Gas Safe registered 25 years in the trade 12 years running the business
What a combi boiler is
A combination boiler does two jobs in one box. It heats your radiators, and it heats water for your taps and shower the moment you turn them on, drawing straight from the cold mains. There is no hot water cylinder to store water, no cold tank in the loft and no waiting for a tank to warm up. When the hot tap closes, the boiler goes back to heating the house.
That makes a combi a good fit for a lot of homes in this part of South Wales: flats, terraced houses and semis with one bathroom, where usually only one person is showering at a time. Freeing up the airing cupboard and the loft is a welcome bonus in smaller properties. Where a combi struggles is in a busy house with two or three bathrooms in use at once, because the flow is shared between every open tap. Our combi vs system boiler guide goes through that decision in more detail.
Replacing a combi or converting to one
Swapping an old combi for a new one is the most common job we quote for. The gas, water and heating connections are usually already in roughly the right place, so the work tends to be the simplest kind of replacement. Chris still checks the flue, the condensate route and the gas pipe size, because a newer boiler may need a larger gas supply than the one it replaces.
Converting from a system boiler with a cylinder, or from a regular boiler with tanks in the loft, is a bigger job. The cylinder and any tanks come out, the pipework that fed them is capped off or removed, and the hot water pipes are reconnected to run from the new boiler. Your water pressure and flow are checked first, since a combi depends entirely on what comes in from the mains. If a conversion would leave you with weaker showers than you have now, Chris will say so and suggest keeping a cylinder with a system boiler installation instead.
Sizing a combi to your hot water use
Combi boilers are sold in different outputs, and for a combi the output mostly decides how quickly it can heat water flowing through it. A larger output gives a stronger, hotter shower in winter, when the incoming water is at its coldest. Going bigger than you need, though, simply adds cost without any real benefit.
To size it properly, Chris asks how many people live in the house, how many bathrooms and showers you have, whether you have a bath that you fill often, and what the mains flow is like at your kitchen tap. Those answers, together with the heat needed for your radiators, point to a sensible output. The new boiler cost guide explains how boiler size and model affect what you pay.
What a C Gill combi installation involves
Every installation is carried out by Chris and his son, a second-year apprentice. Chris has 25 years in the trade and has run C Gill Plumbing & Heating for the last 12; we are Gas Safe registered and family-run, and boiler installation is the main work we do.
It starts with a free, no-obligation survey at your home. Chris then gives you a written quote that lists what is included, so you can compare it fairly with any others. On the agreed day we protect the work area, take out the old boiler and remove it from site, fit and connect the new combi, test it and set up the controls. We finish by showing you how to use it and what the pressure gauge should read. Read about our wider approach on the boiler installation page.
Free home survey before any quote
Old boiler removed and taken away
Gas, flue and condensate checked
Controls set up and explained at handover
Where we fit combi boilers
We work from 65 Church Street in Briton Ferry and cover roughly 30 miles of SA11 2JG, taking in Neath, Port Talbot, Swansea, Bridgend and Llanelli. Swansea homeowners can read more on our boiler installation in Swansea page. Our hours are Monday to Friday 8am to 8pm and Saturday 8am to 6pm.
Get a combi boiler quote
Ring Chris on 07429 632804, send a WhatsApp with a photo of your current boiler, or fill in the form on our contact page. Tell us your postcode and how many bathrooms you have, and we will arrange a time to survey.
Common questions
Combi Boiler Installation FAQs
Clear answers before you arrange a visit.
Is a combi boiler right for my house?+
A combi usually suits homes with one bathroom where one shower runs at a time. Larger households with several bathrooms may be better served by a cylinder. Chris checks this on the survey.
Can you convert my system boiler to a combi?+
Often, yes. The cylinder comes out and the hot water pipes are reconnected to the new boiler. We check your mains pressure and flow first to make sure the change will work well.
How long does a combi swap take?+
It depends on the job. Conversions take longer than a like-for-like swap, and Chris will confirm how long your installation will take when he quotes.
Will I need new radiators?+
Not usually. Most existing radiators can stay. If any are leaking, undersized or badly corroded, Chris will point it out during the survey.
Do you take away the old boiler?+
Yes. Removing and taking away the old boiler is part of the installation.
