So there you are, you have done all the research and checked all your options and you have bought your new combi boiler. Purchasing a new combi boiler is the easy part – once you have established which type is best suited for your needs and budget, then the new boiler can be with you in just a few days. But how to install it?

Which boiler?

The first decision to make is whether to choose the all-in-one purchase directly from the manufacturer or do you opt for a fitter separate from the retailer? The former will save time and effort, the latter may save you money and you have control over the selection of the engineer/installer. And what about if you want to install the combi boiler yourself. For some people this will sound like a nightmare scenario, but many people relish the challenge, the learning process, the sense of achievement that comes from completing this intricate piece of DIY work.

Making the right choice

Installing a combi boiler is not a simple task. In fact, it is a legal requirement that if you are installing a gas combi boiler, you MUST hire a Gas Safe engineer to do the work. Installing any combi boiler involves a lot more skill, time, technical knowledge and DIY confidence than many other home improvement tasks. Typically, installing a combi boiler will take a couple of full days’ work and there will be a lot of equipment lying around the house while you are doing the work. Be aware that you will be without heating while the work is being done, so ensure you are prepared and your family is aware of the implications of your endeavors.

Preparing for upheaval

Before you even begin, you may need to rip out the older storage-tank heating system, which can lead to dust, upheaval and old boiler parts all over the house. Suitably warned, you’re more or less ready to get started.

How To Install a Combi Boiler:

  • Know the law: There are a number of laws and regulations regarding combi boiler installation, including the Part P of the UK Building Regulations. These outline the best ways to avoid risks such as fire or physical injury and also reference more specific areas of concern such as how to handle electrical wiring.
  • Read your instructions manual: Read over the instruction manual thoroughly, making sure you know exactly what needs doing and in what order. It’s also a good idea to lay out and list all the materials before you begin too; count out the unit, flue, all the necessary copper-piping and new radiators.
  • Plan, plan, plan: Before installation, figure out where all your materials need to be placed; that includes a place for the boiler unit (which contains the hot water storage cylinder, pump, feed/expansion tanks and controls all in one); positioning your new radiators for optimum heat exposure and ensuring each item is surrounded by enough space for air circulation and follow-up maintenance.
  • Follow directions: If your project includes installing new radiators, you will need to map out your pipe routes. A colour-coded tape system could be useful here to define which pipe goes where. Your pipe routes will usually involve a two-pipe (parallel) system, which includes an initial flow-line and a secondary return pipe.
  • At the business end: Now for the real task, fitting your boiler to the wall and setting up all the necessary pipe work. Before you start, switch off all electrics and water. This task will obviously take the longest, and you cannot afford to rush it or cut corners. Everything must be exactly where it should be and is properly fitted and secured.
  • Bleeding radiators: If you have new radiators you will need to bleed them before they become operational. Bleeding involves turning the valve or key at the bottom of each radiator until a small amount of water spills over the top, catch this with a cloth.

With all home improvements, paying enough care and attention will mean that you are able to do a great job at a fraction of the cost of calling out the manufacturers to do the job for you. And then there is that great feeling of satisfaction with a job well done.