central heating combi boiler

Hi I wonder if anyone can help me . Our old combi boiler was replaced in December because the water jacket was leaking & could not be repaired [ Grant Boiler], soon after fitting the pressure dropped again, Engineers came & found a small leak.
One again the pressure is dropping, i am now told itmust be a leak in the house, probably under the floor boards & nothing to do with them . The problem did not exist before the new boiler was fitted
On top of that i have now also had an account for commissioning the boiler, this was not done at the time of fitting.
Could i question why a separate expensive trip was required for this, Thanks Wally
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.