Joined on January 21, 2007
Last Post on December 9, 2013
@ December 9, 2013 8:36 AM in modify L408B Vaporstat to "break" on pressure?Keep an eye on Ebay, as they do turn up occasionally. You can enter a search and they will email you when one becomes available for sale.
I would not use anything but a mercury switch with a millivolt system. With such a low voltage, high current circuit, contact resistance becomes critical. With the typical dry contacts of a microswitch, any oxidation can increase the resistance to a point where the system may become unreliable.
Stick with what you have until you can find a proper mercury switch control
@ December 7, 2013 8:20 AM in Frog Tape and IR ThermometersI have wondered about his myself. Aside from the artistic aspect, the only thing that I could think of is that the curved spokes allow for a little "give," or flexibility compared to a straight spoke.
When the wheel is cast, there may be unequal contraction as the metal cools, causing stresses to be placed on the spokes. With the curved spokes, the stress may be reduced because they are more flexible in the same way as swing joints in piping, which allow for expansion and contraction.
@ December 5, 2013 5:33 PM in High Humidity/Boiler Leak?There may be more than just steam escaping into your basement. You also may be getting combustion gasses backing up into the basement if the chimney flue is clogged. This could be contributing to your humidity problem as the combustion exhaust gas contains a large amount of water vapor.
This could be a very dangerous situation and it makes sense to check the chimney
@ December 4, 2013 10:52 PM in Got an estimateWet steam is less efficient in that it carries less energy per unit mass than dry saturated steam. Water at 212F contains 180 BTU of heat energy per pound , while dry steam at the same temperature contains an additional 970 BTU of latent heat of vaporization. So if you are buying steam by the pound, you want the least amount of water as excess baggage, which you pay for but only serves to dilute the energy content.
But when you generate the steam in a boiler yourself, you are only paying for the heat necessary to vaporize the water into steam. You add the 970 BTU per pound of dry steam created and the additional carried over water goes along for the ride. The net effect of the excess carried over water ( which makes the steam "wet" ) is to increase the amount of condensate returned to the boiler. Theoretically, if the excess water leaves the boiler at 212F and returns at the same temperature, there is no net energy loss due to the "wetness". In the real world, the return piping may not be well insulated and the increased volume of condensate plus carried over water may lose some additional heat.
I hope I haven't confused you more with this explanation, but the end result of the wet steam is that a small fraction of the energy content may be lost in the basement piping. Actually its not really lost, but serves to heat the basement which may not be a part of the living space.
@ December 4, 2013 8:35 PM in What's the difference between a warm weather shut down and an outdoor resetYes, the Tekmar provides both ODR and WWSD functions. It also has the ability to be used with indoor temperature sensors if desired.
Here is a link to the operation and installation manual which goes into detail regarding how to set it up and indoor sensing:
@ December 4, 2013 5:02 PM in What's the difference between a warm weather shut down and an outdoor resetBoth of these terms relate to a steam system controller which depends on outdoor temperature to control the boiler. They are both typically incorporated into the same control unit and function by means of the same outdoor temperature sensor.
Warm weather shut down ( WWSD) is a function which shuts down the boiler whenever the outdoor temperature rises to a preset level. This would typically be a temperature where heat is no longer necessary, say 55 to 60 degrees.
Outdoor reset (ODR) is a function where the length of the steam cycle is varied according to outdoor temperature. For example on a 20 degree day the boiler may run each hour for 30 minutes and then shut off. On a 50 degree day the boiler may operate only 10 minutes each hour. As the outside temp changes, the cycles change in length, calibrated to the characteristics of the building. Typically there is no indoor thermostat at all, although some systems may allow for some indoor temperature sensors to avoid overheating.
Keep in mind that these systems will not even out the heating in the various apartments. If some are too cold and some too hot this problem will be unchanged. Typically the system is set to satisfy the coldest apartment and the hotter ones can turn off radiators or use thermostatic radiator valves to limit room temperatures.
