Question about tankless water heating and boilers - help a chilly family!

[Dairy Godmother]

Hi everyone, forgive my cluelessness. We are first time homeowners in CT and I grew up in Southern Cal. So now I have this house with an oil-burning boiler set at about 180 (from what I've read this is not abnormal). It seemed fine until winter hit (and this one is a doozy) and now I'm lucky to get a lukewarm shower. Its a little better if I crank the heat for the house, but certainly not a hot shower. One plumber said we needed a hot water tank, but I'm unsure if this is wise to put in now if we are going to central heat and air this spring. Basically I'm loathe to spend a lot of money that we wont need in the future. Can one put in a hot water tank that works with the oil burning tankless/coil system and then later with a central, gas driven system? We actually have a gas line down there now coming into the basement if that makes a difference.

Any help very welcomed - I'm cranky without a hot bath!

[ransley]

is where boiler pros are. You have a coil in the boiler for HW? So fix it. its not leaking so it cant be that hard. You are changing from a boiler and radiators to a furnace and ducts, remove radiators? You need a few more opinions on that. I didnt we just added Spacepack. What is he paying you for your radiators!

[Marilyn & Bob]

The problem you are facing is that when the circulator pump goes on to bring hot water up to your radiators, it also brings down the cooler water that is in your system. This lowers the temperature of the heat exchanger in the tankless coil and therefore the temperature of your shower water. If you do not want to make an investment now, one thing you could do simply turn down the house thermostat to 50° a few minutes before you take the shower. This will shut off the circulation in the heating system and allow the boiler to heat the water in the tankless coil to near 180°. Don't forget to put the thermostat back to normal when you are finished with the shower or you will end up with hot water in a very cold house!!

Ultimately what you should have is a separate water heater, gas if you have it, electric if you don't. This will work independently of your heating system, whether boiler/radiator or furnace/fan. It will also be much cheaper to run in the non-heating season as you do not have to keep your boiler on just to make hot water.

(By the way, if you keep your current system with the tankless coil, you can use the output of the tankless coil to feed your water heater. Therefore when your boiler is running, you will be feeding warm--not ice cold--water into the heater and thus save a lot of cost of running the water heater).

[RBM]

It's pretty clear as to what you have currently, but not as clear as to what you are getting. You have a bad domestic coil running through the hot water jacket of the boiler currently and not producing enough hot water. This coil can be replaced or you could get an indirect hot water tank, which works off of the same boiler, as a separate zone and are very efficient. If you are replacing the boiler with a furnace and doing away with your hot water system altogether, you would want to get a gas, independent hot water tank, having no association with the oil burner that will be removed. If you are replacing the oil burner with a gas fired boiler, which could be incorporated into a new heating system via coils, (hydro-air), you could reconnect an indirect tank to that unit as well.

[Edwin Pawlowski]

Good chance that either the tankless coil is clogged or the mixing valve it not working In either case, fixing it and then replacing the entire unit later is a waste of money.

Short answer, yes you can put in an indirect fired tank and yes, it can be used later with the new system. Are you sticking with the hot water heat for the house?

I recently replaced by boiler with a new efficient oil boiler and indirect fired water tank. Works great and the first hour draw is over 200 gallons. I put in the Energy Kinetics System 2000. There are many efficient gas systems available too. Since you have a gas line already, a regular gas HW can be a good way to go.

Be sure to use the $500 rebate from the state. CT also has 100% financing at

0% interest for 10 years if you upgrade. I don't have the link here,but I can give it to you if you want it.

[Van Chocstraw]

If you put a small tankless point of use water heater to feed your tub it would be more than enough since the water is preheated by the boiler coil.

[Pete C.]

Yes, if you have gas service already, just install a standalone gas water heater now. If you are switching to a gas fired furnace / A/C setup it will require a separate water heater anyway since a furnace (heats air vs. a boiler heating water) does not provide for hot water. No money spent to add a separate gas water heater now will be wasted, and gas water heaters are pretty inexpensive anyway.

Having spent some 34 years in CT with an oil fired boiler and tankless DHW coil, I can tell you that if they are in reasonable condition they work just fine. Yours may be suffering from hard water scale buildup which will cut the heat transfer to the water in the coil.

[Bubba]

yeah ransley. A coil in the boiler for HW. I know thats hard for you to believe but its technology that been around for over 50 yrs now you dolt. Fix it. It cant be that hard. Sure ransley. Maybe a stick of chewing gum and some duct tape should do it. What is he paying for radiators? Leave it to you ransley to take that and make it something about you being a tight ass. What it costs to disconnect and carry those things down from the second floor and out of the house will negate any money they would make on selling the radiators you tightwad. Bubba

[HeyBub]

If you're going to replace your boiler with a furnace and A/C ducted system, won't you have to install a water heater anyway? I mean, your new gas furnace won't heat water... or will it? We don't have boilers in my part of the country...

[ransley]

Nobody diagnosed it. I know you dont have alot of boilers in your area, but friends I know regret previous owners were conned to going forced air. Where I am at -20f, radiators are quiet, hold heat and radiate for hours. Ive lived with all types of heat and forced air is not the same. Adding Space Pack is what is done in this above average town, junking a HW system, is what con artists do here. Reselling used radiators is big business in chicago, They cost alot, I have extra I wont sell. They are put in new construction and additions here. They work.

[Bubba]

"above average town" haha c'mon ransley. Everybody knows that as much as you squeak even a nice trailer is too expensive for your taste. There are boilers abound in this area.......even steam. Obviously, once again, you dont have a clue. Bubba

[trader4]

Wow, about time. That's exactly the solution. Since they're going to go to a gas furnace and AC soon, they will need a water heater anyway. Just put that it now. Problem solved. Of course the next issue will be whether it should be traditional or tankless. A little googling will produce plenty of threads on that topic.

[Dairy Godmother]

Just want to thank everyone for all the posts. It didnt click that something was wrong with what we had, but that it was just something people live with here (I know, not a very bright thought). I'm just sad we didnt figure it out during the home inspections! I think I"m going to have the boiler serviced to get the radiators all working (not sure if I mentioned that little problem) then have a hot water tank added with the gas line -- since it sounds like I can use it now (with boiler coil water) and later (if/when we get a central air heat system).

Funny to look up and realize you are one of those people you laugh at on TV -- who buy a house with 'charm' and have no idea how to take care of it!! Thanks everyone.

[Dairy Godmother]

OH..........that makes sense.

If you do

Wow, we had been doing the opposite with limited success -- thanks!

with the tankless coil, you can

That makes sense. I actually like the old cast iron radiators when they are working properly. Radiant heat feels a little kinder on the system than hot air blowing - we have enough of that ;-)

thanks BobJ

[Dairy Godmother]

Thats exactly what I wanted to hear. Thanks for understanding my rambling.

Great to know. I'd rather repair what I have than replace it all -- but I just didnt know if it was normal 9sounds dumb I know, as if the whole northeast was taking lukewarm baths)