Attempt to save oil

[Claude Hopper]

I have hot water off my boiler so it's on all summer running a couple minutes several times a day weather I use hot water or not. I'm thinking of putting in a 20 gallon electric hot water heater and shutting down the boiler for the summers. Would I save much? My boiler is very efficient. I was also thinking alternatively , putting point of use electrics. These are small 120 volt, 29 amp demand water heaters for $149.00 each. One under the kitchen sink and one under the bathroom sink/shower feed. Better than a storage tank of hot water? Since the boiler and hot water tank run weather hot water is used or not verses the point of use heaters that only run when you are actually using water, might be the best choice?

[terry]

Yeah. Having the boiler cut in a few times a day just to reheat the water in the storage tank must be very inefficient.

Even before oil got so expensive recently there were a few people adding an electric tank heater so they could shut off their furnace almost entirely; although even some summer months here require some heat.

An electric tank, of say 40 gallons or even smaller comes to mind. Costing here around $225 - $250, plus pressure relief valve, 'electrical hook up etc, which even if you do it yourself is probably another $50 for bits and pieces of plumbing and wiring etc. you are probably looking at around $350 plus dollars.

Whether (not weather) that cost plus the cost of the small amount of electricity (depending on cost in your area) used to heat the water, minus any significant saving of oil, any change in amount of usage and maintenance of your oil furnace presumably being a neglible cost; would be worthwhile might be doubtful?

For convenience yes add/replace with electric. But make sure electric is big enough for family usage. As an economical cost saving probably not? Eventual change in wear and tear of furnace/boiler very slight?

[Claude Hopper]

No opinion on tankless point of use demand water heaters?

[ransley]

What do you use in oil in summer in gallons. What is your electric rate. A tankless is rated at gpm and a certain temp rise, so you must know incomming water temp, how much your shower needs in gpm and the temp you need for a shower, in winter water incomming goes down. a 29a tankless is not much and might restrict you to a super low flow shower head and a cool temp. In summer it might work, but winter is the issue when you will need a hotter shower. In summer I am able to reduce water temp by 10f and get a good shower. But a point of use has an advantage of very little temp loss to the shower head. Research it fully before you buy one, you need full voltage to get full power.

[PanHandler]

What do you use in oil in summer in gallons. What is your electric rate. A tankless is rated at gpm and a certain temp rise, so you must know incomming water temp,

snip

incoming, not incomming

[Jim Elbrecht]

-snip-

I doubt it would be worthwhile- but you need to answer a few questions for yourself.

1. how much oil do you use all summer.
2. how much is your oil.
3. How much is your electricity.
4. how much electricity will you use.
5. Will you be installing this stuff or paying a plumber & electrician.

Jim

[starrin]

I tried this after I put in a HWH in series between the boiler and the house, when the kids HW useage exceed the boiler's tankless heater's ability to keep up. With heat secured, this older cast iron boiler tended to develop leaks. I wound up setting the aquastat to the minimum setting I could. Boiler stayed warm and didn't leak. YMMV

[Uncle Monster]

With a tankless water heater you have to watch your rate of flow. I install them with ball valves on the input to adjust the rate of flow in gallons per minute. If your home has a pressure regulator like most homes,(some don't) the ball valve can be adjusted to give you a consistent flow rate. Some of the newer heaters handle high flow rates better than others. The higher your expected demand the more heating chambers your heater will need and the higher the electrical current requirement will be.

[8~{} Uncle Monster

[trader4]

It would seem it comes down to what we don't know, which is how many gallons of oil and the cost for hot water during the summer months. I would compare that to what you could expect to pay if you had a seperate water heater, either oil fired or electric. You could also use an electric tank water heater during summer, then switch back in winter. I would think that would be easier and simpler to install than multiple on demand electric units all over the house.

Also, the advice to go with a small water heater doesn't make any sense. The water heater needs to be sized as you would any water heater. It needs to be large enough to handle the typical worse case demand. That probably translates into a 40 to 50 gallon unit.

[Claude Hopper]

My flow rates are low since I'm on a well pump. Plus my shower runs at a trickle with throttling right at the shower head and is a super saver head.

[Claude Hopper]

I only need 2, one under the kitchen sink and one for the bathroom.

I got buy with a 20 gallon before in a mobile home. I live alone. No way do I want 40 or 50 gallons of preheated water hanging around.

[---MIKE---]

I only turn my boiler on when I need hot water. This averages about .4 gallons a day. In the early winter I tun the boiler off at night. Last year I used a total of 435 gallons of oil.

---MIKE---

[Claude Hopper]

I only used 100 gallons, I burn wood. But that's nearly $500!

[Bill]

The most savings in the long run will be a solar water heater backed up by an electric water heater.

[Joe]

This may be a dumb question but how do you turn off your boiler? Just flick the service switch? I thought of that a while ago then someone told me that was bad for the boiler is that true? I can't imagine how but they said it with a certain air of authority for which I am a sucker. What seems to be the best option would be a timer so the water could heat up in the morning for showers, do they make those?

[---MIKE---]

Joe asked:

I turn on the switch and leave it on until the tank reaches temperature. At that point the boiler turns off and I turn the switch off. This usually takes about 11 minutes. I have been doing this for 18 years so I don't think it's bad for the boiler. This procedure provides enough hot water for dishes and shaving. I leave it on longer for showers.

---MIKE---

[Claude Hopper]

So you don't have hot water in the evening if you want it. ( unless you start the boiler again).