Have you checked to see if you can just replace the elements or the thermostat on the existing water heater?

A heating thermostat has a differential; the temperature difference between beginning and end of cycle.

Simply set the thermostat to emergency heat, and you have heat, which tides you over till the hvac guy gets there. 

If I did I'd do 220 hardwired with thermostat and would have to run a dedicated line.

I don't think you can kill one of these, it's a gas line, to a valve, with a thermostat and a cast iron burner that will last 100 years easily.

Anish Tolia ,While your right, they don't cost much, usually $40 to $80 depending on the size, but these costs were incurred BEFORE the property was placed into service, and the baseboard heaters and thermostats ended up around $450.So, according to the IRS, it must be added to the cost basis of the property, which is fine, but at what depreciation schedule?

hi all the factsit is 105 today tennant complains that her thermostat is set at 77deg and the air runs all day and only gets to 80 ,, she is a wuss if you ask me but she has small kids so okthe air con guy was called last time it was 105 and he topped it off the freon and said it was working fine and to drop the temp 25 deg was just about the max one could expect a unit to doso do i just tell her thats whats up it gets hot deal with it ,,any ideasthey pay the rent on time and keep the place nice but im not shelling out 5k for a new unit for her so she can get that 3 deg she is after

Where the cutoff is depends on age of heat pump and thermostat being used.

The 4 unit is heated by one furnace, controlled by one thermostat in one apartment. 

On a lot of the ones I manage we have blocked off the vents to one unit and put in electric baseboard heat with individual thermostats for each room so that both units can pay their own heat.