Heat Plus Knowledge can be installed on the same Server as Heat Self Service
Heat Self Service and Heat Plus Knowledge can be installed on the same machine or server. There is no inherent conflict between these applications while running on the same server. The newer version of heat HSS and HPK use different web services, taking the burden away from Microsoft IIS service.
Just ensure the resources i.e. RAM, CPU, and storage space (C:\ partition) are sufficient for all of the services and number of users.
Please refer to Heat Installation guide.