Joined on January 9, 2009
Last Post on March 6, 2014
@ March 6, 2014 1:13 PM in TT PE110 longer run times"I am trying to do the same thing
but not only are you tweaking outdoor reset but you also have to factor
in the boiler pump vs system pumps for my system at least. So even if
your tstat is still calling, you may reach set point quickly."
If you reach the set point quickly, your supply temperature is too high. You want it to be just a tiny bit higher than what is required to maintain the temperature. So you adjust the reset curve accordingly. If you cannot do that, it is likely that your boiler is oversized.
"If all of my zones are calling, the boiler is fine but if one tstat gets
satisfied, the burner can not modulate down fast enough and hits its
setpoint and shuts down. "
How long does it take to modulate down? Mine will do that in well under two minutes. Is it a question as to how fast it will modulate? Or a question of whether it will modulate down far enough no matter how much time it is given?
"I also have pulse width modulating tstat for my radiant heated slabs
that also can affect burn times, the closer to the setting, the shorter
the burn times like 10-12 minutes."
For radiant slabs, it seems to me the best thermostat is a simple on-off one like the old round mercury-filled Honeywell ones. but they are not the only ones.
"How long are your burn times and how much delay are you running for your burner?"
Today, and is is not terribly cold outside (25F), my radiant slab zone has been calling for heat for 9 hours 24 minutes since midnight. Chances are it fired continuously for that time, but I did not go out to the garage, where the boiler is, to watch it the whole time. When I do watch it, it tends to run continuously when the zone is calling for heat. (It is a different story when only my small baseboard zone calls for heat, because the boiler will modulate down only to 16,000 BTU/hr and that zone needs only 6250 BTU/ hour when it is 14F below the design temperature. So my boiler is way oversized for that one zone. Even in that zone, though, it promptly modulates down to the lower limit and wanders up to the upper limit, about 4 to 6 cycles per hour, depending on outside temperature.
@ March 6, 2014 12:57 PM in computer room heat gain questionI do not know about when sitting, but when working about as hard as he can, a human can put out about 1/7 horsepower. I do not know if he can do that hour after hour or not. But that should get you into the ballpark.
@ March 5, 2014 8:17 PM in TT PE110 longer run timesTo get the longest run times, use the lowest supply temperatures you can get, consistent with being able to achieve the temperatures you want. This involves setting your outdoor reset curve correctly.
I have a radiant slab at grade. My design temperature (outside) is 14F, but this year it got down to just under 3F a couple of times. With my 1150 square foot Cape Cod here in New Jersey, and trying for 69F inside, I supply 76F water to the slab until it gets down to 50F outside. I then let the supply temperature to increase in a straight line until it gets to 0F outside and the supply temperature is 128F.
With that, the run times get shorter and shorter as the outdoor temperature increases. but when it is under 50F outside, I get run times of 10 to 18 hours sometimes. I could squeeze it a little bit more but then it responds to changes in outdoor temperature too slowly. As it is, I cannot get the indoor temperature over 70F by changing the thermostat setting because the supply temperature is not high enough.
There is no secret, really. Just weeks of boring set and test. Because with my slab, it takes about 24 hours to really stabilize the heating again after making a temperature change. (So forget about setbacks).
@ March 4, 2014 11:26 PM in Ultra 155I do not think the design W-M supply for near-boiler piping is antiquated. It seems to be quite similar to what John Seigenthaler shows in his big book. In any case, I have never had any problems with the piping other than a ball valve whose bonnet needed tightening after a few months of operation, and a noisy circulator that needed to be replaced under warranty.
It might matter which W-M Ultra series you have. I have an Ultra 3 80, and I have read the Ultra 2 manual, though I no longer have a copy. Their piping diagrams were pretty much the same, if I remember correctly. W-M now make newer models that they do not call Ultra 4, and they seem about the same for piping as the Ultra 3s.
My installing contractor did a couple of things right. One was that they used 1 1/4 inch piping in the boiler loop, where for my model W-M said it must be at least 1 inch. This got the flow speed through the microbubble resorber to be lower.
The other thing they did was that W-M said the closely spaced Ts should be no more than 12 inches apart, but they put them 5 inches apart.
@ March 4, 2014 12:05 AM in in floor radiant problemI am a homeowner, not a heating professional. But it is fine with me if my radiant slab zone (5 loops, not one the same size as another) takes 12 to 18 hours to heat. And when it is quite cold outside, it does. It does not matter to me how long it takes because for that zone; my mod-con boiler just modulates down to the supply temperature needed. If I were attempting setbacks, that would not work, but it makes no sense to me to use setbacks on a radiant slab at grade heating zone anyway.