The Tekmar 279 is a controller which performs these functions and has been highly recommended, although it is somewhat expensive compared to a regular thermostat
@ December 4, 2013 9:15 AM in Got an estimateRealistically, you will not see anything near a 25% savings in fuel costs just from boiler repiping alone. You just can't violate the laws of physics.
In order to save 25%, you would have to be losing 25% of the energy transferred to the steam. So where is this energy going and how could you reclaim it?
First, in a properly operating boiler, about 20% of the heat energy is lost up the chimney with the exhaust gasses from combustion. This is a given that you can't do anything about. You lose a few percent from heat loss through the jacket of the boiler which heats the basement. So realistically, you may transfer 75% of the heat energy of the fuel to the steam. This is a given and has nothing to do with the piping.
Now, you want to transmit this energy to the radiators. This is where the piping comes in. To minimize heat loss, you insulate the piping, which you have already done. Changing the configuration of the boiler piping will not change the heat loss, or the amount of heat delivered to the radiators.
If some of the radiators heat better than the others and the heat is uneven, then the efficiency may suffer because the system burns longer to satisfy the thermostat. This is more a function of the venting than the near boiler piping.
While repiping may solve some problems such as the water hammer, fuel savings is not going to be significant. You may save a few percent, but certainly not anywhere near what you seem to be expecting.
@ December 4, 2013 12:07 AM in Got an estimateYour boiler piping is far from optimal, but don't expect miraculous fuel savings from just changing the piping. There is a lot more to reducing heating costs than just that.
How large is the house, how well is it insulated and how well has the boiler been maintained? These are probably more important factors to consider in determining if your heating costs are reasonable and how much they could be reduced.
How well does your system operate now? Is there water hammer etc? If your only problem is that you believe the costs are excessive, honestly I don't think that you will save anywhere near what you are proposing to spend on repiping.
If it was my system, I would wait until boiler replacement was necessary and then redo all the piping at the same time.
@ December 3, 2013 6:33 PM in Need Help With an Old BoilerIt sounds like you have a White Rodgers mercury flame sensor. I don't think they are still available anywhere and you may have to change out the entire gas valve and pilot assembly.
You might post your question in the Gas Heating section of the forum. Tim McElwain has vast experience with these type of pilots and can advise you on how to best proceed.
Unless you find an older tech to check your boiler, he may have never even seen one of these before as they were discontinued years ago.
@ December 1, 2013 7:28 PM in Midco Low-Nox Burner Performance ReportBringing in outdoor air to the burner may increase overall heating efficiency of the conditioned space by reducing air infiltration into the building, but it won't increase the boiler's combustion efficiency.
Cold air entering the combustion chamber will decrease the gross stack temp because you are starting from a cooler baseline, resulting in a cooler combustion temp, not because more heat is extracted from the fuel.
The important factor in calculating efficiency is the net stack temp, obtained by subtracting the inlet combustion air temp from the gross stack temp. When you do this, the inlet air temp becomes irrelevant, as it cancels out any effect of the combustion air temperature. This subtraction is automatically done by a combustion analyzer when it calculates combustion efficiency.
@ November 27, 2013 8:09 PM in Boiler T&P valve dripsAs the system heats up the pressure will increase because the volume of water contained within it increases with temperature. The expansion tank provides a place to store the additional volume, but because the volume of air must decrease, it is compressed and the pressure rises.
At max temp, the pressure may increase to 20 or 25 PSI, but must remain below 30 PSI to prevent the relief valve from opening.
Precharging the tank allows it to contain more air volume at the static pressure, so it can accept more water without exceeding the 30 PSI limit.
@ November 27, 2013 4:07 PM in Boiler T&P valve dripsIf the system pressure is remaining at 13-14 PSI and the valve still leaks, the valve is bad, or has dirt on the valve seat causing it to leak. You can try raising the manual release lever to flush out the valve and see if it helps.
