New boiler: setting the aquastat and boiler temps.

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Old 01-20-18, 08:08 PM
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New boiler: setting the aquastat and boiler temps.

Hi, I've been dealing with a brand-new experience as the first-time owner of a new OIL boiler [three-days' worth of familiarity with the oil unit, after a lifetime of exposure exclusively to GAS boilers, since childhood], and I've been taken by surprise-- waylaid!-- by the mechanical version of the 19th century highwayman, who preyed upon unsuspecting travelers! I'm an unsuspecting oil boiler owner waylaid by my new boiler, as it suddenly is forcing me to deal with issues I hadn't anticipated and to answer questions that hadn't arisen with my old gas boiler.

So I'd like to pose these questions of mine to the forum, one at a time. Today I want to deal only with the aquastat's high temperature cut-off, and the first issue is that a careful perusal of my operation manual for the Dunkirk Empire II Series II, Model 3EW1.00 reveals no instructions for how to access and adjust the aquastat and yet the manual says the following: "Adjust Operating Controls: Use the following settings for first adjustment:

High Limit:
Baseboard and Convectors 200 degrees F
Standing Radiators 180 degrees F

(Incidentally, I have a gravity hot water system with standing radiators and no circulating pump.)

But clearly, in using the words, "first adjustment", the manual implies that the homeowner in my situation should begin with 180 degrees F as a first adjustment and might have reason to later adjust the high limit setting to a different level, and it certainly strongly indicates that the owner in fact has the ability to do so-- and yet not a word in the manual about how to do it! So how do you do it, and why is there not a word in the manual about how to do it?

Compounding the mystery is that I read online that some boilers have the high temp limit set by the manufacturer with no ability on the owner's part to change it. But how can that be the case here?: if I had a baseboard, the proper limit would be 200 degrees F and someone would have to adjust the limit up from its current setting, which appears to be about 180 degrees. It doesn't seem possible that Sears sent the installer a unit with its current setting of 180 degrees knowing it was for me and that I had standing radiators, which would mean it was set by the installer once he saw the set-up in my house, right?

And in examining the locations of the two aquastats (one from the previous boiler, one from this new boiler) it appears that both of them are actually measuring the water temperature in the heating system pipe ABOVE the boiler itself. Is that correct?

And I also noticed that when the thermostat setting was much higher than the current temp in the vicinity of the thermostat (so that it was the high temp cut-off in the aquastat that caused the boiler to go off, not the room temperature reaching the prescribed level) sometimes the new aquastat (the one that came with the oil boiler) would reach about 175 degrees, but other times 185 degrees. How can that be, since obviously its settng hasn't been changed and in both cases the boiler was going off due to the aquastat and not the thermostat?

And certain reputable websites (see say that instead of reflexively setting the high temp cut-off at 180 degrees, it is better to use 195 degrees or even 200! Is that a valid viewpoint?

I have more questions about the aquastat, but I don't want to exhaust any forum member kind enough to respond to my inquiries!
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Old 01-20-18, 10:25 PM
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Since every installation is slightly different we MUST have pictures of YOUR installation to be of much help. Beg, borrow or steal a camera (and a kid to operate it) and upload several dozen pictures.

In general, the high setting of the aquastat needs to be high enough to provide the needed heat in the house but the lower the setting the better will be your fuel economy. If YOUR system is able to adequately heat the house with a setting of about 160 degrees then that is the optimal temperature. Varying the boiler temperature according to outside temperatures can save significant amounts of fuel.

Near the end of the manual it gives a parts list. The aquastat is a Honeywell L8148A and doing a Google should give you access to the instruction sheet. My computer is being very temperamental now and I am having considerable trouble finding just about anything.
Old 01-20-18, 10:50 PM
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If we're going to help you.... please be succinct and to the point. No frill - no fluff- no backstory. I changed your title to exactly what your question is.

To members replying..... keep your replies and help on target. If you have nothing positive to add.... don't post.

You've been warned.

I am not a boiler technician but I can tell you that you must tread lightly. Since you don't have a circulator you don't want to push the boiler to close to boiling. You should have a new Honeywell digital aquastat. The link covers the settings and adjustments.

If I have the correct manual listed.... it shows the L7248L aquastat.
Please let me know if this is incorrect.

Boiler manual.... dunkirk/default/files/2895_0.pdf
Honeywell L7248L aquastat...... 1249544647674/17070_PROD_FILE.pdf
Old 01-21-18, 05:25 AM
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These new hot water boilers are not designed to be used on a gravity system. They are supposed to be used with pumped systems. You may experience short cycling and a shortened boiler life. One question; what sizes are the original old piping, supply and return, ?near the boiler and is it the same size as the boiler connection piping ?
Old 01-21-18, 06:17 AM
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Photos are going to result in much better answers here. Photos of the boiler, of the controls, of the loop, everything.
It is very important that the boiler be set exactly right. Water expands 1700 times it’s original volume when boiled. Boiler explosions are violent and extremely destructive.

I don’t know how well that particular boiler will perform in a gravity system.
Old 01-21-18, 09:39 AM
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LatestCraze –

I’m not an expert and don’t want to confuse the issue, but something jumps out at me. Maybe the other folks could answer this. But your manual says this on page 30 under “Equipment and Optional Accessories”:

CIRCULATOR (provided)

Every forced hot water system requires circulator. Separate circulator or zone valve is required for each zone, if there are two or more zones. ….

