New Homeowner Questions about Peerless Boiler Setup

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Old 12-25-12, 08:38 AM
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New Homeowner Questions about Peerless Boiler Setup

Hi all, and Merry Christmas!

I've been doing a tremendous amount of research over the past few weeks about the boiler setup that we've got with our recently purchased home in an attempt to ensure that we've made our home as efficient and comfortable as possible. To that end, I was hoping the collective brain around here could help me to understand some pieces that are still eluding me...

Our home in Connecticut is heated with a Peerless Pro-04 boiler, installed in March of 2008. It's got a L7248C Honeywell Aquastat and a six-zone Taco zone controller. There are four heating zones in the house and the "sixth" zone on the Taco is a priority zone for the DHW, an indirect MegaStor 40-gallon tank. We've done an energy audit and confirmed the unit is running well and it's been recently cleaned and serviced.

Oil is running me about $3.70/gallon and electricity is around $0.18/kW.

So, here are my questions...any help is sincerely appreciated!

1. I presume the Peerless is a "cold-start" boiler? There's no low-limit setting available on the Aquastat and being relatively new I presumed that it was, but I couldn't find this explicitly stated anywhere.

2. I was looking to add an Outdoor Reset module (https://customer.honeywell.com/en-US...d=W8735S1000/U) to the system. What are your thoughts on doing this? Is it worthwhile?

3. It states that if we use DHW, we need a separate module to go with the Outdoor Reset (this one, I think: Honeywell AquaReset Domestic Hot Water Kit). Since the DHW isn't controlled by the Honeywell Aquastat, but rather through the Taco zone controller, is this necessary? Is it set up incorrectly to have the Taco controlling the DHW in the first place?

4. If we had the money to burn, would we be better off with a heat pump water heater (either an add-on like the Geyser-R, or a full replacement like the AirGenerate) than the oil-fired version? If we fully replaced it, could we shut down the boiler in the summer entirely, or is that going to cause issues?

5. The manual for the Aquastat talks about thermal purge and anti-short cycle settings, but they aren't available when I go through the settings. I know some of the older models of Aquastat had fewer features available. Are these features just not available in my model Aquastat because of its age, or is there something I need to do to activate them? Are they relevant to my setup? Would it be worth upgrading the Aquastat to get them?

6. The Hi temp limit on the Aquastat is set to 180. Is this the best setting for winter operation, at least until installing an outdoor reset? Should I adjust it down in the spring, and how does this affect hot water availability?

I know that's a lot of questions, but I thought I'd throw everything on the table. Any information you can collectively provide would be sincerely appreciated, and if there's something about my setup that I didn't provide, let me know and I'll dig up whatever info I can.
 
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Old 12-25-12, 10:28 AM
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1. I presume the Peerless is a "cold-start" boiler? There's no low-limit setting available on the Aquastat and being relatively new I presumed that it was, but I couldn't find this explicitly stated anywhere.
I don't think you need to presume. One can tell by observing it's activity. I don't think the 7248 has the ability to be configured as warm-start.

2. I was looking to add an Outdoor Reset module to the system. What are your thoughts on doing this? Is it worthwhile?
I have my doubts that your aquastat will respond to the ODR module installed. Your thoughts on the 'firmware' of the older aquastat are probably correct in that it may not have all the newer features available.

3. It states that if we use DHW, we need a separate module to go with the Outdoor Reset (this one, I think: Honeywell AquaReset Domestic Hot Water Kit). Since the DHW isn't controlled by the Honeywell Aquastat, but rather through the Taco zone controller, is this necessary? Is it set up incorrectly to have the Taco controlling the DHW in the first place?
DHW certainly IS controlled by the aquastat. The HIGH LIMIT of the aquastat remains in effect during a DHW call. Yes, you would need the DHW module in order to tell the ODR module that the current heat call is coming from the DHW and that it should over-ride it's setpoint setting and allow the boiler to fire to it's HIGH LIMIT setting without regard to the ODR setpoint.

Your setup with the Taco is fine at present.

I think that you might be better off looking at the Taco ODR module that plugs into the ZC panel, IF your ZC panel is a model that will support the plug-in. (what model is it?)

