Dumb question about my oil fired boiler

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daveswoodhauler

Minister of Fire
May 20, 2008
1,847
Massachusetts
Ok, so I have an oil fired boiler (forced hot water) and one of those bladder type hanging things above the boiler for the hot water. (Expansion Tank?)
Anyway, I am looking to convert to an electric hot water heater (as I read a very good thread here on the results), as from June 6th to now we have burned about 70 gallons of oil for hot water only.
Is there a way they can just disconnect the current method of heating the hot water and just add on an electric hot water tank? Or is it part of the whole system, and there will be more modifications needed?
Again, I know nothing about plumbing.
 
On that setup there is usually a separate coil inside the boiler for your domestic hot water. I believe that you can remove the pipe going into that and connect that pipe to your water heater. Also the pipe coming out of the coil will need to be connected to the water heater outlet. You can tell which pipe is which be seeing where the pipes go. The supply will be coming from your meter or well and the other pipe will be going to your faucets. Good Luck
 
Not sure on the specifics of your water usage. Do you have a large family? If you calculate your oil usage, it equates to about $70/mo. @ $3.50/gallon. Not the greatest but you might end up increasing your electric bill by $30-$40/mo.

When was the last time your boiler was serviced? What about insulating your pipes?
 
SIERRADMAX said:
Not sure on the specifics of your water usage. Do you have a large family? If you calculate your oil usage, it equates to about $70/mo. @ $3.50/gallon. Not the greatest but you might end up increasing your electric bill by $30-$40/mo.

When was the last time your boiler was serviced? What about insulating your pipes?

Family of 5, 3 kids (all boys) ages 4 to 9. Wife and I don't take long showers, and during the fall/winter the kids just have baths every other night, unless they are really dirty lol.

Pipes are all insulated, and the boiler is serviced annually.

What I am trying to determine is how much harder the electric water tank is going to have to work in the winter...as the majority of our heat needs will be coming from the wood insert....I'm guessing that perhaps I will see a savings in the summer with the electric hot water heater, but perhaps not that much in the winter.
 
No need to remove the lines off the existing boiler. It should have a shutoff on the water line. Just turn it off. With your new electric water heater, get some t-fittings, and tap right in to the existing hot and cold lines.
 
Couple things to look at:

Does your hot water come from a tank that's fired from a boiler zone or through a coil in the boiler? If its a tankless coil that loops through the boiler then simply installing an electric hot water heater is not going to solve all your problems. A tankless coil is always found in a warm-start boiler, and depending on the type of boiler it may need to stay hot year round regardless of your hot water needs.

Also, if you disconnect the hot water lines from the coil and re-route them to the new electric HW tank make sure the old lines are not capped, or at the very least have some form of pressure release. Commonly, an electric HW heater will be put in series with the coil and not completely replace it.
 
btuser said:
Couple things to look at:

Does your hot water come from a tank that's fired from a boiler zone or through a coil in the boiler? If its a tankless coil that loops through the boiler then simply installing an electric hot water heater is not going to solve all your problems. A tankless coil is always found in a warm-start boiler, and depending on the type of boiler it may need to stay hot year round regardless of your hot water needs.

I think you hit the nail on the head BTU...the domestic hot water seems to come from right inside the boiler (coils I'm guessing) and then runs into a mixing valve, then off to the faucets, etc... The bladder type thingy appears to be tied into the piping that supplies the hot water to the registers, so I am guessing I have one of those warm start boilers.

Back to square one I guess....really hate hearing that boiler run year round...especially when its 2 am and 75 out and no one is home.
 
Depending on your electric rate you may want to still consider it. You can leave the boiler warm-start and just pull your hot water from the electric HW heater. Yes it may kick on once in a while during the day due to typical standby losses but nowhere near as much when you figure the loads asked of it during the day (people washing their hands, laundry, dishwasher ect). There's a tripple aquastat for the boiler control high/low limit and differential (this is an assumption that you don't have an outdoor reset or some fancy control). Right now they're probably set for 160/180 and 15diff. If you add the electric HW heater you can turn the low-limit down to 120 (if your seals can handle the adjustment) and the differential up to say, 20f. This will lower your standby losses considerably during the Summer months when the boiler isn't needed.

