Combi to combi
Same position, same pipes, new flue kit. Usually done in a day.
Combi boilers · Addiscombe CR0
Addiscombe’s terraces and semis are mostly on combis now, and the newer apartments near East Croydon have them too. Whether it’s a house or a flat with a managing agent, we’ll fit a new combi with the paperwork and parking sorted before the day.

Addiscombe homes
Just east of East Croydon station, Addiscombe is Victorian and Edwardian terraces and semis, plenty of flat conversions, and newer apartments near the station. In most of them the combi is already there, so a new one is a straight swap in the same position.
Some houses still have a regular boiler with tanks in the loft, and some older semis still have a back boiler. Those are bigger jobs. If that’s you, see back boiler replacement in Addiscombe or combi conversions. For everything else in the area, our Addiscombe page has the details, and combi boiler installation explains how combis work.
Which job is yours?
Same position, same pipes, new flue kit. Usually done in a day.
Often with a managing agent who wants to know about any work on the flue before it starts.
Tanks and cylinder out, mains-pressure hot water in, if the incoming flow is strong enough.
The fireplace boiler comes out and the new combi goes somewhere more useful, often the kitchen.
Apartments
The order that keeps managing agents happy and gets you a date.
For a like-for-like swap in the same position, permission usually isn’t needed, but leases vary. A new flue position often needs approval.
The boiler, the flue from inside, and the outside wall if you can see it. Many apartment combis can be priced from those.
Our company name, Gas Safe number 567789, insurance and what the work involves, ready to forward to your managing agent.
Once you have the go-ahead we fix a date, and let you know what we need for parking and building access.
Installation day
A like-for-like replacement is usually done in a day. Conversions and moving the boiler add a day or two, and we’ll tell you the plan in advance.



We protect floors and the route to the boiler, then isolate the gas, water and power.
The old boiler is drained and removed. If tanks or a cylinder are going too, they come out now.
The radiators and pipes are flushed so the new boiler starts on clean water.
The new boiler goes up with its flue, filter, condensate drain and controls, and the pipework is tidied.
Gas tightness and combustion are checked with an analyser, inhibitor is added and the flow temperature set for efficiency.
A walk-through of the boiler and controls, the Benchmark checklist handed over, and the warranty and Building Control paperwork underway.
Who you’re dealing with
Anyone working on gas in your home must be on the Gas Safe Register. It takes thirty seconds to check, and you should check whoever you use.
Registration number 567789. Required by law for anyone working on gas appliances.
Formally trained and qualified in plumbing and heating.
Public liability cover for work in your home.
A registered limited company, not a one-off trader. Your quote and paperwork come from the company.
Combi boiler installation nearby
FAQ
For a like-for-like swap in the same position, usually not, but leases vary. For a new flue position, often yes. We’ll give you the details to send them.
Often, yes. It takes out the tanks and cylinder and gives mains-pressure hot water. We measure your mains flow first, because a combi is only as good as the water coming in.
For a combi to combi swap, usually just the working day. Conversions from tanks or a back boiler take longer, and your quote says how long.
Yes, including Addiscombe, Shirley, Waddon and central Croydon. See also our Shirley page.
Every new boiler comes with a new flue kit. Whether it can go in the same position depends on today’s rules about windows, doors and boundaries. We check before we quote.
Guides
New boilers
Conversions
Repairs & servicing
House or apartment, start with the quote form. Photos of the boiler and flue help us price it.