Best oil boiler for Radiant heat + hot water

Pete - CT

Thanks,

That's probably what I'll do. I have a stonelined indirect tank now with a built in heat exchanger for my hot water... Maybe I'll just add an aditional one for the Radiant.

I have the power vent that I installed when my chimney failed - Any sugestions on a base setting for the "damper" I have a feeling the tech that tuned the furnace didn't really understand the system & may not have taken that into considiration. I don't want too much draft.

It is running well now. We had alot of issues when we installed it 10+ years ago, but most weren't really EK's fault (poor draft do to oversized chimney - the system would shut down, 2 bad control boards, multiple zone valves, etc.)
I guess I would be best to run it until something expensive fails.

On another note - I haven't been thrilled with the honeywell zone valves (several have faild, plus it seems like water slips by when they are closed?). Should I switch to Taco?

Pete - CT

Best oil fired boiler for radiant + hot water

Hi,

I am installing a fully radiant system for my 2,000sf home. I need to replace my energy kinetics system 2000 at the same time. (I think)

What would be the best boiler that supports direct vent? Is it realistic that I can set it up my self, then have a pro "tune" it?

I was thinking about the Toyotomi OM-180 On Demand Water Heater.

Any thoughs or suggestions?

Thanks,

Pete

chapchap70_2

What's wrong with the EK? If you replace it with another brand, you will probably burn more oil (or gas?) You can do radiant off the boiler with a buffer tank.

Constantin

The \"best\"?

I suppose a condensing boiler might be the right answer to your type of application... for example, the Monitor FCX might be the right size for your application, and it'll love the low water return temperatures your radiant system can generate. Finding someone qualified to install and maintain one is a different matter, however. Peerless has also brought out a condensing oil boiler...

On the non-condensing side, the smallest Vitola or Burnham MPO weigh in at around 72-74kBTU/hr output. The EK series of boilers doesn't drop below 100kBTU/hr, so they're likely to be 2x oversized or more for your application, leading to short cycling unless they have a buffer tank to use. Speaking of which, what is your heat loss?

Joe Brix

The OM-180

is a greeat concept: a small 80 lb oil boiler with a stainless heat exchanger. But the 148K output, unknown oil burner and Devalan XA nozzle are negatives. You must have to get a big buffer/indirect tank to keep it from short cycling.

Pete - CT

Monitor

Is the Monitor FCX worth the $5500 cost? That's double everything else....

I haven't done a formal heat loss, but it's R26 w/new windows.

The current EK boiler is 150kBTU (was powering big cast iron radiators) I guess it could soldier on with a buffer tank... I was hoping to get someting that didn't require forced direct venting amoungst other things....

chapchap70_2

If there is no mechanical problems with the boiler, you may be able to get a large (well insulated) indirect/storage tank that will serve both your hot water and radiant needs. You need to separate your radiant water from your domestic hot water but that can be done.

As you probably know, your boiler ends cold by dumping the leftover heat into the last zone that called
(which I guess in your case would be exclusively the storage tank) so the fact that it is oversized is basically meaningless.

When a boiler is taken apart (for service) it has a higher and higher probability that it will no longer be flue gas tight as it gets older. If you do not have a chimney, I would power vent for this reason so the motor drives the flue gases out of your home.

Unless your boiler is on the fritz, it will take a lot of time to recover the costs of replacing the boiler since there are not too many out there that will use less energy. If you do not spend about what you were talking about for the Monitor or another brand, you will use more energy.

chapchap70_2

Hi Peter,

Believe it or not, if the power venter on the System 2000 is not set up properly, it will most likely be running with too LITTLE draft. Energy Kinetics wants between a -.10 and -.12 draft; the reason being to compensate for windy days. It must be set up with a draft gauge. Also, EK states that a power venter on their boiler MUST have fresh air intake piped from outside the home to the burner. You should see a 3 or 4 inch PVC pipe run from outside the house to the burner cover box. This also cuts down a bit on fuel usage due to the fact that you are not using heated air to run the burner. I believe many power venter companies want their power venters piped with fresh air from the outside no matter what boiler you may have.

As for the zone valves and other controls repeatedly breaking, I suspect something else is wrong that is causing this. Do you have a system by-pass? EK states that their boiler MUST have one. I think that would be a 3/4" pipe on your unit that starts between the supply outlet on the boiler and the zone valves and ends in the return piping before it re-enters the boiler with a ball valve in the middle. If you have a "Classic" manager, your boiler can run without the by-pass but it will not run right and it can wreak havoc on the controls.

I suggest you find someone that is familiar with the System 2000 boiler and have him add the buffer tank plus set it up according to how EK wants it. If the person arrives at your house and cannot produce a System 2000 tech manual, show him the door and have someone else do it.