I am not sure what you mean by an open direct system. Do you mean one that is not pressurized? And by direct, do you mean that there is no heat exchanger other than the one in the boiler?
If your other zones are also radiant slab zones, I find it impossible to believe you can make significant temperature changes to a zone in 15 to 20 minutes unless you run extremely hot water in them, and if you did that, you could burn your feet walking barefoot, and you would get enormous overshoot after your thermostat was satisfied.
In my system I can run 76F supply water into my slab and satisfy my thermostat provided it is over 50F outside. At 14F outside (design temperature), I need 114F supply temperature, and at 0F, I need 128F supply. With 76F supply, it looks like the delta-T is zero, but since it heats, it must be a little more than that, but it sure is less than 1F. With higher supply temperatures (when it is colder out), the delta-T is greater of course.
@ March 1, 2014 4:52 PM in A challenge...I had two Weber 40 DCOE's on both my Lotus 26's from the early to mid 1960s. They had a reputation for being difficult to adjust, but they were actually very easy to adjust, if you understood them and had a synchronizing tool. The only thing I did not like is if the butterfly valves (the ones hooked up to the gas pedal) in a single carburettor were out of synch. You had to put a wrench at each end of the shaft and twist it. Scary. They really needed very little adjustment.
But running an oil-fired heating boiler would be simpler than running a car engine. It would need no butterfly valve, no acceleration pump, no choke (well, Webers did have a choke, though you could not see it because it worked very differently from the others.
Those SU carburettors could, in theory, provide exactly correct mixture at all times, but they did not because the least amount of dust or dirt could impede the movement of the piston in there. and it was right in the air stream, so dust was always available. And if a mechanic was dumb enough to put oil on it, ... .
@ March 1, 2014 2:09 PM in A challenge...Remember in the old days when automobile engines used carburettors to mix the gasoline and air for combustion? It turns out that the mixture must be pretty much of a constant (I forget the ratio) over the entire speed-power needs of the engine from idle to maximum acceleration up a hill or anything in between. And they could do it. Now oil is more viscous than gasoline, so you would not use an automobile carburatter to run a modulating heating boiler..
The best ever automobile carburettors were made by an Italian named Eduardo Weber. And he started designing these thing to enable heating type oil to be burned in automobile engines. I do not know how well that worked, but they worked great on gasoline.
The main control of the fuel available to the engine was the disk in the throat (venturi) of the carburettor. For a heating boiler, I assume a variable speed fan would be used instead, since there are no pistons going up and down to power the air flow. Now in a venturi, the air flow mixture ratio is not right to maintain a constant mixture, so what is done is to bleed air into the gasoline mixture as it passes through the unit. This is done with a secondary jet in the gasoline stream with holes in it at various levels.l But in any case it can be done. So perhaps a similar technique could be used in the "carburettor" of a heating boiler.
@ March 1, 2014 1:48 PM in Switching from Oil to Gas1.) Did any of those contractors do a heat loss calculation?
2.) Did any of those contractors measure the emission of the heat emitters (the baseboards)
3.) Do any of those contractors know the design temperature of your neighborhood?
4.) Did any of those contractors ask you if you would consider increasing the size or effectiveness of the baseboard units you have?
Because if they did not, they do not know what they are talking about.
It may be that a mod-con boiler is not for you.
But what if the time your system spends heating and the outside temperature is considerably above the design temperature, and your baseboards are larger than necessary (perhaps because originally overdesigned, or because you improved the windows, insulation, outside air infiltration, it just might be that you could put low enough water into your baseboards to get condensation a lot of the heating season. And even if you do not, perhaps you would be willing to increase the size or type of baseboards so you could get condensation a lot of the time.
And even if you do not get condensation much of the time, the fact that the boiler modulates down will get you an efficiency increase because the flow of heat from the fire side of the heat exchanger into the water side is increased as that difference increases.
@ February 26, 2014 11:19 AM in How many of you carryIf I remember high school chemistry correctly, all gasses at the same temperature and pressure weigh the same.
But in particular for these two gasses, they would certainly be the same because Avogadro's law states that, "equal volumes of all gases, at the same
temperature and pressure, have the same number of molecules"... Now the molecule of CO weighs 12 + 16 and "molecule" of air that is 80% nitrogen weighs 14 + 14. So they are the same. Actually, since air is 20% oxygen, would weigh a little more (16 + 16), so air would settle. Except for one thing: If they were all at the same temperature and pressure, they would be thoroughly mixed regardless of the weight of the molecules because unless the room were at absolute zero, the thermal energy of the molecules would keep them completely mixed.
