gas steam boiler heating problem

montek

hello to all. I have a pretty old Dunkikr Bpiler- I believe I have steam heat from a gas boiler. My model number is 235AAW007112AADA and the serial number is 3685V01918. I know you are going to say it is really old- BUT it has


been tried and true for all these years. On occasion, we get knocking in the pipes and when that happens I drain the water and lower the sight glass level of the sight glass until the red cut-off light goes on. Then I refill the sight glass to the manufacturer's level. Just recently the kitchen radiator gave out a huge metal knock and we saw water pouring from the vari-valve(air vent). We had a plumber come over and he changed the vent and flushed and cleaned out the boiler.here is what was done---------1/29/24- cleaned gauge glass, pigtail, calibrated pressure troll, and tested lwco. System is running. Water level and boiler keeps
fluctuating to the point where it shuts off the low-water cut-off. After several minutes the water level rises back and satisfies low-water
cut off turning the boiler back on. This repeatedly happens. Turned on the basement hot water loop and everything seems to be functioning
properly. Recommending to the customer first to balance the system with new vents and to locate the main vent in the basement. Need to look in the soffit
as it seems that the return line starts about halfway across the basement. That is were we stand now-- But after all, this was done- The kitchen radiator with the NEW air vent is NOT heating up. But my other concern is that the NEW water level on he boiler is ONLY about 1" from the bottom of the sight glass. And thus when the heat goes ON it brings the water level below the sight glass and the cut-off switch is engaged and the boiler shuts off after being on only for about 5 to 6 minutes and stays off for about 4 minutes then starts all over again until the home is heated to where the thermostat was set to. But the water in the sight glass is SO much lower than the manufacturer recommends. mentioned the water level was Always the NORMAL height.
cdn.net/5021738/uploads/editor/ef/l9ewzea9de1p.jpg" alt="" />
Please let us know and thank you for your time.

Big Ed_4

Yes, the header is piped wrong , it should be piped with using two taps from the top with an equalizer to the Hartford loop .

realliveplumber

Copper is not used because of the expansion issue.

The price of copper has nothing to do with it.

Jamie Hall

Well, as noted the boiler is piped wring, and with the wrong material, and your plumber is wrong about the reason -- it's because black pipe, which,, incidentally, was used long before copper -- doesn't expand as much. Black pipe isn't used by some plumbers because they don't want to take the time and care to use it -- copper is easier and cheaper to install.

It's worked at least until no because steam is really quite forgiving -- most of the time.

Now. The water level. It should be kept at least in the middle third of the sight glass -- perhaps biased a little towards the top. How is water fed to the boiler if it needs it? Do you know if there is an automatic water feeder? Perhaps you could take some more pictures of the boiler from all three accessible sides, showing more of the piping? So we can see how water is added to the boiler? If you have a manual feed valve, which you seem to, you could try adding water until the water level was where it belonged... then keep track of the water level both when the boiler is running and after it is cooled off. Does it return at least eventually to where it was before a cycle after the cycle has ended and the boiler cooled off?

As to the radiator. That huge knock and water pouring out of the radiator...Problems. Real problems. Huge knocks are not good. But the first thing to check is whether the valve to the radiator on the left hand side is actually open. Turn the handle counterclockwise as far as it will go.

montek

I want to thank you all for your replies--- first as to a reply for Big ED-- as you can see the boiler is I think 1985?? Am I correct? by looking at the serial number on the decal? and since it is piped wrong- do you think it is worth redoing the piping OR just buying a NEW Dunkirk Boiler? I think from looking at the site it is PSB Gas/steam Boiler?
As for the reply from reallive plumber- I guess if I can fox this boiler, I can LEAVE it copper??
As for the reply from Jamie Hall--It has a manual feeder which is a valve that you cannot see since it is behind the large pipe going vertically. When the water level was low in the PAST I would manually **** water to the sight glass to bring it to the water line as requested by the manufacturer. I did that very recently and the boiler still SHUT off when the red light (cut-off) switch went on. When the boiler recovered somewhat and got cooler and even cool- the water level NEVER returned to that water line- it ONLY returned to the lower level it is set now as you can see in the picture (it is only about 1 inch or so above the bottom of the sight glass (much lower than the white line on the two bars on either side of the sight glass. As for the banging - my plumber says the pipes are pitched wrong. What I am confused about is that as I mentioned we have been in the home for 30 years and NEVER had such banging every day. I know it is old but does that mean we have to do a whole new system and changing of the pipe pitch- I mean I do not want to destroy walls and have a major reconstruction of the home. is there any other way to alleviate this problem.

WMno57

montek said:

Recommending to the customer first to balance the system with new vents and to locate the main vent in the basement. Need to look in the soffit as it seems that the return line starts about halfway across the basement.

