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.
Posted on Google
Ricky Matthews
5 October 2026
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I'm the site Manager at St Paul's primary school and we have used ComGas for a whole refit of our water pipes. They was brilliant excellent friendly team never left a mess and the pipe work is so neat and tidy very professional work. We Also had an issue with our school Kitchen gas interlock system I called on Thursday morning they was there checking it over and parts ordered and fixed by Monday morning definitely recommend this company for any of your works especially in schools.
Posted on Google
steve brown
5 October 2026
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Comgas fit our central heating system six years ago and made a fantastic job of it .They have serviced it regularly every year ever since .
Matt has done the last two services for us and he is very thorough, he rectified a couple of small issues with the rads and is always pleasant and informative. He advices us of what he’s done and what he thinks will be required on our next years service.
We are happy to continue with their services and have found all the guys to be reliable and trustworthy.
Posted on Google
Julia Walker
30 September 2026
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Paul Pharo turned up on an emergency,within minutes he gave us so much reassurance to a burst hot water pipe isolated went and got new parts and had the penthouse back up with hot water with minimal damage..
can’t thank him enough and the company Comgas
Posted on Google
Ian Chevalier
30 September 2026
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First time we've used this company and it won't be the last. Very professional and efficient in everything they do and Matt was excellent in his knowledge and efficiency when dealing with our gas and plumbing problems.
Posted on Google
Kerryann Wood
25 September 2026
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Really happy with the service! Matt came out to carry out our boiler service and was friendly, professional and did a great job. The office team were also lovely and really helpful when arranging everything. Would definitely recommend and use them again. Thank you!
Posted on Google
Rob Haynes
14 September 2026
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Great service and the work completed in good time and professional company
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Ian Melville
11 September 2026
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Boiler service today engineer Matt on site, again great job very thorough clean and polite would recommend Comgas very professional outfit lovely staff. 👍🛠
Posted on Google
Bazmac
8 September 2026
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We use Comgas for our gas and water and Matt does a monthly check on the systems.
Always a pleasure do deal with.
Chloe in their office is really helpful with all enquiries
Barry
Nower House
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Lynn Brooks
8 September 2026
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Highly recommend. I think the engineers name was Matt, came to service my boiler, friendly and got on with the job quickly and efficiently.
Rated 5.0 out of 5 from 75 Google reviews.
"Really happy with the service! Matt came out to carry out our boiler service and was friendly, professional and did a great job."
Kerryann, Google review, September 2026
"First time we've used this company and it won't be the last. Very professional and efficient in everything they do…"
Ian, Google review, June 2026
"…ended up coming to my place of work and sorting an old heating system that hadn't worked for years in a car showroom & workshop. Great team of guys"
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.
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