Yes. They also must be registered with Trustmark first.
For heat pumps (ground-, air- and water-source), solar thermal (liquid-filled flat plate or evacuated tube collectors) and biomass boilers, the installer should also be MCS certified.
Under Trustmark rules all installers have to operate to PAS 2030:2017, 2030:2019 or PAS 2035:2019 standards.
All installers working on insulating park homes MUST HAVE Trustmark registration under PAS2030:2019 part B13 : Park Home Insulation Installer and follow PAS2035 standards
(At present CIGA is the only Trustmark Scheme Provider that is providing Trustmark Registration for Park Homes Insulation Installers.)