Moving combi boiler in attic

For a competent engineer with sufficient experience and knowledge, this isn't a mammoth of a task.
The fact the location of the new boiler is situated directly above where the previous boiler was located this makes running all the required pipes to there new required location so much easier. From the job description provided it states the system in place is already a combination system this eliminates any need for the system to require any conversions, for example removing any central heating or cold water storage tanks from the attic, plus no removal of hot water storage tanks ( Copper Storage tanks)......regarding the back boiler, from experience, I would presume that there is a high possibility that the back boiler wont be connected to the current system as back boilers where designed to provide a source of heat for old central heating systems basically it was the boiler as we know to be a wall hung or floor standing appliance, at one time they would be located behind your fire..depending on the customer's wishes concerning the back boiler if they wish for........the appliance to be removed or any other ideas they may have I would be able to answer these quaries during further inspection by means of an on site visit visual inspection to the property........concerning water pressure to the property we have access to information provided by all manufacturers of the boilers we install.......specifically stating the precise requirements concerning water pressures, required flow rates also covering pressures and flow rates for gas, so before we install the appliance we know we are able to provide the essential services that the appliance in question ( Combi Boiler) requires to operate Safely Efficiently and to the best of its ability.

We have special test equipment for testing gas pressures, and incoming water pressures to a property.
Once we have carried out the required tests we will know if there is any work needed to bring the water and gas to the required levels

As far as pipes leaking there is a possibility but it's all about preparation and control of the water in the property.

To be safe I would access, reveal the current pipeline of the cold water mains as much as practically possible may require some floor lifting etc but better to be safe than sorry,
Once access had been made and pipework upgraded, the whole pipeline existing pipes and newly installed pipelines I would put in place sufficient protection to the area floor covering etc making sure I could access any pipes joints etc we will test the pipes having a water vacuum floor covering and other means of catching g water, we think hard work easy this way any problems can be accessed and more importantly controlled at all times