New combi boiler existing pipework question

[bakedpitch]

I intend to replace my combi boiler with a new one. The existing gas/central heating pipes run under the floor and then are enclosed in the wall until they emerge underneath the boiler. I am being given conflicting information relating to these pipes. One party says new pipes will have to be rerouted to come through the floor and then run up outside the wall (inside the room) up to the new boiler. Another party said the existing pipes can remain inside the wall and simply connected to the new boiler.

Can anyone shed any light on this issue? Can I use the existing pipes or do I have to get new ones run up outside the wall?

 

[stevetheplumber]

if the heating works now it will work with the new boiler

 

[Clint 1979]

Unless you are having a larger boiler fitted due to extension (adding rads, bathroom, more demand for hot water), and the fitter needs to increase the gas pipe size, he may want to run it surface to save chasing wall out......other than that as steve said.