Not a lawyer but I don't think home repairs void most home insurances in common law countries unless you are working with parts that are particularly dangerous, part of a safety system to protect others, and/or absolutely require a skilled professional.
I'm pretty sure that if a fire starts in my central vacuum unit, and my insurance company does an investigation that finds a DIY swap of power electronics components in that unit, I would at the very least be in a lengthy legal battle to get any money back.
