold water tank, giving mains-pressure hot water where more than one bathroom draws simultaneously. A condensing boiler recovers heat from the flue gases before they leave the building, giving a genuine efficiency improvement and is now the standard specification for new installations.
Regular, system and condensing configurations, each suited to a different property
Room-sealed or open-flued arrangement confirmed against the property
Configuration confirmed against existing pipework, hot water demand and flue route — not a default like-for-like swap
Condensing replacement is usually the single biggest efficiency gain available on an oil system
Reviews from real ComGas customers, shown as submitted through Google.
Posted on Google
Lucie Victoria
15 May 2025
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Excellent service, highly recommend
Posted on Google
James Mowat
30 April 2025
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Incredible service — problems fixed perfectly once again.
Lee, Paul and the team at COMGAS are fantastic. They arrived on time and got straight to work, quickly identifying the root cause of the plumbing and heating issues I was experiencing.
The problems were diagnosed swiftly, I was kept fully informed throughout, and both issues were fixed with impressive speed and precision.
Having worked in the industry for nearly 20 years, I know how rare it is to find reliable, trustworthy, and genuinely skilled professionals — let alone a team this good.
I joked about it at the time, but it’s true: I had the best shower I’ve ever had in this house after they finished the job — and I’ve lived here for 10 years!
I honestly couldn’t ask for more and can’t recommend COMGAS highly enough.
Posted on Google
Faz
31 March 2025
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ComGas replaced my boiler and water tank at short notice. So glad i used them. Thank you
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Laura Andrews
26 March 2025
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Lee came out to the school I work in to look at a problem with our heating, he diagnosed the issue and was able to fix it on the spot in a neat and tidy manor. Would highly recommend
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Chloe
26 March 2025
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I recently used Comgas for a gas and heating service, and I couldn't be more impressed! From start to finish, their team was professional, friendly, and highly knowledgeable. They quickly identified the issue with my heating system and explained everything in detail, offering both short- and long-term solutions.
The technician was punctual and took extra care to ensure everything was running smoothly. I really appreciated their attention to detail and how they made sure to clean up after the work was completed. My home is now warm and cozy, all thanks to their expert service. I highly recommend Comgas for anyone looking for reliable, efficient, and trustworthy gas and heating professionals!
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Bec Newey
8 July 2024
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Messaged Lee on a Sunday evening with request. Instant reply that evening and engineer came next day. Polite, professional and helpful. Thorough investigation and speedy resolution to a leak with sink in wc. Happy customer.
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P Duffy
2 April 2024
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Scott and the team have served me well over several years. Skilled craftsmen. Dependable careful and very cosy-effective. I highly recommend them.
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Cilla Trout
22 March 2024
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Definitely recommend friendly reliable service
Scott was helpful and reassuring regarding our boiler answered our concerns and explained the problem and best course of action thank you for your advice
Oil heating questions
Frequently asked questions.
If your oil boiler has broken down or you're experiencing a fault, it should be booked as a diagnostic repair visit rather than waiting for a scheduled service.
Do I need an OFTEC-registered engineer for my oil boiler?
Yes. Oil-fired appliances fall outside Gas Safe registration and are instead covered by OFTEC, the recognised body for the oil heating industry. Installation, servicing and repair of a domestic oil boiler and its tank should always be carried out by an OFTEC-registered engineer.
How often should a domestic oil boiler be serviced?
Annually, in line with manufacturer guidance, to keep combustion efficient, reduce soot and residue build-up, and catch developing faults — a worn nozzle or dirty photocell, for example — before they cause a breakdown in cold weather.
My oil boiler has broken down — can it be repaired, or does it need replacing?
It depends on the fault, the boiler's age and how it has performed previously. A single component failure on a boiler that has otherwise served well is usually worth repairing. Frequent breakdowns, an obsolete part, or a boiler that is clearly at the end of its working life point towards replacement. We give that assessment honestly at the point of diagnosis.
What are the rules on storing heating oil at my property?
Tanks need to be sited with appropriate separation from boundaries, buildings, openings and watercourses, and modern replacement tanks are typically bunded to provide secondary containment if the inner tank fails. We check an existing tank's siting and condition against current requirements whenever we work on the system, and advise on renewal where it falls short.
Is my oil boiler suitable for a rural or off-grid property with no mains gas?
Yes — this is precisely what oil heating is for. It is a well-established, reliable technology for properties without a realistic mains gas connection, common across the villages and outlying properties around Farnham, Guildford, Godalming, Farnborough, Fleet and Camberley.
Do you work on light commercial or multi-occupancy oil systems?
Our residential oil service covers single domestic dwellings and residential lettings. Larger, light commercial or multi-occupancy oil plant is covered separately.
Should I replace my oil boiler with a heat pump instead?
It depends on the property's insulation, existing radiators or underfloor circuits, and how the household uses heating and hot water. It's a genuine option worth assessing rather than assuming.
