I had a repairman at one of my properties the other day to look at a gas wall heater. 

I had a repairman come out to give me an estimate on the repair. 

The biggest problem was that she saw smoke coming from the rear of the electric oven and that ultimately claimed the life of the oven.I called a 24/7 electrician, he determined the issue was outside the home, and the power company's repairman quickly spotted the issue atop a pole leading the power to the house.

We bought a park last year and I think I just bought a yacht for my furnace repairman...

More of a handshake agreement that the appliances will be operational, which in my experience they did honor when an oven stopped working in 3 weeks (they sent a repairman and replaced a part for free).  

I tried it for a couple months about a decade ago and I had a hard time getting people to work on my hvac when it went out because the repair man all said those kind of insurance makes it hard to colloect their money....this was american home shield and at that time they said I could use any repairman....meanwhile i have a tenant with kids burning up in the house in the middle of summer....so i just dropped them. 

What you need to remember is sometimes owners get charged trip charges or they have to pay  when sending/calling  a repairman out.

Foundation repairman here, and as a Repair Man, I have failed at my job if I left a home in worse shape then I found it.  

That means you need to start getting referrals for repairman.  

I want to network with a local repairman and potentially get them setup on some sort of CRM / work order system.