4. If we had the money to burn, would we be better off with a heat pump water heater (either an add-on like the Geyser-R, or a full replacement like the AirGenerate) than the oil-fired version? If we fully replaced it, could we shut down the boiler in the summer entirely, or is that going to cause issues?
I'm not at all familiar with either of those water heaters (will look at them later), but yes, if you went with another type of water heater you could shut the boiler down in the summer. I don't know that the economics of trashing a perfectly good indirect water heater would make sense though. Probably not...

5. The manual for the Aquastat talks about thermal purge and anti-short cycle settings, but they aren't available when I go through the settings. I know some of the older models of Aquastat had fewer features available. Are these features just not available in my model Aquastat because of its age, or is there something I need to do to activate them? Are they relevant to my setup? Would it be worth upgrading the Aquastat to get them?
Probably correct that the firmware doesn't support those features.

Relevant? Thermal purge... might save a few dollars in fuel in the LONG term. In terms of replacing the aquatat to gain the feature... might pay for itself in ten years or so (a WAG). Anti-short cycle... only if you have a short cycling problem now would it mean anything to you.

6. The Hi temp limit on the Aquastat is set to 180. Is this the best setting for winter operation, at least until installing an outdoor reset? Should I adjust it down in the spring, and how does this affect hot water availability?
Leave it on 180. That's a HIGH LIMIT. The boiler is only going to heat to the temperature it requires in order to satisfy the thermostat. During the warmer part of the winter, it may not even reach 180. You want it to be able to reach high limit if it HAS to.

If you do add ODR you MUST leave the high limit at 180 because the ODR will make the changes.
 
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Old 12-25-12, 05:23 PM
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I have my doubts that your aquastat will respond to the ODR module installed. Your thoughts on the 'firmware' of the older aquastat are probably correct in that it may not have all the newer features available.
I found out about the ODR in the instruction manual for the 7248 that I downloaded; I'd never heard of the thing before that. So I presume *some* of the 7248s can interface with the ODR module, but maybe/maybe not the one I have.

Both Honeywell and Taco estimate savings of around 10-15% using such a setup, so either way it seems like it'd be a worthwhile investment, even if I saw half that (we're looking to spend around $3,000 this year on oil alone at the rate we're going, and we haven't been using two zones at all and have a pretty aggressive setback programmed into the thermostats).

I think that you might be better off looking at the Taco ODR module that plugs into the ZC panel, IF your ZC panel is a model that will support the plug-in. (what model is it?)

The ZC is a ZVC406 (not, as far as I can tell, an "EXP" version), so from what I gather the Taco ODR wouldn't be compatible, either.

But, just to make sure I understand this right: the Taco module basically cuts off the signal to the Aquastat that there's a demand on the system if the outdoor temperature is above a certain value, right? It doesn't reset the Aquastat's high limit directly, it just never "tells" it that there's a demand, so the Aquastat doesn't fire (unless there's a DHW demand on the system...).

Just looking at the cost of components, since the ZVC406 isn't compatible with an ODR module, it seems like I'd still be better off with the Honeywell ODR and DHW modules, even if that means rewiring the DHW zone valve to the Honeywell unit, just on the basis of cost, particularly if the ODR will work with the 7248 I have. Thoughts?

I don't know that the economics of trashing a perfectly good indirect water heater would make sense though. Probably not...

Because we haven't been in the house that long, I don't have good data on the cost of running the DHW system as it's currently set-up. I've heard of people blowing 200 gallons of oil during the off-season just for DHW, and if that's the case I think we'd pay back the investment of switching in a year or two. But it's possible that this estimate is based on a less efficient system than we have. Anybody have any good estimates on how much oil you burn for hot water only in the summer?

Leave it on 180...You want it to be able to reach high limit if it HAS to.

I'm just curious, trying to understand how this all fits together--but why 180? Just for the sake of argument, let's say that I didn't install an ODR and reset the high limit to 170? Would that save money, presuming that high limit was sufficient to keep my house warm?

If I'm understanding correctly...you ideally want the high limit to be set so that it is no higher than it needs to be to sufficiently heat your home, which is indirectly related to the outside temperature (how hard it has to work to heat the home). That's ultimately what the ODR does, right?