H.R

SYS.2000

Hi Peter,

Taco Zone valves would defeat the primary purpose of having a SYS 2000. Honeywell 4-Wire zonevalve motors had a LOT of problems. I have actually switched to Erie 4-wire zone valves,alot less problems. Is the manager digital or "Classic"? The digital manager, alot of times, is changed because the temp light is flashing 140 degrees. Because the both switches are turned off when they change the PCB,it resets the manager and the problem disappears (temporarily). As far as the power venter, chapchap70 is correct -.10"WC is min. you also need air inlet directly to the burner, on the same wall as the power venter.Preferably 10ft away.

Pete - CT

O.K. guys, thanks. I'll have to make sure the next time the guy comes to clean/adjust it, I'm home.

I installed the power vent (And yes, the PVC outside air intake) my selft. Then I called the installer in to tune it & mentioned that the draft would need to adjusted. When I got home it was on the same setting I had left it on. I was either close enough when I set it up, or he never checked it.

Also, I do have the bypass piping. (and the classic board - It was installed in 1995) Originally there was a heat exchanger there for my hot water (going to a converted gas heater used as a storage tank). I installed a new indirect hot water storage tank with it's own built in heat exchanger. (vaughn top performer plus). I understood it was needed to keep the boiler temps up to prevent condensation, so I piped it through.

I would think I could pipe it just like my hot water storage tank? (Other than I added a seperate circulator for the hot water zone - This was to assure hot water Priority when the big old cast iron radiators where also calling for heat. I have a 35 gallon for the water, any estimate on what size to use for the whole house radiant?

Also, just for future reference - how to you feel about the current system 2000?

chapchap70_2

Without looking at your boiler, I am guessing that you piped in a tee between the supply at the boiler and the by-pass and put in a circulator before the indirect? If you piped it this way or similar, I do not see how you are getting the main benefit of the System 2000 design because the boiler would be maintaining temperature after a call for hot water is met. The way the system was designed is to have the btus dumped into the last heating or hot water zone that called so they wouldn't go up the chimney between calls. The boiler is supposed to sit cold when it is not running.

If there is a scale problem due to condensation, the aquastat temperature should be raised so the return water is above condensation temperature as it returns to the boiler for the few seconds the flue gases remain in the passages after the burner shuts off.

The proper way to pipe in an indirect would be the same as if you were piping another heating zone. That is to use the main circulator like the rest of your zones and pipe in a (EDIT: 2 wire zone valve WITHOUT end switch. Brain freeze?) the same way as the rest of them.

I cannot tell you what size buffer tank you need without knowing the heating load the radiant requires. If you insist on putting the buffer tank in yourself (and fixing the way the hot water is set up) contact Energy Kinetics for their manual. (or show yourself the door!)

The main difference in the new System 2000 is that you can clean it from the front which allows it to be put into tighter spaces. The one you have is still available as far as I know, but comes with the digital manager. As far as heating the house and efficiency, there is little difference.

Pete - CT

No, its piped off of the hot water zone properly. I just added a circ to the hot water zone because EK thought the large cast iron radiators might get all the heat when it was cold outside - preventing enough flow to the hot water exchanger....

I'll check with my radiant designer to get an idea on the tank size.

chapchap70_2

Are you sure EK told you to put a circulator in the hot water zone? Hot water priority can be accomplished with a simple jumper wire according to their manual.

With two circulators working for the hot water zone, the water is probably flowing too fast for the coil in the indirect to properly extract the heat when the hot water zone is the only one calling. Some would think the 0010 (or bigger) you probably have as the system circulator itself may move the water too fast for the indirect to most efficiently extract the heat.

Pete - CT

Yeah, They actually faxed a diagram & everything.. The heat exchanger in the tank is pretty large (3/4 finned copper in a spiral) so I think plenty of heat is extracted.

I think I will take it off now though - just one more item sucking power. Plus I'll have a spare!

chapchap70_2

Sorry, I mis-spoke about the indirect coil. Actually the domestic water is extracting the heat from the hotter boiler water inside the coil.

Energy Kinetics knows how its system runs better than me so I must be missing something. I guess it is a moot point now since you will no longer be using the cast iron radiators.

If you will have just two zones for water tanks, you may want to ask them if you can use a smaller main circulator. Maybe you can use the one that you currently have in the hot water zone when you are repiping it anyway.

As far as the zone valve failures are concerned, are the problems still occuring? I do not understand what H+R was getting at since the zone valves on your boiler should be two wire zone valves ...unless he was thinking of two wire zone valves and typing four wire and Taco does not make two wire zone valves. (The last half of the last sentence added)

Pete - CT

Yeah, I'm not going to worry about it now. It worked fine (may have been overkill) & I know I won't need it anymore. I should see if I can fine the faxed Instructions - I could email them to you just to satisfy curiosities...

Mine are indead 2-wire. They are working O.K. now - must have been a bad batch I guess.

Thanks for al of your help.

Pete