@ February 25, 2014 1:54 PM in Gasoline from Natural Gas?Yes, but what will they do with the cheap gasoline? I doubt they will put it in small bottles to exhibit in science museums. My bet is that they will mostly burn it in internal combustion engines, causing even greater environmental damage and climate change than we are already doing. And we already cannot stand the flooding in out of the way places like Norfolk VA, Virginia Beach, and the droughts in other distant lands, such as the wilds of California. This is not a far-away problem for the next century. It is here now.
It seems to me that if we have too much methane (mostly from natural gas) it is better to burn it in something like a furnace or boiler than to let it escape directly into the environment. Methane is apparently 10x to 20x worse as a greenhouse gas than is carbon dioxide. But do not waste the energy produced by adding the process of converting it from gas to gasoline. That just makes matters worse.
@ February 25, 2014 11:47 AM in any risk associated with a properly executed TSP cleaning?My boiler has an aluminum heat exchanger (hot water, not steam) so I cannot use TSP in it.
However adjusting pH can be tricky, depending on what is in the water already.
If the boiler water were too acid, one might put in some sodium hydroxide (preferably already in a solution of known concentration. Now if the water in the boiler was just plain water, and you wanted to raise the pH of the boiler, the amount of sodium hydroxide could be calculated as you described.
And if you went too high, you could titrate it back with hydrochloric acid.
But there are solutions, known as buffer solutions, where they resist (within limits) any significant change in pH.
For example, a solution of disodium phosphate and sodium hydroxide wants to hold a pH of about 11.5/
A solution of sodium bicarbonate and sodium carbonate wants to hold a pH of about 10.2
A solution of boric acid and sodium hydroxide wants to hold a pH of 9.2.
Now if you put lots of acid into a solution, the pH will eventually go down as the existing mixture is changed.
I would imagine those who sell chemistry for adjusting boiler pH actually supply buffer solutions so that the pH does not change for a longer period of time that a simpler solution would.
@ February 25, 2014 10:57 AM in navien and odr?"I was a bit surprised to see a condensing boiler sold without ODR in the
box. After doing a training on these boilers I can see that they are
kind of dumbing things down for the American market, they seem to want
to keep it simple and make this boiler an easy swap for a conventional
I guess they do want to keep it simple, but they do not keep it simple enough.
When my mod-con was installed, the lead technician did not want to install the outdoor sensor, because it did not make any difference. Since it comes in the box with the boiler, I insisted that it be hooked up.
I had read the entire installation manual. So I was quite surprised that he used all factory defaults for the setup. I have an indirect across the supply and return of the boiler, and two heating zones that require different reset curves. The controller readily accommodates this, but he did not know how, so I told him. He also had no idea how to set the reset curves, even though it is explained in the manual, and there are no funny codes or anything: everything in plain English.
I figured out why he said outdoor reset did not make a difference. They tried to sell me an oversized boiler (they did not calculate the heat loss), and if I had taken their advice, the boiler would have come off the minimum firing rate only when the outdoor temperature was considerably below the actual design temperature.
So my boiler was not dumbed down enough for that technician, who also had no combustion analyzer. He did not need one because they are preset at the factory (or so he said).
Some contractors should not be selling mod-con boilers because they are too dumb to install or service one.
@ February 22, 2014 9:01 AM in Will boiler/pump still work if both zone valves are closed?I am not an attorney, but in some jurisdictions, it would be illegal to turn off the heat unless doing so still ensures that the apartments attain at least the legally specified temperatures. So even if you can technically turn the heat off at night, you might get fined for violations.
@ February 20, 2014 10:52 PM in taco zone relay constant hum soundThe funny thing about that toroidal ferrite core transformer in my stereo amplifier is that they make a big deal at how much better sound it delivers because of that transformer.
But that fancy transformer is the power transformer, not in the output (it is not a vacuum tube amplifier and does not require an output transformer for each channel). It very probably has much less leakage of magnetic flux, and may well not hum. But other than that, I do not see why they make such a big point of it.
Now I do not know what kind of transformer Taco uses in its relay boxen, but it does not look like a toroidal ferrite core one. But would the majority of customers pay the extra cost of a ferrite core transformer? I very much doubt it.
@ February 20, 2014 7:53 PM in taco zone relay constant hum soundThey do not have to hum. But when they are built to sell for low prices, they will.