I'd read somewhere that the baseboard heaters work more efficiently at higher temperatures, but is that just a function of how fast the place heats, at the cost of higher oil consumption?

Thanks for all the feedback so far--this is exactly what I was hoping for!


 
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Old 12-25-12, 06:31 PM
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I presume *some* of the 7248s can interface with the ODR module, but maybe/maybe not the one I have.
Correct. The newer models will. Yours from 2008, probably not, but I don't know of any way to test to find out. It's not like you can hook up to query the firmware version. I haven't seen any literature from Honeywell that points out the fact that the newer stuff might not work with the older stuff. There should be a way to 're-flash' the micro with new firmware, but I guess Honey is counting on selling more aquastats if it can't be done.

estimate savings of around 10-15% using such a setup,
That's a pretty optimistic number IMHO.

have a pretty aggressive setback programmed
While every energy saving advice I've ever seen says that heavy setbacks will save oodles of fuel, I beg to differ.

There's no arguing the fact that by reducing the 'driving force' of heat migration and loss by reducing the differential between outdoor and indoor temps, there simply HAS to be a 'tipping point'... a point of diminishing returns, or possibly even HIGHER fuel use.

There is also no arguing the fact that RECOVERY from a setback period uses MORE fuel than MAINTAINING the temperature.

I did some experiments several years ago with setback, etc... keep in mind that I have an elapsed time meter on my boiler and that I know exactly (well, as exactly as the tolerance of my oil nozzle and fuel pressure gauge allow) how much oil I burn... and I track degree days... and plug numbers into a spreadsheet every few weeks... and derive a 'constant' of "Degree days / gallon" (oil delivery companies use this constant they call the " K factor " to determine when to make automatic deliveries of fuel...

So anyway... I still do this, but back in the day, I did more experimenting... and I maintained an agressive setback for a month, and then set the t'stat on 'hold' for a month. Honestly, I didn't see any difference.

This chart from JAN-MAR of 2007 illustrates:



Throughout Jan I used a 6 setback at night and on workdays. In Feb I pushed the hold button. I expected to see a 'bump', but there was none...

Note that there is a red line, B/D/S, which is BTU / Degree day / square foot, which was being used to compare charts with others who were using gas rather than oil... don't let that confuse ya... the green line is the 'k factor'

One interesting point to note on this chart is that as soon as Old Sol 'turned the corner' on March 21st, even though it got cold again that year, oil usage dropped... proof of the power of the Sun! (as if we needed proof!)

But I digress... badly... bottom line is that setback ain't all it's cracked up to be.

more...
 
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Old 12-25-12, 06:40 PM
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estimate savings of around 10-15% using such a [ODR] setup,
That's a pretty optimistic number IMHO.
SOME homes... yes, I believe one could see 10-15% savings. Homes with high heat loss and a way oversized boiler... maybe...

If a home is well constructed with adequate insulation and air sealing, I doubt if one would see anywhere near those numbers. Maybe 5%, but with the price of oil, that's not bad! It IS worthwhile.

Remember that with a typical CONVENTIONAL (NOT modulating/condensing) boiler, that one can only perform a PARTIAL ODR. The 'bottom end' of the ODR curve needs to be 'capped' around 140-150 because operating a boiler below this temperature is asking for problems with flue gas condensation which will ROT OUT the boiler, flue pipe and chimney. Flue gas condensate is ACIDIC!

more...
 
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Old 12-25-12, 07:03 PM
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what I gather the Taco ODR wouldn't be compatible, either.
Bummer... so I guess there's no connector near the upper left of the panel then?

the Taco module basically cuts off the signal to the Aquastat that there's a demand on the system if the outdoor temperature is above a certain value, right?
Yes, more or less... it's a 'sliding scale' though. Not just a single cutoff point.

It doesn't reset the Aquastat's high limit directly, it just never "tells" it that there's a demand, so the Aquastat doesn't fire (unless there's a DHW demand on the system...).
Right, again, more or less...

The Honeywell ODR communicates digitally with the aquastat and actually tells it what the ODR setpoint is. The HIGH LIMIT is still in effect for safety reasons, but the a'stat is told by the ODR what the cutoff setpoint should be.

