ComGas designs and installs wet underfloor heating for new builds, extensions and retrofits across Farnham, Guildford, Godalming, Farnborough, Fleet and Camberley. Systems are sized to the floor construction and heat loss of the room, not fitted to a standard spacing regardless of build-up, and commissioned with the manifold correctly balanced before handover.
Underfloor heating splits into two genuinely different systems, and the choice matters more than it looks. Electric (dry) underfloor heating is a resistive heating mat run directly off the electricity supply — quick to fit, but expensive to run continuously and generally only sensible for a single small room, such as a bathroom, where it supplements another heat source.
Wet underfloor heating circulates warm water through pipe loops fed from your boiler or heat pump, in the same way radiators do, and is the system used to heat whole rooms or whole floors efficiently. We focus on wet systems because that's what genuinely replaces or extends a home's primary heating, rather than adding a comfort feature to one room. Where a single small area is the actual requirement, we'll say so and scope it honestly rather than selling a whole-house system unnecessarily.
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How we design and install underfloor heating
Every system matched to floor build-up, covering and use.
The floor construction, covering and heat loss of each room decide which underfloor heating system applies, how it is zoned and controlled, and how it should be commissioned.
Screed, Low-Profile and Joisted Floor Systems
The floor construction determines which underfloor heating system is actually possible, and this is decided before anything else. We assess the actual floor before recommending which system applies.
Screed systems: pipework set into a liquid screed poured over insulation, most common in new-build ground floors
Low-profile retrofit systems: thin panel or overlay systems fitted without raising floor height significantly
Joisted floor systems: pipework run between or below joists with aluminium spreader plates, used on suspended timber floors
Each system has a different response time, heat output ceiling and disruption profile during installation
Every wet underfloor heating installation is fed from a manifold, with each room or zone controlled independently so it can respond to its own demand rather than heating the whole floor as one block.
Manifold splits flow into individual pipe loops and balances flow rate per zone
Each zone controlled by a room thermostat operating an electric actuator on the manifold
Screed floors run best on a stable target temperature with weather compensation rather than frequent on/off cycling
Low-profile and joisted systems respond faster and tolerate a more conventional thermostat schedule
Underfloor heating typically runs at 35–45°C flow temperature, lower than radiators, suiting condensing boilers and heat pumps
The finished floor covering and the insulation beneath the pipework both have a direct effect on how well underfloor heating performs, so both are checked before the design is finalised.
Tile and stone have low thermal resistance and are close to ideal for underfloor heating
Engineered wood performs well within manufacturer limits
Thick carpet and underlay insulate against the heat and can push the required flow temperature up
Ground floors insulated to current Building Regulations as a minimum; existing solid floors assessed before a system is designed around them
Heat loss calculated per room using the actual insulation level, not an assumed one
A system that has been laid correctly can still underperform if it isn't commissioned properly, so every installation is balanced and checked before handover.
Flow rate balanced to each loop at the manifold so longer or larger loops receive proportionally more flow
Every zone actuator checked for correct response to its thermostat
Flow temperature set appropriately for the floor construction and covering
Commissioning record kept as part of the property's documentation
Lower flow temperatures are why underfloor heating suits heat pumps and condensing boilers.
Underfloor heating operates at a much lower flow temperature than radiators — typically in the region of 35–45°C rather than the 60–70°C radiators are often set to. That lower temperature is precisely the condition condensing boilers and heat pumps are most efficient at, because both extract more useful heat from the same fuel or electricity input when returning water is cooler. This is one of the strongest technical reasons to specify underfloor heating alongside a heat pump, since the system operates well inside the flow temperatures a heat pump can sustain efficiently, rather than forcing it toward the higher output radiators sometimes demand.
The floor's thermal mass governs how quickly a room responds to a change in demand. A screed floor heats and cools slowly and is best controlled with a stable target temperature and weather compensation rather than frequent on/off cycling, which it can't respond to quickly enough to be efficient. Low-profile and joisted systems have less thermal mass, respond faster, and tolerate a more conventional thermostat schedule. Getting the control strategy wrong for the floor type is a common reason underfloor heating gets a reputation for feeling sluggish or inconsistent — it's a design and settings issue, not a fault with the technology itself.
Flow temperatures typically 35–45°C, well inside efficient heat pump and condensing boiler operation
Screed floors: stable target temperature and weather compensation, not frequent on/off cycling
Low-profile and joisted floors: faster response, conventional thermostat schedule
Heat pump sizing and running costs are covered separately on our renewable energy page
Reviews from real ComGas customers, shown as submitted through Google.
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Lucie Victoria
15 May 2025
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Excellent service, highly recommend
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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.
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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
Underfloor heating questions
Frequently asked questions.
If you're planning underfloor heating alongside a heat pump, a renovation or a wider central heating change, get in touch and we'll design the system around your floor and your rooms.
Is underfloor heating more efficient than radiators?
It can be, mainly because it operates at a lower flow temperature that suits condensing boilers and heat pumps well, and because it heats a room evenly rather than from one or two hot points. The efficiency case depends on correct design — insulation, floor covering and flow temperature all matter — rather than being automatic.
Can I retrofit underfloor heating into an existing house without lifting every floor?
Often, yes, using low-profile systems for solid ground floors or joisted systems for suspended timber floors, both designed to avoid a full screed pour. The practical approach depends on your specific floor build-up, which we assess before proposing a system.
Does carpet stop underfloor heating from working?
Not entirely, but thick carpet and underlay reduce how effectively heat passes through the floor, and can require a higher flow temperature to compensate — which works against the efficiency benefit of the system. We check your intended floor coverings and design around an acceptable thermal resistance.
Can underfloor heating run alongside radiators in the same house?
Yes, this is common — underfloor heating downstairs with radiators upstairs, for example — provided the manifold and zoning are designed to allow the two circuits to run at their own appropriate flow temperatures rather than one compromising the other.
How long does underfloor heating take to warm up?
It depends on the floor type. Screed floors have high thermal mass and respond slowly but hold heat well, so they're best left running to a stable schedule. Low-profile and joisted systems respond faster and behave more like a conventional heating system.
Do you install electric underfloor heating too?
We focus on wet underfloor heating because it's the system that genuinely replaces or extends whole-room heating and pairs properly with a boiler or heat pump. For a single small area such as a bathroom floor, a simple electric mat may be the more proportionate option, and we'll advise honestly where that's the case.
Does underfloor heating work well with a heat pump?
Yes, and it's one of the better heat emitter choices for a heat pump because of the lower flow temperatures both operate at efficiently. Get in touch if you're specifying the two together and we'll design the underfloor system around the heat pump's expected output.
