water heater or boiler for hydronic app?

joet

What is wrong with the steam system that you now buy pellets? I put a central pellet stove in because I was burning 250 gallon a month with steam. I'm leaning more toward Green these days, but not completely!

Do you like the radiant heat? I love warm tiles in the kitchen.

Water issues can be solved so xx that out for now.

I keep up with the water conditioners pretty well so its not really an issue, but I did bring it up if salts and Pt have affect on exchangers.

What are your goals? My local gas company has brought service to my house and is offering a 0% interest loan to convert from oil to a more efficient gas sourced heater.

Long term? I really don't plan on spending the next 25+ years in this house. more like 10

Short term? I think if I can get 120 degrees into the floor without burning the equivalent of 125 gallons of oil per month plus back up the main house on cold days, I'd be happy.

Does the steamer leak? Steam doesn't leak but does take some effort to balance.

joet

water heater or boiler for hydronic?

My radiant system was installed 10 years ago and utilizes an arm off my oil fired steam boiler with an exchanger for radiant heat in my kitchen.. Two years ago I installed a Harman pellet stove insert in our central fireplace which basically heats the main house. we use the steam as backup on cold cold days and for running the tankless hot water. I am now switching over to natural gas and have two proposals before me. One system is a Buderus boiler with a separate tank for DHW while the other is a Ruud hot water heater that will utilize my current heat exchanger for the radiant. One plumber estimates the Buderus will save me 30% more over oil because of its high efficiency plus the ability to run differnet temps based on outside temp. I don't have any idea how much better the Buderus savings is versus the std 40 gallon tank. Any comments?

As much as I'd like to get the highest efficiency, I'm faced with up front cost that is 3 grand different. Plus, as I consider this, I am only heating one room. (I live in a 1700s colonial that has wide pine plank floors & i don't think that radiant would work well with those old boards).

Are there any other water heat sources to consider? I read briefly about combination water heaters. I need to be careful in selecting a heater because I have a shallow well that has high Lime & mineral content in the water. Am I correct in steering clear of stainless steel tanks?

Alos heard from a guy who recs two Takagi tankless units? but I've read they don't really save too much....not sure

sorry if I'm all over the place here but this is a big decision for us and I don't have funds to overspend or have to redo/upgrade later.

thanx in advance

joet

anybody

Mark Custis

I am closing my first

day off in 12. I passed the first time I read this.

Here goes:

What is wrong with the steam system that you now buy pellets? Hats off bowing to Beth Page on the isle of long.

Do you like the radiant heat?

Water issues can be solved so xx that out for now.

What are your goals?

Long term?

Short term?

Does the steamer leak?

I like helping folks with big decisions, and I tend towards empowerment so that you know your choice is right.

I must return to the real world tomorrow so it might be a few hours until I return.

Charlie from wmass

Do you know a mega steam oil boiler can reach 86% AFUE? The buderus should save over a tank heater. I know water conditions can be fixed the issue I tend to have is people do not fix them or forget to maintain things such as softeners or neutralizers.

Jamie_5

still keeping back-up?

You say you use the steam system as a back-up on cold days. So do you need to have a heat source to supplement the pellet stove and radiant floor on some days? If so, what do you intend to use for that purpose?

Also, do you have any idea how much of a load demand your radiant kitchen will put on the heat source? If it is relatively small, it seems expensive to buy a boiler just for it rather than using a heat exchanger off the water heater.

Unknown

depends on heat loads and water temperature requirements.
if you're only looking at 3 grand difference between a high efficiency boiler and a water heater, that's not bad. but if it's a regular efficiency boiler the water heater won't run that much less efficiently.. if at all, depending on how it is controlled. A good tank water heater can hit 80% doing low temp heating if it can meet the load.

If this is a full size house in a heating climate with regular insulation, and you are going to use this system a lot, I would probably go high efficiency, but it depends on what the specific boiler is you are considering and what it is really being asked to do.

I

joet

keeping backup

"You say you use the steam system as a back-up on cold days. So do you need to have a heat source to supplement the pellet stove and radiant floor on some days? "

Yes I do need to support the pellet stove. The stove keeps the house at a consistent temperature down to about 15 degrees. When evenings go below zero, inside temps drop to low 60s and it takes forever to bring back up to 66.