If using the Taco with a ZVC or SR panel, then your statement is exactly correct. The Taco panel would simply drop the heat demand signal.

Not sure about the Honeywell, but if using the Taco, the system pump would have to be wired to the Taco panel rather than the a'stat terminals. If this weren't done, the pump would stop also...

I think the 7248 is smart enough to deal with this...
 
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Old 12-25-12, 07:04 PM
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There is an additonal limitation to savings from an outdoor reset (non-condensing). Generally, you want to run the boiler temp at the lowest that will avoid flue condensation, perhaps 150 deg or higher, and still heat the house. ODR will jack up the boiler temp when the outside temperature is higher, reducing boiler efficiency. If the radiation is oversized, which is very common, you can still heat the house with the same boiler temp as at normal outside temps more efficiently. ODR makes the most sense when the installed radiation rating is less than needed to heat the house on a cold day (common, but not rare).
 
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Old 12-25-12, 07:32 PM
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since the ZVC406 isn't compatible with an ODR module, it seems like I'd still be better off with the Honeywell ODR and DHW modules, even if that means rewiring the DHW zone valve to the Honeywell unit, just on the basis of cost, particularly if the ODR will work with the 7248 I have. Thoughts?
Yes... sounds right. PexSupply is getting about $220 for the 406-EXP and about $280 for the PC700, so right there yer at 5 bills...

The L7224 WITH THE ODR MODULE INCLUDED is only $233 ! You would still need the DHW module

L7224R1000 - Honeywell L7224R1000 - 120 Vac Oil Electronic Aquastat Controller w/ Outdoor Reset Module

Ya know what? I just looked at the 7224 install sheet again... I'm not so sure you need that DHW module after all.

ZR-Domestic Hot Water (DHW) Request

The ZR terminal can be selected to service an indirect
water heater heat request. This parameter is set via the 3
digit display (see Adjusting Settings section of this
document). A heat request via the ZR terminal will have
priority over all other features such as the Anti Short-
Cycle feature or those enabled by the Outdoor Reset
Module (See form #69-2335 for more information).
No............... you would still need another relay of some sort because the ZR input is 120VAC.

But looking at the DHW module from Honeywell, I don't understand what that's for... there's no hot water demand input to it, it's just a sensor for the hot water lines...

It's late, I'm getting stupider and the eggnog is getting stronger...
 
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Old 12-25-12, 07:33 PM
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I think your DHW is on a zone valve you said? No separate pump for DHW?
 
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Old 12-25-12, 07:54 PM
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I've heard of people blowing 200 gallons of oil during the off-season just for DHW
That's crazy! Perhaps those folks were running a 'tankless coil' and NOT an indirect?

I can't imagine more than 10 gallons a month to make hot water.

Anybody have any good estimates on how much oil you burn for hot water only in the summer?
Hopefully some readers with indirects will chime in... I have an electric so I can't help there...

but why 180? Just for the sake of argument, let's say that I didn't install an ODR and reset the high limit to 170? Would that save money, presuming that high limit was sufficient to keep my house warm?
For many years... decades... forever... 180 has been the de facto 'standard' that systems were designed around. Radiation was installed based on this temperature water. If designed 'by the book', a home would require 180 water to meet the heating needs on the coldest days of the year. All other times one can get by with less temp (case in point, ODR).

Yes... if you don't have a problem remembering to adjust the a'stat yourself, you could be your own biological ODR... warmer weather you certainly could turn the high limit down. Just remember the flue gas condensation issue and don't go lower than say 150 or so. And when it gets real cold out and the heating system can't seem to keep up, remember that you turned it down!

That's ultimately what the ODR does, right?
Yes, it remember to kick it up a notch so that you don't have to...

BUT... remember that you have an indirect water heater! The lower you set the high limit, the longer recovery time for the water heater.

read somewhere that the baseboard heaters work more efficiently at higher temperatures, but is that just a function of how fast the place heats, at the cost of higher oil consumption?
Not more efficiently... but higher BTU output. The hotter the entering water, the more BTU output they produce. This is exactly the attribute that the ODR exploits. In warmer weather (aka "the Shoulder Seasons") you don't need the max output to maintain temp.