The valve is designed to release at 30 PSI and should not leak at all before that pressure is reached.
@ November 27, 2013 3:39 PM in Temp of Cast Iron RadiatorUsually, systems are designed for a max water temp of 140 to 180 degrees. So on the coldest day the system was designed for (design temperature) the radiators might approach those max temperatures, but typically under normal conditions it will be much less.
@ November 27, 2013 3:29 PM in Temp of Cast Iron RadiatorA cast iron radiator in a hot water system should only be as warm as necessary to meet the heating load at a given outdoor temperature. Since this type of radiator has a high thermal mass, it takes a long time to heat up but then it continues to give off heat long after the boiler has stopped firing.
If the system is maintaining a constant indoor temperature at the thermostat setpoint, then the radiators are as warm as they need to be.
On a mild winter day, an 80 degree radiator temperature would not be unusual. I think you will find as the outdoor temperature gets colder, the radiator temperature will increase as necessary to maintain the indoor temperature at the thermostat setting.
@ November 26, 2013 11:12 PM in Oil to Gas conversion 2 pipe steam system low heatWhen you said that the system shuts down prematurely, do you mean the boiler stops firing when the thermostat is satisfied, or when the cutout pressure of the pressuretrol is reached?
How long does the boiler fire before it shuts down and does it continue to cycle on and off?
@ November 26, 2013 10:55 PM in Oil to Gas conversion 2 pipe steam system low heatWas the thermostat changed when the boiler was replaced? Is it a newer type digital or the older analog type.
If you have the older style thermostat, the anticipator will have to be readjusted for the difference in current draw of the gas control valve compared to the oil primary control.
@ November 26, 2013 6:17 PM in Burner retrofit for scotch boxThe Gordon Piatts are a good burner, and I would doubt they are the cause of your problem if they are set up properly. As Dave mentioned, most of the parts are standard off the shelf items and the other proprietary one are still available.
I am running three 80 Hp Scotch Marine boilers with dual fuel Gordon Piatt burners, and they have been all working at 85+% combustion efficiency for more than 10 years. We have no plans on replacing them any time soon.
High stack temps are more a function of the boiler itself and its heat transfer characteristics, rather than the burner unless you are overfiring.
@ November 22, 2013 9:42 PM in too high steam boiler pressureThose two small valves behind the sight glass are try cocks used to check the water level. If you open the bottom one you should get water out, while opening the top should give you steam. This tells you that the water line is somewhere in between them in height.
The boiler may not have originally come with the glass and the valves may have been the only method to check the water level in the boiler.
@ November 18, 2013 9:16 AM in BURNHAM BASE- RAY & One-Pipe Steam SystemJoe I am not sure I understand you correctly, but the condensate drain at the opposite end of the Baseray does not need to drop 30 " if you are returning to the bottom of the main. The only pressure differential the drain end will see is the difference between the two ends of the radiator, not the full boiler pressure.
@ November 15, 2013 11:03 PM in What to buy. (replacement circulators)How is the burner being controlled at the present time? Is it maintaining constant temperature under the control of an aquastat, or does the burner only come on when one of the zones calls for heat and the circulator runs?
If you are maintaining constant 180F at the boiler and just controlling the circulators with the thermostat, it is certainly understandable why you are getting the extreme swings in room temp.
You would be much better off if the aquastat only maintained a minimum boiler temp of 130F and then had the burner only fire when either zone called for heat. That way you would have the benefit of the "natural reset" Ironman mentioned and much better control of room temp.
@ November 15, 2013 9:32 PM in Radiator Gives No HeatIt sounds like you may have a steam heating system from the banging sounds you described.
If so, you might get more responses and advice if you post your question in the Strictly Steam section of the forum
@ November 15, 2013 10:29 AM in Water clarity for steam boilers - how clear should it be?Really what you are doing is producing distilled water, so any dissolved solids in the condensate would probably originate from carried over boiler water