Replace my water holding tank?

[eichelman]

I have a 40 gallon galvanized tank that is rusting out and leaking, it holds water that comes in from the municipality, warms it to room temperature naturally, and then feeds the water into the oil boiler.

The oil boiler then heats the water and it goes into a 80 gallon electric water tank that appears in good condition.

Yeah, it was built by a contractor! So, a new tank is $240 plus labor, or I can just bypass the 40 gallon tank and not preheat the water that goes into the boiler to preheat the water into the water heater.

Which way would you do? Is there a cheaper place to get another type of tank, a plastic one?

Fred

[Bumblerazz]

I've never heard of using a pressure tank for that purpose. Interesting idea. Though I suppose if the tank is in the house then you're paying for the heating of the water anyways as it takes heat from the house you heat.

Personally, I wouldn't bother with the extra cost of the tank. As the tank is not a very efficient way of preheating, it would take a long time for it to pay for itself.

If you're sold on preheating the water, investigate a solar system. expensive but the ROI is around 4-6yrs, depending on usage.

[eichelman]

I just had my cousin cut out the tank, and leave the pipes in case I run across a free tank some day! ha!:laugh:

[AllanJ]

Maybe the tank is the pressure tank left over from a well water system that was changed over to municipal water.

The boiler may need an air filled tank of its own to maintain proper pressure.

A finned baseboard radiator core is quite suitable for preheating water going into a water heater except that the copper pipe in it is not rated for pressure of domestic water.

[scuba_dave]

I'm actually planning on doing the same thing at my house
Incoming water is close to freezing
Basement is around 60 degrees
If I can connect a holding tank that will allow more water to warm to 60 degrees in the winter, then the WH will only need to heat water from 60-120, instead of 32-120

I just need to figure out a decent tank that isn't that expensive
I don't really want another water heater

[Bumblerazz]

I think preheating the water is an excellent idea, but a holding tank really is an inefficient way of doing it. You would do better to wrap a coil of copper pipe around the chimney exhaust of your furnace or some other source of waste heat. A rad or coil of pipe would be much more efficient than just a tank, you need to maximize the surface area of the water exposed to the heat source, especially when you will be constantly using the water.

[scuba_dave]

I was thinking that the bulk of our water use is in the morning for showers. After that its unlikely we would use more then a few gallons at a time. Except for our sons bath at night

In the summer I want to use a solar heating system to heat the water in this tank. Still thinking about setup, so any & all ideas are good

[eichelman]

My old holding tank was next to my oil furnance, which at 85% efficient, means it kept that part of the basement not so cold. So the waste heat heats up a portion of our basement. So yeah, maybe the tank made the basement a little colder in winter, but not much. It seemed mostly free heat.

My plumber friend thought the water came in at 50 degrees by the way. I suppose I could test the cold water lines.

Fred