There's another point about ODR to be mentioned... it increases the comfort level in the home. Because when there is cooler water running, the circulator will run longer to circulate that cooler water... the temperature in the home remains more constant.

You may notice that if you are sitting around and start to feel a bit of a chill... next thing you know, you hear the t'sat click... then, a few minutes later, it's just a tad to warm... because the 180 water is giving a BLAST of heat... flooring it off the line and laying rubber... then jamming on the brakes and sitting at the stop light.

With ODR it's a gradual acceleration, and by the time you approach the light it has turned green again and you hardly need to tap the brakes.
 
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Old 12-25-12, 08:33 PM
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Strike, on your 406 panel, is there a set of unused terminals labled something like

"Zone 6 relay" ? NC COM NO ? anything like that?

If so, these contacts should be suitable for use wiring to the ZR terminal on a 7224 that has been configured for ZR = duu .

Then, you would not need the DHW module at all...

Doug, curious...

When you wrote:

ODR will jack up the boiler temp when the outside temperature is higher,
Did you mean:

ODR will jack up the boiler temp when the outside temperature is LOWER,... ?

I don't understand your logic in this statement:

ODR makes the most sense when the installed radiation rating is less than needed to heat the house on a cold day
If you don't have enough installed radiation, then it wouldn't make much sense to run lower water temp, would it? Am I misunderstanding something?

OK... I've thought about what you wrote a little more and sorta understand.

If you have MORE radiation than needed, there's a good chance that there's no point in the ODR anyway, because you may never even need to approach the high limit setpoint to heat the home, even on the coldest days (like my home)...

Still, I might amend this:

"...most sense when the installed radiation rating is less than needed..."

to say:

"...most sense when the installed radiation rating is EQUAL TO THAT needed..."

Because if you don't have enough radiation, you will need a temp HIGHER than 180 to meet the heat loss.

Is that what you meant?
 
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Old 12-26-12, 05:09 AM
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Remember that with a typical CONVENTIONAL (NOT modulating/condensing) boiler, that one can only perform a PARTIAL ODR. The 'bottom end' of the ODR curve needs to be 'capped' around 140-150 because operating a boiler below this temperature is asking for problems with flue gas condensation which will ROT OUT the boiler, flue pipe and chimney. Flue gas condensate is ACIDIC!
All right...I can see now that my understanding is incomplete on how some of these pieces fit together, at least in what the exact meaning of the various terms that I'm seeing.

What is the difference between a "cold-start" boiler and a "condensing" boiler? It makes sense to me that without a method of processing the condensate during latent heat transfer, you would corrode the boiler/flue pipe/etc., which is why there's a "low limit" on a conventional boiler. But my Aquastat doesn't seem to have a "low limit", or at least one that can be read and/or set using the controls provided. Peerless doesn't label my boiler as being a "condensing" boiler, so I presume that it is not. I was under the impression that the terms were related, but now I'm thinking I've got that wrong...
 

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Old 12-26-12, 05:17 AM
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But looking at the DHW module from Honeywell, I don't understand what that's for... there's no hot water demand input to it, it's just a sensor for the hot water lines...
I'd thought a lot about this, and all I can come up with is that it wants to measure the output temperature of the DHW to make sure that the high limit it has set is sufficiently meeting demand...i.e. if the DHW temp flowing in the pipe starts to lag, it might reset the high limit to a higher value to do a better job of keeping up.

Just like the baseboards don't need to work as hard during the shoulder seasons, so it reduces the high limit...if there's only a moderate demand on the DHW, why reset the high limit to 180? That's all I can think of, anyhow, that would explain the temp sensor for the DHW.
 

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Old 12-26-12, 06:07 AM
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I can't imagine more than 10 gallons a month to make hot water.
Because I don't have any real data to use for this for my particular setup, I don't think we'd pull the trigger on changing the DHW system until we went through at least one or two summers to see what our actual usage is. I asked the previous homeowner and oil company for their fill numbers to get a better estimate, but neither responded, so I'll just have to wait to get the data myself.

Bummer... so I guess there's no connector near the upper left of the [Taco] panel then?
Nope. Just the connection for the transformer, but not for the expansion connections.

I think your DHW is on a zone valve you said? No separate pump for DHW?
That's correct. There's a common manifold for the four heating zones and the DHW "zone" (Zone "6")--all on a single pump.