There is a simple way to convert a warm-start boiler to a cold-start HOWEVER, it often doesn't end well. After years of getting used to a certain temperature range seals and gaskets don't take kindly to the boiler suddenly cooling down to room temperature. I tried it at my house with a welded steel boiler and the flange gaskets started pissing all over the floor like a new puppy. It can be even worse with a cast iron model.
 
Thanks for the info BTU. After thinking of the cost to switch and minimal savings, I am guessing that I might put this on the back burner for a while..just doesn't seem to be worth the savings right now.
I do appreciate the info....thanks much to my neighbor to the north.
 
I have the same setup, don't get your concern--the boiler can run without the DHW coil being connected, its a separate loop. And if you can front the money for a HP hot water heater (and have a large air space to run it), it will cost less than half as much to run. When I crunched my numbers, payback was a few years.
 
daveswoodhauler said:
Family of 5, 3 kids (all boys) ages 4 to 9. Wife and I don't take long showers, and during the fall/winter the kids just have baths every other night, unless they are really dirty lol.

I can't advise about the heater, but I can tell you how this plays out, oh father-of-ages-4-to-9.

They go through their docile get-in-the-tub-when-told stage, which it sounds like you are blissfully enjoying unawares right now. Then comes the stinky stage, as in "Pwew, you stink, time for your weekly shower," (said from across the room with nose plugged). I used to just pour shampoo in my palm, and hide it behind my back, and rub it in their hair as they ran past if my instructions to bathe were ignored overlong. (Now *there's* a child-rearing tip you won't find just anywhere.) Then comes a delightful stage when they rediscover the joys of hygiene, and just when you think you've returned to bliss, you realize that the daily showers have morphed into twice daily showers, which start to stretch out to twenty minutes or longer, and then one day you go into the bathroom and discover you can't access the sink to brush your teeth because someone has moved your stereo system into the bathroom because they like to listen to music when they shower and you never listen to anything good on it, anyway.

The length of their showers is directly correlated to the cost of your water and your means of heating it.

Just sayin' . . .
 
Thanks for the info. Wish I had the coin for the Geospring...looks sweet...funds are tied up in Karate, Music Lessons and preschool, lol
Maybe I need a part time job too?
Snowleopard...your post was too funny....I'll touch abse with you in a few years and see if your predictions are true :)
 
one other thing to remember is that if they take their showers back to back someone will get a cold shower. the electric water heaters don't recover fast at all. they are the slowest of all the ways to get hot water. if you hookup the electric with the oil tankless coil so that the output side of the oil burner goes into the input side of the electric tank the oil will kick on the same amount of time because the cold water line is hook into the oil burner. the only way to do it is one way or the other. then shut of the service switch at the boiler for the summer if you use the electric.
 
fbelec said:
one other thing to remember is that if they take their showers back to back someone will get a cold shower. the electric water heaters don't recover fast at all. they are the slowest of all the ways to get hot water. if you hookup the electric with the oil tankless coil so that the output side of the oil burner goes into the input side of the electric tank the oil will kick on the same amount of time because the cold water line is hook into the oil burner. the only way to do it is one way or the other. then shut of the service switch at the boiler for the summer if you use the electric.

Thanks Frank...all good info. The demand time for my kids might rule us out for an electric unit. Sometimes we have 2 showers going at once with the kids, and when its bath night they all take baths showers in the span of an hour or so....recovery time just not be enough for us...so I appreaciate the info.
 
I ran the same idea past my plumber guy and he says ( with the electric rates here and tank efficiencies) oil can still be cheaper.
He did recommend I replace my old steel boiler as it is starting to leak and I'd cut my oil use by almost 25% a year. Go with a zone tank rather than coil inside.
There are fed /state rebates that help and Mass Save has some 0% 7 year loans .
Basically the savings from using less oil is going to the burner loan and the loan is paid off at about the same time .

