Useful photographs can make an initial boiler quotation much more accurate. Send a clear front view of the existing boiler, the pipework directly beneath or around it, the flue position and the surrounding cupboard or wall so access can be understood.
Also include photographs of the thermostat or programmer, any hot-water cylinder if you have one, and anything unusual such as external pipework, a difficult loft location or a proposed new boiler position. Alongside the photos, provide the postcode, property type, number of bathrooms and a short description of any current faults.
Doherty's website specifically asks for boiler, control and visible-pipework photographs before the survey. For Glasgow replacements, that information helps establish whether the job looks like a standard package or may involve relocation or additional system work.