I think I have three choices. One is to keep the oil fired steam as backup. Second choice is to add two radiant loops on the main floor in the main house to stabilize temps when cold. I imagine this can be done with a low water temp product. And another choice is to add a Buderus boiler that can heat the radiant (with or without the 2 new loops) as a well as be a boiler that will utilize the steam radiators that I have in the first and second floor.

"Also, do you have any idea how much of a load demand your radiant kitchen will put on the heat source? "

What I discovered this fall regarding heat load, is that if I set my tankless dhw heater on the 25 year old Weil-McClean boiler at 160 degrees, the temps that come out of the heat exchanger for radiant barely reach 100 degrees. I ran this way last winter and was dissapointed with the stability of kitchen temps. So I set the dhw temp at 200 degrees and get 110+ degrees into the kitchen floor. Problem is the boiler burned through 250 gallons of oil in 50 days. During summer months we burn around 75 gallons for hot water over the same time period.

As I write this now, I wonder if there is schmutz built up in HX? There does not appear to be a drain for this. hmmm

Erich_3

Navien Hot Water Heater

Since you have gas available I would install a Navien A model on demand gas fired water heater. That way you will not need to have a boiler running in the non-heat times. I would leave the steam boiler in place. Here is a link to Navien:

http://www.navienusa.com/

Charlie from wmass

Joe it sounds like you are using the tankless on the boiler for domestic water and radiant heat? They need to be seperate for safety on the domestic side. Also a domestic coil may not have the capacity to heat the radiant zone.

joet

whats the difference between a Navien and a Takagi?

Home Depot Employee

Besides efficiency, sch 40 pvc venting up to 100', alot

Mark Custis

What

about the steam system?

Jamie_5

system heat emitters?

As NRT.Rob says below, it depends on your system. If you are planning to leave the steam radiators and piping in place, I would worry about (1) the pipes springing leaks if converted to hot water and (2) the radiator sections being joined appropriately for hot water. In that case, I would probably leave the steam boiler in place and run the one radiant floor off a heat exchanger on the gas water heater. But if you're repiping, adding more radiant zones, etc., a mod-con boiler with indirect would seem the way to go.

joet

Steam radiators will stay in place and I'm not thinking about a hot water system. oil fired steam will stay in place.

If I go hot water heater for domestic and run a HX for radiant, what water temp will i need to run in the heater to get 120 into the floor.

Jamie_5

heat source temp

It depends on the load of your radiant floor and the characteristics of the heat exchanger, as well as the flow on the two sides of the exchanger. But I'm willing to bet that 140F temperatures at the water heater would suffice. Plainly, you would need to temper the domestic water coming out of the water heater if it is run that hot.

Take a look at the Taco X-Block, which is an all-in-one heat exchanger, pair of pumps, control package. The instruction sheet for that unit includes sizing guidelines.

Mad Dog_2

Don't send a \"boy\" (HWH) to do a \"mans\"(boiler) job

I have done quite a bit of experimentaion over the years on this subject....and, it most cases.....a boiler is a better investment in EVERY way. Mad Dog

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

hot_rod

define \"water heater\"

some of the high efficiency mod con water heaters make excellent radiant heat sources.

HTP, Polaris, Bradford White, AO Smith and others build a tank style condensing WH.

The HTP Voyager is a tank condenser with an optional radiant coil inside.

The solar Phoenix goes a step further with a solar coil for input from a solar panel, modulating burner, and with an external hx or Taco Radiant HX block makes a nice radiant and DHW high efficiency power plant.

hr

clemmer

no more days off

what is the gas rate in your area. normally by the time you add up gas cost than the transportation surcharges then the monthly meter fee than times it by 1.4 because you are getting a 140,000 btu in a gallon of oil an only a 100,000  btu in a therm of gas you are not really saving all you are doing is supporting coporate america/big buisness. Everybody thinks they are going to save so much when switching to gas. Than add in what they are doing to the ground to get the gas out.