Mixing hotwater and oil fed hotwater systems

[Eric]

I have a home that the heat and hotwater is done by a single oil furnace. Although I'm not interested in switching from oil to electric, I was thinking it might be an idea to complement the oil system with an electric system as a backup?

I was wondering if the idea of putting in an electric hot water tank inline with the output of the oilfed hotwater system would be a good idea or not? At this point, I'm only thinking about the hotwater used at the taps, not the heaters. The idea being that the water coming out of the furnace would be held in the tank, and kept hot by electricity. (although I'm thinking that electrical usage would be low do to the water entering being reasonably hot already.)

Essentially, just thinking in case of a failure on the oil furnace, that the hotwater tank would back me up?

Is this a reasable idea? Or should I spend my money on a different project? :)

Thanks!

[m Ransley]

It depends on your kwh rate. Only a few states have electrical costs near to that of gas. 0.12 kwh may be more than double the cost of gas

[Tom Accuosti]

The previous owners of my house hooked up a small electirc heater inline with the HW coming from the gas-fired water heater. The heater supplies directly to the 2 bathrooms, so the issue for them seemed to be getting hot water within seconds after turning on the shower, or perhaps supplementing the showers while washing dishes or clothes.

The house has forced warm air, so extra water for heating was not an issue. In fact, they even put in electric baseboards to supplement the gas furnace, or to possibly just warm one or two rooms instead of the entire house.

Tom

[HA HA Budys Here]

As a backup for what? If your goal is to keep a quantity of hot water in storage to accomodate periods of higher than normal usage, you could do that without even hooking up the Electric WH to a power source. Simply pipe the hot output from the boiler to the cold input of the EWH, and the hot output from the EWH to both your hot water and a return line with a small circulator pump to the cold feed on the domestic coil of the boiler.

Use the EWH's thermostat to control the circulator pump.

If furnace failure is a concern, consider this. If it does fail it will require immediate replacement anyway, since you'd be without heat. What would you gain by having a tank of hot water standing by?

, >Is this a reasable idea? Or should I spend my money on a different