Most cheap transformers designed to run at power line frequencies are copper coils around a steel core. The core is made up of laminations of stamped steel sheets.These sheets are lacquered so as to be electrically isolated from one another. If the right grade of steel is used, their magnetostrictive properties are very small and they produce little or no noise. Magnetostriction is the name for a material changing size in the presence of a magnetic field. So if they pick the best grade of steel, there should be next to no hum.
I have a stereo power amplifier that went another way. Instead of using the laminated steel sheets, they used a ferrite magnetic core. It is pretty easy to use the right composition of ferrite practically eliminate magnetostriction, and thus eliminate the hum. But winding a ferrite core is more labor intensive (read: costly) than pushing in the steel laminations. So you will never get a quiet transformer. But you could if there were sufficient demand to pay for it.
@ February 6, 2014 11:55 AM in Parallel Tempering Valve AdviceMy first hand experience with a very fancy one by Lawler is the basis for my opinion. They used to make such valves for photographic darkrooms where it is desired to hold the temperature to +|- 1/2 degree. And they come in various sizes. Mine is the smallest, and regulates from 1/2 gpm up to about 3 gpm. The ones most used regulate from about 2 gpm to 7 gpm, and larger ones were available. I do not think they make any of these anymore.
Mine is pretty much like this one, but this one is the next larger size:
My unit has a check valve at the hot input, another one at the cold input, a vacuum breaker at the valve output. Inside, the hot and cold go to a pressure balancer and from there to the temperature regulator. This has a big knob for you to set the temperature. It goes around about 3 full turns. At the output is a large temperature dial that you can easily read to 1/2 degree. Now when I need accurate temperature, I must run it at 1/2 gallon per minute or a little more, or it does not hold the temperature. the valve (especially the pressure balancer) needs a pressure drop through it to activate that, and and lower flow rates, it does not get it. And if the pressure balancer is too far off, the temperature controller cannot move far enough to compensate. If they made a valve from 1/4 gpm to 1 1/2 gpm, I would be much better off. They still make shower valves.
@ February 3, 2014 2:31 PM in Congress seeks to jack up fees on home heating oil in midst of frigid winterAmory Lovins, a well-known environmental activist and author, was asked how he could justify cutting down trees to burn in his heating stoves. He replied that he did not cut down trees for that. Well, what does he burn in the stoves. His reply was that he burned energy studies.
With that 959-page bill, you should ask your congressman to send you a copy of the bill every few days and burn it in your fireplace, wood burning stove, etc.
@ February 3, 2014 8:11 AM in Hot water baseboard heatingIn my house, with a mod-con heating a radiant slab at grade, and some oversized baseboard heating the other zone, changing the temperature one degree in the radiant zone takes about 24 hours, and in the baseboard zone, at least 4 hours.
This is not because of the fact that anything is under radiated, but because the way the system is designed and programmed. Actually, the boiler is about twice as big as it needs to be and I could heat this house to just about any temperature I want it to be, as long as I do not mess around with the settings.
The reason I can raise the temperature so slowly is because the outdoor reset is programmed to provide only a tiny bit more heat than the heat loss (and this excess only to deal with imponderables such as higher than normal wind and resulting infiltration, and lower than normal heating from the sunshine).
My boiler does have a boost feature where if the load is not satisfied in a certain period of time, it boosts the supply 10F and tries that. If the time expires and it has still not satisfied the thermostat, it boosts the supply another 10F, etc., until it does. There is a limit to how much it will boost the supply temperature. But to run the system normally, that boost interval needs to be a couple of hours in the baseboard zone, and over 12 hours for the radiant zone, so I just abandoned the idea of using setbacks at all.
As a homeowner, I conclude that if you want to make the outdoor reset work best (at least for a mod-con), you do not want to run setback at all. Get your efficiency from the reset (and condensing), and forget about setbacks. If you want your bedroom cooler than the other rooms, shut the door of the bedroom and adjust the hot water flow through it to be a lower temperature all the time. I do that by partly closing the valve supplying the hot water to that room.
@ January 31, 2014 10:03 AM in Need some serious helpDo you mean like reading the I&M manual?
It seems to me as a homeowner that too many contractors hate to spoil that nice plastic film wrapper on the manuals, and it is a matter of professional pride to never look at one. I cannot imagine why that is. I am not prejudiced enough to assume that heating contractors are more dislexic than those in other professions, because other professions seem to suffer from this problem too.