Strike, on your 406 panel, is there a set of unused terminals labeled
something like "Zone 6 relay" ? NC COM NO ? anything like that?
Yeah, they're there, and unused. If I wire that up to the Zr terminal on the Aquastat, what exactly is that doing that isn't being done now?

While every energy saving advice I've ever seen says that heavy setbacks will save oodles of fuel, I beg to differ.

I think I'll need some time to fully digest the information that you've provided, though I admit I was skeptical of the gains of setback because of the energy used in recovery. Though I've been tracking degree days to compare against my oil usage, because I'm using such rough numbers (such as how many gallons I buy over a month or two period rather than for a given day), I don't have the kind of data points to compare, so I've sort of gone on faith. I'm just curious--how do you measure the oil burn--do you measure how long the Aquastat is calling for the boiler to operate (electrically) and calculate consumption based on the nozzle size, or do you somehow measure oil flow rate directly?

Obviously, the gist of all of this is trying to find every way I can to make our home run more efficiently, and since we expect to be here in the long run I don't mind spending a few hundred--or even a few thousand--bucks if the payback will take a few years. I don't think oil's getting any cheaper! But there's so much marketing BS out there, on top of good old wives' tales even among professionals that it's hard to know what to believe.
 
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Old 12-27-12, 12:40 PM
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Sorry for delayed response, hard drive crashed... just got the new one up and running... now I've got to reload all my programs... I hate computers!

Strike, on your 406 panel, is there a set of unused terminals labeled
something like "Zone 6 relay" ? NC COM NO ? anything like that?
Yeah, they're there, and unused. If I wire that up to the Zr terminal on the Aquastat, what exactly is that doing that isn't being done now?
You don't need to do that yet, not until you install the ODR... when you do, what that will do is signal the a'stat to over-ride the ODR settings.

I'm using such rough numbers (such as how many gallons I buy over a month or two period rather than for a given day
Longer term averages are BETTER. My data collection is a week at a time.

how do you measure the oil burn?
I have an elapsed time meter wired to the oil valve circuit on my burner. It records the amount of time the oil valve is open, and since I know my nozzle is 0.6 GPH, a quick multiplication tells me how much oil has been burned. It is of course only accurate to the degree that the stated nozzle flow is, and the pressure gauge I use to adjust the pump pressure (nozzle flow is related to pressure). Yes, electrically.

I don't mind spending a few hundred--or even a few thousand--
Insulation, it's fuel you only pay for once.
 
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Old 12-27-12, 04:56 PM
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Sorry for delayed response, hard drive crashed... just got the new one up and running... now I've got to reload all my programs... I hate computers!
Don't get me started. And I'm a technology program manager!

I have an elapsed time meter wired to the oil valve circuit on my burner.
Makes sense. I might wire something like that into the system.

Insulation, it's fuel you only pay for once.
Already on it.

Originally Posted by Myself
What is the difference between a "cold-start" boiler and a "condensing" boiler?
Yeah, I'm quoting my own stupid question, but this is still confusing me. I hate admitting ignorance on this one, but I'd rather stick my neck out there and make sure I've got it straight...

Strike, on your 406 panel, is there a set of unused terminals labeled
something like "Zone 6 relay" ? NC COM NO ?
This is really the only question I have left--once I get the right equipment, how would I wire the NC/COM/NO terminals to the aquastat? I haven't seen a wiring diagram that really addresses that situation in the aquastat manual...
 
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Old 12-27-12, 05:59 PM
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but this is still confusing me. I hate admitting ignorance on this one
I don't think I answered this one? or did I?

A cold start boiler will, in the absence of any demands, go stone cold... it won't fire unless something tells it to. When it is told to fire it will, if necessary to meet the demand, fire all the way to high limit.

A warm start boiler will keep itself in a programmed (by the low limit and the diff) temperature range 24/7, UNLESS there is a heat call, in which case it will behave as above.

If either of the above are equipped with ODR the high limit setpoint will be controlled by the ODR.

A condensing boiler, which is almost without exception (probably IS without exception) always going to be a 'modulating / condensing' boiler.

