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Gas, Oil or LPG Boiler

The first question you will have to answer is whether you are looking for a Combi boiler or standard boiler and hot water cylinder.

For more information on boiler types click here

Once you know the type of system that would suit your needs best it is time to get at least 3 quotes.

You can find installer details either by clicking here or by visiting the Gas Safe website. It is often best to choose a local installer in order to reduce travel costs, or a large firm who can get bulk discounts on boilers. However the most important thing is that the installer you call is Gas Safe registered, a member of a Competent Persons Scheme and if possible a Benchmark member.

Quotations, whether for a new heating installation, an extension to an existing system or a replacement system, should give information about the design and the materials to be used and should d be fully detailed so that you have no doubt about the work included. The price and conditions of trading should be stated, together with a full description of the work to be undertaken.

Any additional work necessary to enable the installation to be carried out or the system operate, but which has not been included in the quotation should also be clearly stated.

Click here for a list of the minimum technical information to be included in a specification.

Once your new system has been installed you should receive the following handover:

System Operation Explained

The system should be fully operated and shown to work satisfactorily.

The winter and summer operation of the system and the controls should be clearly explained, with particular attention given to showing you how the various controls work and how you can adjust them.

You should also be shown how to light the boiler (if applicable) and shown the location of the fuel shut-off valves and electrical fuses.

You should be given the correct instructions for venting the system and how to re-balance the circuits in case you have to remove the radiators (like for decoration).

Safety Instructions

You should have the full safety instructions explained to you, like the fact that air supply and fluing equipment must not be interfered with.

Written Instructions

A full written set of instructions should be passed on to, these should explain the operation of the full system including controls, along with manufacturer’s instructions.


All guarantee cards should be filled out and returned and all applicable guarantees and warranties explained to you.


The Benchmark Commissioning Checklist should have been completed. This is normally found in the manufacturer’s instructions. In some circumstances it may be called a log book.

This should be signed by you, this confirms that the installer has completed the installation correctly and commissioned it following the manufacturer’s instructions.

You should keep hold of these documents and ensure they are updated at each service interval.

Click here for more information on the benchmark scheme

Special Tools

At least 2 air vent keys, 2 fuses and any operating tools and spares that were supplied with the installed equipment should be handed over.


You should have your entire system serviced once a year by a qualified heating engineer. However maintaining the boiler and heating system will make sure that it runs as efficiently as possible. This should include:


Cleaning a heating system which has a build up of materials and/or limescale will significantly improve the efficiency of the system. There are three main treatments which can be applied, although customer should check with manufacturer if a particular boiler is suitable for particular treatments:

  • Flushing: This will either involve a ‘powerflush’, or a mains pressure water flush (which will take longer).
  • Inhibitors: Chemical inhibitors can be added to the system which helps prevent build up.
  • Water softeners: If a combi boiler is installed in a hard water area, water softeners can be added to the system.

A system may benefit from cleaning:

  • If a system is ‘cold-spotting’ – where the radiators do not provide uniform heat and feel cold to the touch in patches.
  • When the system pump can be heard ‘labouring’ – because the system is pumping round not just water, but also the build up.

When the boiler is serviced, check with the heating engineer that the system is clean. However, the system should not need cleaning annually

When a new boiler is installed the system should be completely flushed and drained and a chemical inhibitor added to reduce lime scaling and corrosion.

Bleeding Radiators

If the radiator is cold at the top and warm at the bottom, it probably needs ‘bleeding’. ‘Bleeding’ means to release the trapped air from inside the heating system. It will improve the flow of hot water inside the radiator and give a more even temperature. A key is needed to fit in the top side of the radiator, these are available to buy from DIY or hardware stores.