Maybe they want a stove with a power burner.Different burners have different BTU's--maybe they are using the simmer burner vs the power burner--if the stove has one.Did install one of these, that work well with only one type of cookware (???) 

A 5% vacancy is  the same as 1 turnover every 20 months. 5/100=1/20. 4units*$1000=$4000/20 months = $200 per month and that doesn't cover clogged toilets, broken burner or leaky faucets.

But putting that question on the back burner for now, here's the scenario I'm considering: If I do choose to rent it out, I have some work I'd like to do on it, including a bathroom renovation and tiling in the kitchen.

Make sure you have a fat bank account for when things sink.  

So while I may not have a fat bank account I do have some money tied up in my properties and want to know how to put it to work for me.My question to you fine people is how do I free up that capital?

So while I may not have a fat bank account I do have some money tied up in my properties and want to know how to put it to work for me.I know quite a bit about buildings and work well with people however I could certainly use some coaching in leveraging and finding deals.

All 3 water heaters are electric and toward the end of their usable life. scenario 1: Total $19,4001 new gas boiler, $6K2 gas burners to use on existing boilers, $6K3 new water heaters, $3,600chimney liner, repair, waterproofing etc, $3,800 scenario 2: Total $17,6253 new high efficiency wall mounted combi units $16,500chimney work $1,125I'd appreciate any insight regarding this process, the high efficiency units, maintenance, reliability, availability of parts, ease of use and repair or if there are any other alternatives I should be considering. 

What repairs will be done(clogged toilet, burner not working, hvac service, etc).

They like big fat insurance policies.

All 3 water heaters are electric and toward the end of their usable life. scenario 1: Total $19,4001 new gas boiler, $6K2 gas burners to use on existing boilers, $6K3 new water heaters, $3,600chimney liner, repair, waterproofing etc, $3,800 scenario 2: Total $17,6253 new high efficiency wall mounted combi units $16,500chimney work $1,125I'd appreciate any insight regarding this process, the high efficiency units, maintenance, reliability, availability of parts, ease of use and repair or if there are any other alternatives I should be considering.