These are boilers that are designed of materials that will withstand the corrosion caused by the acid condensate. They can run all the way down to room temperature if they need to.

They also MODULATE, which means that the heat output varies. A typical gas fired mod/con might be able to vary it's output from say 25K BTUH up to say 80K BTUH. So, not only is the water temperature under control of the ODR, so is the burner firing rate.

once I get the right equipment, how would I wire the NC/COM/NO terminals to the aquastat? I haven't seen a wiring diagram that really addresses that situation in the aquastat manual...
I think there is a diagram that comes close... look at figure 9, it shows the use of 120VAC from a line voltage aquastat on an indirect to signal the ZR.

We would need to work out all the specific details, but basically what you would do is configure the a'stat to use the ZR terminal as a DHW DEMAND input. This would tell it to fire to high limit and ignore the ODR setpoint. It might not go to high limit if the DHW tank is satisfied before then, but it COULD if it had to.

Basically, you would wire 120VAC HOT to the COM on Z6 relay, and the NO contact would wire to the ZR.

You might not have to make any other changes... but the question of how your pump is wired now still enters into it... did you tell me that already?

Is your pump currently wired to C1 and C2 in the a'stat? or to the 406 terminals?

I do NOT think that a pump wired to C1/C2 on the a'stat will run when there is a DHW call on the ZR, so the pump wiring would need to be moved to the 406 panel most likely.

In addition to the Zone 6 relay, there is also ANOTHER set of contacts to the left of that terminal strip, correct?

Give me the details of what's wired where and I'll figure it out.

I can't make any drawings now though becuz I've lost the install disks for my cad program. They're here somewhere... the empty box is on the bookshelf... but whereinhell did I put the disks? Under which pile of papers are they hiding?
 
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Old 12-27-12, 08:15 PM
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A cold start boiler will, in the absence of any demands, go stone cold... it won't fire unless something tells it to. When it is told to fire it will, if necessary to meet the demand, fire all the way to high limit.
So here's my only question: what happens if a cold-start boiler (that is not a condensing boiler) cools boiler water down to 90 degrees before a demand is placed on it (since there's no low limit). Is the fact that the boiler goes "full bore" the reason why it doesn't have condensate damage, as opposed to the modulating function of the condensing boiler?

[Edited repeatedly because I'm trying to figure all this out]
 

Last edited by strikefinder; 12-27-12 at 08:31 PM.
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Old 12-28-12, 12:41 AM
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Strikefinder,
Something to look into also is either Beckett heat manager or Intellidyne HW+. The Intellidyne is the heat manager with an LCD readout instead of led lights and gives options of setting setpoints differently as well as a DHW lead (option). It calculates how fast the temperature is dropping (on output pipe) based on system load. One temp sensor on output pipe and wires as it's own switch between B1 lead and B1 wire. When Aquastat says "turn on" HW+ says wait...let me see...150 degrees water temp barely dropping (its 60 outside for argument) let that circulate for a couple minutes to see if I really need to fire. 10 minutes later thermostat was satisfied and boiler never fired. Next round (Indirect water heater demand because your in shower) temp dropped quick as water was scrubbing heat fast it said yes fire now, don't wait. Taco/argo controller left all zones off except DHW so all heat focused on that until satisfied. Also had own "low limit" that if boiler was less than 120-130 (I think) AND there was a call for heat it let it fire right away. This made for less savings during summer because most of demand was 1-2 times/day and only from DHW.

At my old house the HW+ after about a week said I was saving about 30% and varied some but basically stayed about that for years. I had installed it early January and from that point on my oil usage went from 1000 gal/yr to about 700 and stayed so about right. Boiler setup was Weil Mclain WPGO-4 no coil, Amtrol Boilermate 40 gal Indirect water heater, 4 zones total (argo 4 zone controller) with 4 Taco 007's. House not great on insulation. I also added later a Field Oil Vent Damper which saved another 50ish gal/year from point of install.....and then I moved!

Oil usage was about 200-300 gallons for the early April - mid/late October time frame based on that indirect hot water setup. Wife and 2 kids that REALLY like long/hot showers and a hot tub (300 gal) that got filled a couple times with warm/hot water during pool season.