If you look at the figure 10 on page 13 it shows one possible pump position close to the top of the boiler.

So my question is” Are you sure you don’t have a pump? In other words, it may be much closer to the boiler than you think, and so maybe you are misidentifying it.

(yes I realize pictures would be definitive here)
Old 01-21-18, 09:54 AM
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He just bought the Boiler last week and insisted on its being "gravity feed".
Old 01-21-18, 10:43 AM
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Boiler explosions are violent and extremely destructive.
Can open systems like the OP's explode without an obstruction? I didn't think so, but I'm no expert. The last thing he needs is something more to worry about.
Old 01-21-18, 10:43 AM
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His original system is a gravity feed system which never had a pump to force the water around the system which was the way original hot water systems were before the addition of the pump.

His new boiler came with a pump as they all do and is standard equipment on hot water boilers.

He chose not to use the circulator and keep the system original as a gravity system..

I know it's confusing with all the banter going on but it is his choice not to use the pump.

Not complicated but confusing if you're trying to keep.

Hope this helps a little Z.
Old 01-21-18, 04:27 PM
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Well I was not up to date here, thanks Vermont and spott.
Old 01-21-18, 08:23 PM
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Life has a funny way of teaching us lessons and presenting us with challenges at the oddest times! And what time could be odder than in the midst of a pretty routine succession of posts on a website? But apparently it was not quite routine enough to suit the moderator, who found it deviated from his personal preferences-- he evidently likes posters to report, "Just the facts", and report them in way that's as colorless and boring as possible, with the poster making sure he strips all personality and individuality from his words. In fact the moderator took such exception to this current thread that he first removed my title and, without consulting me, let alone getting my assent, substituted a title of his own, one that HE considered more appropriate. His doing this was, I can CONFIDENTLY assert, a completely illegitimate act on the part of that moderator, Pjmax-- an abuse of his authority as a moderator, and was utterly contrary to the policy of this website. Why can I CONFIDENTLY assert that?

Because this is not the first time Pjmax has violated the website's guidelines in just this way!! On December 19, 2017, in an earlier thread of mine, I commented-- less in anger than amazed amusement-- that the title of that thread had suddenly been drastically altered. The Super Moderator, lawrosa, immediately posted a comment in the thread, first quoting my comment and then responding. Here's Super Moderator lawrosa's post, in its entirety:

12-19-17, 08:05 PM #25 (permalink)
"Yes, somehow I had inadvertently violated management’s highly developed sense of decorum by using as my subject line, “Converting FROM gas TO oil? Am I willfully ignorant? Crazed? Or simply stupid?” Today, lo and behold, I see that my subject line has been ‘adjusted’ to read “Converting from gas to oil? Am I willfully ignorant?”-- I guess management is concerned about any crazed or simply stupid people in the membership being offended, even though I was strictly referring to myself!"

That shouldn't of happened.. Are you saying your title was changed??? Thats a no no AFAIK here on the forums... I will look into it...

lawrosa did indeed look into it, and he actually induced Pjmax to apologize to me:

12-19-17, 08:19 PM #26 (permalink)
My apologies. The title has been changed back to what you originally posted.

And obviously, Pjmax's apology was utterly insincere, given the recurrence of the identical behavior last night.

And in fact, in his latest outburst, Pjmax has gone on to rebuke me for departing from his particular favored style-- because I had the audacity to include 'frill' and 'fluff' and 'backstory' in my posts-- and then to threaten me with the ominous-sounding words, underlined and in red, "You've been warned."

Why am I making a 'big deal' out of the behavior of a moderator on a website, behavior which people may acknowledge is arrogant, high-handed, violative of individual rights and freedom of expression, and against the very policies of the website he's moderating, but isn't it 'trivial' after all?

Trivial???? Haven't we all learned in recent months with the #Me Too movement that nothing is more important than speaking up immediately and loudly and to every relevant person in authority whenever we observe-- or learn about-- someone's rights being infringed, and above all the person who is the object of this abusive behavior should speak up for themselves-- speak up even when the first act of abuse is 'trivial'. Silence equals acquiescence, and acquiescence means that what might have been one instance of minor abuse one time against one person balloons into a thousand instances of horrific abuse over decades against hundreds of people. Harvey Weinstein could have-- and should have-- been stopped the very first time he put his hand where it didn't belong. If he had been, hundreds if not thousands of women would have been spared.

So no, it's not trivial. And so I say to Pjmax, I read your words, underlined and in red, "You've been warned" and I reject your warning as utterly unwarranted. Instead, I turn it around and say to you, "YOU'VE been warned, Pjmax!!! Your censoring of my title and your ominous warning to me is an abuse of your authority as a moderator-- it certainly won't be heeded-- or tolerated-- by me, and I hope that the highest echelons of this website won't tolerate any of the behavior of yours discussed in this post. And I further warn you, Pjmax, that copies of this post are being sent to all relevant people at DIY, and, if necessary, outside of DIY. Your reign of abuse is over."
Old 01-21-18, 08:31 PM
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No latest craze. The thing is we can smell problem members from a mile away and you have just shown your true colors.
Old 01-21-18, 08:43 PM
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My warning was to other members that were replying to your other threads with un-needed comments. DIY is a help site..... not a blog site. You've turned your threads into long winded blogs.

This thread is closed until the administrators make a decision.
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