I'm considering solar hot water but for right now I just want to get this old burner gone.
I like the Bruderus burner but I think it's overkill for my little house and will take too long to pay back.


Change to natural gas ?
 
Would like to change to Nat Gas, but its not in our area.....I'm kinda in the sticks I guess LOL.
Maybe when the boiler needs replacing I will look into a combo oil/wood unit....or something similar.
 
Just my experience and 2 cents: I have a high efficiency Buderus oil burner - keeps a tank full of hot water 24/7. I filled my tank last mid-October - 330 gallons. I'm just over 1/4 tank right now - only using the oil for DHW with 100% wood heat. I'm guessing I could go at least 400 days on 330 gallons, likely more, based on my usage. Assuming $4/gallon, at 400 days, I'd be at $3.30/day. Not bad. This is why I dropped the idea of switching to electric hot water - I had considered the move, but I just don't think the up front cost of the unit, install, etc. would make it worth the switch. Cheers!
 
btuser said:
Right now there's a super-sale for the Geosprings HP unit at Lowes. Coupled with a rebate you can definately save some money.

http://www.geappliances.com/heat-pump-hot-water-heater/

If you're basement isn't finished and you've got a enough room jump on this.

Yes I would highly recommend this.

I installed one in March.

My electric bill went up $15/month, so I'm paying about $0.50 a day for hot water. Much better than the indirect oil boiler setup I had before.
 
Huskyforlife said:
btuser said:
Right now there's a super-sale for the Geosprings HP unit at Lowes. Coupled with a rebate you can definately save some money.

http://www.geappliances.com/heat-pump-hot-water-heater/

If you're basement isn't finished and you've got a enough room jump on this.

Yes I would highly recommend this.

I installed one in March.

My electric bill went up $15/month, so I'm paying about $0.50 a day for hot water. Much better than the indirect oil boiler setup I had before.

Hmmmm......well, perhaps I should keep looking into this! Cheers!
 
having wired and programed a load of budarus boilers i can say they are very efficient. even tho they are cast iron from dead cold it starts throwing hot water out the pipe in 10 to 30 seconds. they somehow mix silicone in with their cast iron. the test them by heating to block up to 300 degrees then throwing in cold water. if it cracks, it's defective. that would kill just about every other boiler out on the market. and with the way the heat from the fuel travels thru the boiler it's fast in heating. the burn of oil may be 87% efficient but how fast the unit heat up makes all the difference on how much fuel it burns. but............ they have been having troubles with the piece that the smoke pipe attaches to. it has warped, cracked and creating problems with leaks. the company doesn't want to own up to it. so we have stopped doing the install of the budarus oil boilers. you can do a oil fired tank for your hot water. the oil guys use a company called bock. the burner goes directly into the bottom of the tank like a gas fired water heater. people that have them say it doesn't cost to much for their hot water with these tanks. but.........like gas fired units they last 5 to 8 years then the tank has to be replaced. but you get to use the same burner. if your interested i know a guy that wants to sell a tarm 140,000 btu wood/oil boiler for 2000.00. indoor boiler.
 
I would also be concerned about letting your boiler cool down for the summer after a life of holding heat. I'd almost guarantee leaks appearing.

I'd also consider (am, actually) plumbing in some solar panels - maybe check out incentives in your area for solar installs. Most areas have some, any solar installer/dealer should be able to tell you all about them - they are a key selling point.
 
Depending on what kind of boiler you have the cooling may not be a problem. Sectional cast irion would be a problem, welded steel boiler maybe not so much.
 
maple1 said:
I would also be concerned about letting your boiler cool down for the summer after a life of holding heat. I'd almost guarantee leaks appearing.

I'd also consider (am, actually) plumbing in some solar panels - maybe check out incentives in your area for solar installs. Most areas have some, any solar installer/dealer should be able to tell you all about them - they are a key selling point.

agree about leaks. that is why the old coal boiler that look like a snowman last so long. they are most of the time used for domestic hot water and are wired to stay warm. from what i'am told the rust goes from lite color to rotting type of rust below 140 degrees
 
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