When I got a new washing machine, that contractor did not even leave me the manual. Luckily, I found one on the Internet. I guess they figure the homeowner does not read the manuals either. Same thing happens with computers. I think too many people are functionally illiterate. They can pass enough tests to get out of 8th grade, but they cannot read an instruction booklet, or at least, they refuse to.
@ January 26, 2014 4:30 PM in New boiler, Insufficent heatI am sorry I was unclear.
"Do you mean without outdoor sensor the boiler will not prioritize the
call from room temperature , instead it will prioritize the hot water
No, I did not mean that. I meant that the boiler will continue to use the priorities, with priority #1 to be the most likely to run, then priority #2, then priority #3. And by default (and I see little reason to change it) priority #1 is for the Indirect, priority #2 is normally used for the first heating zone, and priority #3 can be used for another heating zone.
Each has its own reset curve (although the indirect does not actually reset).
What I meant was that if you do not connect the outdoor sensor, the boiler assumes it is maximum cold outdoors and puts out the hottest temperature that the reset curve associated with that particular priority provides, irrespective of what the outdoor temperature might be.
"yes, he limited hot water heating to 6-7 min each time."
For my boiler, which is oversize (it is the smallest Ultra 3 there is), so I have no trouble getting enough heat. I live alone, so my hot water needs are modest. I allow the top priority indirect hot water heater to run up to the default of 30 minutes because I have never seen it run over 15 minutes anyway, and it runs only twice or perhaps three times a day, so it does not matter to me if it steals this from heating the house. I figure I might as well let it restore the maximum.
"But I will relay your post to him to get outdoor sensor installed."
Go ahead if you like. What would worry me is that if he needs the contents of my post, it almost certainly indicates that he did not read and understand the installation manual. The contractor who installed my Ultra 3 had the same problem. It seems a matter of honor to not read the installation manuals. Maybe that works for coal fired convection hot air furnaces, but is sure does not work for mod-con boilers. It was a real surprise to find out that I knew more than the installing contractor did about the boiler they sold me.
"I thought the purpose of outdoor sensor is really to get the heating system shut down when outdoor temperature gets too high."
Not really. It does do that; that feature is called Warm Weather Shutdown, that will turn home heating off, but leave the boiler alert when the indirect needs heat. The default warm weather shutdown temperature for the Ultra 3 is 70F outside temperature.
But the main purpose for outdoor reset is so that the boiler will put out the minimum possible heat consistent with keeping your house warm enough. With the outdoor sensor connected, and the reset curve properly adjusted you almost do not need an indoor thermostat at all. As it gets colder out, it increases the supply temperature of the water to the radiant floors (if you have them) or your baseboards, panel radiators, etc. As it warms up outside, it reduces the supply temperature and the house keeps the temperature you want.
If you have a high mass system (one of my zones is slab at grade radiant), this keeps the temperature very even with no overshoot or undershoot.
But the main advantage is that the lower the supply temperature, the more efficient the heating of the water is because the difference between the fire temperature and the water temperature is greater, and so the heat flows into the water that much more efficiently. A secondary advantage is that the lower the supply temperature, the lower the return temperature will be, and if it is low enough, the exhaust will condense and give you up to about 10% more efficiency than if no condensing were occurring.
@ January 26, 2014 2:45 PM in New boiler, Insufficent heatIt will run at the maximum temperature end of the boiler reset curve for whatever thermostat input is in effect (the highest priority one; i.e., the one with the lowest number that is calling for heat). The highest is usually #1 that is by default, an indirect hot water heater.
The next highest is usually #2. And what circulators are running depends on how the control is programmed. Normally, input #1 runs only the circulator to the indirect. Normally, input #2 runs both the boiler circulator and one of the system circulators. If it is set up wrong, it might run only the boiler circulator, or it might run only one of the system circulators. Both would explain cold results.
@ January 23, 2014 8:09 AM in Radiant Heat in the NorthwestDo not count on it. I am in New Jersey, where the design temperature is 14F. However this year, it has gone down to much less: just under 3F twice, and just under 7F last night. When it does that, the floors do get warm. If it goes down to 0F outside, I put 128F water into the slab (you may not want to go that high if you have hardwood floors). At 14F (design temperature) I put 114F into the slab. The surface temperature is less than that, of course. Sometimes the floor is pretty cool, mostly it feels like it is room temperature, and now it feels warm. That is for a concrete slab at grade.
I happen to like radiant heating, and if you have a slab at grade, it is nice to have it take the chill off the floor. But do not count on it being warm to the barefoot touch except on very cold days.