Beckett also now has a new aquastat (called aquasmart) that has heat manager built in as well as a LWCO sensor as well as multiple setting for hi/low limits and temperature differentials for both as well as off to be used as cold start. Shop by recommended it in place of a honeywell with no lower limit. less cost more features. I want to call Intellidyne and ask a couple questions on it. They were VERY helpful years ago when I bought the HW+. I had called to ask about it vs. the beckett heat manager and from commercial by me then the "wave home solutions" version.

I'm trying to decide on my new house whether to go back to the HW+ or the aquasmart (or both) but need to install indirect water heater as part of it.
 
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Old 12-28-12, 08:02 AM
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Is the fact that the boiler goes "full bore" the reason why it doesn't have condensate damage, as opposed to the modulating function of the condensing boiler?
Actually, there will always be 'some' damage. It's unavoidable to a degree.

As long as the burner cycle is long enough for the system to come up to temperature quickly enough that it DRIES OUT the acid laden moisture on the surfaces, there will be no 'significant' damage.

Sequoia, I'm glad you were happy with the HW... My opinion differs. I had one and it didn't save me a dime. There ARE systems that it will work with and save some fuel. Let's just say that on systems that have over-sized boilers that regularly 'bounce off' the boiler high limit when operating, they may be a fuel saving add-on. The newer models with the improved firmware address some of the issues I had with the earlier models. I haven't tested one so I don't have an opinion but am willing to give benefit of doubt.

But we don't want to hijack Strike's thread with yet another discussion of the HW thing...

I will agree that the AquaSmart is worth looking into.
 
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Old 12-29-12, 03:24 AM
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NJtrooper,
I was looking at all that both of you said in the thread before it went to all the condensing boiler ideas and just adding what I had plus the Indirect water heater summer experience which you had asked for somebody that had one and gallons used. How many systems out there like strikefinders new house (and mine) are actually size "correctly". The price of all the ODR modules he wants to try are the same or more than the HW+ or the Beckett Aquasmart. Without a large investment to redo everything to size it correctly so it never hits high limit and runs at prime conditions would be almost impossible. Unless I'm wrong from all I've read, the indirect water heater also needs a high heat input to operate at the recovery rates listed or you run out of hot water and get back to tankless coil status.

I'm not sure if Intellidyne (or Beckett) still list it but they used to guarantee 10% minimum savings. For $200 it might be worth a shot, though the aquasmart is only like $150 but I don't know if any guarantees on savings are offered. If it doesn't work for him I'm sure some other person willing to try it (like me) would buy it from him on ebay etc.

Mine was probably oversized like most but going from an old Repco with tankless coil to Weil Mclain WGO4 and boilermate brought me from 1400 gal/year to 1,000 gal/year. The HW+ brought me to 700 gal, and the OVD brought me to 650 gal/year. Not much else changed in house.

It didn't work on yours which is probably a much better setup but for me I was able to document a 300 gallons/year savings ($1055 at price I paid last week). For me that's worth a shot at a $200 money back if not happy with it investment. I had that for 3-4 years so it more than paid for itself. How much are the Heatpump water heaters to buy and operate vs. maybe 30 gal/month for the oil (pending how much water he uses). I know by me on Long Island LIPA is expensive. My friend added an electric water heater and his budget bill went up by a decent amount plus he runs out with 3 girls in the house.

Hour meter- I had a Fargo hour meter (elapsed time) that I installed on mine (I need to confirm on old paperwork but believe it was TH7AH Timer Specials). It had a front button reset on it. I used it as my old house had a 275gal tank sideways in the crawl space. 230gal was all that was usable (I ran out once). Knowing nozzle size I called when I could get 200 gallons for the price break. It was always within 5 gallons at fill up based on how fast they filled/shutoff. I connected it to the oil solenoid like NJtrooper and will on my new one also since I now have a 550gal in ground that needs to be "stick checked".
 
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Old 12-29-12, 09:25 AM
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Mornin'...

Like I said, I don't really want to discuss the "Heat Manager" thingys... it's all been said already, and I can't comment on the new ones because I haven't tested one. Maybe they are better.

I do like what I've read about the AquaSmart though so it is a viable possibility.

we don't want to hijack Strike's thread with yet another discussion of the HW thing...
 
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