Was this done?

montek

No just one new vent was installed on the kitchen radiator and that one is STILL leaking?? The others that have the vari-vents- are all hot with no problem so I am not sure what new vents will do?? Will putting the same vents on all radiators do ANYTHING? And no, they have NOT checked the soffit area yet especially since we just had the basement redone and they now have to open up something that has just been closed up to check the return line:(

montek

WMno57

I have a hunch the main vent has failed and needs to be replaced. An inspection camera inserted through a small hole may be able to locate it. Then a larger hole could be cut, the main vent replaced, and the hole covered with an access panel for future inspection and maintenance.
The boiler, old or new, is just one component of a steam heating system. Vents fail and need to be accessible.
The plumber who worked on your system seems to be somewhat knowledgeable about steam heat. The people who told you copper is OK, don't know steam. Some of them might tell you whatever you want to hear, take your money, and your steam system still won't function properly.
If you would like to learn more about steam heating, here is a book written by the founder of this site. It is written for non technical homeowners.
https://www.heatinghelp.com/store/detail/we-got-steam-heat-a-homeowners-guide-to-peaceful-coexistence

montek

thank you-- but I do not know where the MAIN vent is? What he is talking about is the vent that leads to my daughter's room on the opposite side of the home from the boiler and upstairs as well. Her radiator NEVER heats up- I th6ought it did not because by the time the thermostat shut off in the main level it did not allow for the heat to travel all the way to HER radiator. So that vent in the soffit is the vent that leads to the upstairs level and her room only. It is for that reason that I do not know where the MAIN vent is - should I ask the plumbers if they know where it is? Also, just FYI-- my plumber right now is Dennis and Dan Scully. They told me that they are on this site and that Dan is a specialist in steam heating systems and that when someone asks for a plumber with knowledge about steam systems in Nassau County, NY- they usually send them to Dan Scully. If that is the case, then I have the right people?

montek

The reason I am confused with my daughter's radiator- is because as I stated before- I thought that instead of the cut-off switch turning the boiler off it was that the temperature in the home reached what I asked the thermostat to bring the home to and once it hit that temperature the boiler was told to stop- whether it was low on water or NOT? Isn't that the normal way it should work. Because now it only shuts off when the water level gets so low that the cutoff switch does that (remembering that the water level in the sight glass is very low to begin with). So, if the boiler shuts off as it used to by reaching the temperature, I set it to- then was that why the furthest radiator upstairs never got hot because the boiler turned off before the heat ever got there? Please explain. And thank you again for all your help. . But what I really want someone to be honest about is the following question. Should we FIX this system If that is the case, isn't it WAY beyond its years? And shouldn't we put the money into a NEW Dunkirk Boiler instead of feeding this system that is this old? Please let me know what you guys think and make sure it is from 1985? Thank you again.

109A_5

Hello @montek,

montek said:

I can LEAVE it copper??
As for the reply from Jamie Hall--It has a manual feeder which is a valve that you cannot see since it is behind the large pipe going vertically. When the water level was low in the PAST I would manually **** water to the sight glass to bring it to the water line as requested by the manufacturer. I did that very recently and the boiler still SHUT off when the red light (cut-off) switch went on. When the boiler recovered somewhat and got cooler and even cool- the water level NEVER returned to that water line- it ONLY returned to the lower level it is set now as you can see in the picture (it is only about 1 inch or so above the bottom of the sight glass (much lower than the white line on the two bars on either side of the sight glass.

My boiler (mostly 50 years old) has some copper pipes. Yes it is not optimum and can cause problems. Since your boiler is small (maybe 4 sections) and probably only one supply tapping (steam exit from the boiler) is required by the manufacture it is probably fine so the expansion issue with copper may not affect the Boiler's heat exchanger and the copper pipes on the side do not appear to be leaking where they are connected to the boiler.

You need to figure out where the water is going. With your system's symptoms, the water may be trapped in the system (where mostly steam should be) and not returning the the boiler in a timely fashion, possibly plugged condensate return(s). Also a steam leak or condensate return leak somewhere or the steam is going up the chimney. After one heating cycle the boiler's water level should return to where it was at the beginning of the heating cycle as the condensate returns to the boiler.

It seems like your plumber was trying to fix the symptoms and not finding the root cause. You need someone that understands the system and can troubleshoot it correctly or learn to do it yourself.

109A_5

Hello @montek,
The main vent (if it even exists) is usually near the far end of the Main pipe, it allows the Main steam pipe to fill with steam quickly. Then the slower vents on the radiators allow the radiators to fill evenly to give even heat to all the radiators. If you have water (condensate) trapped in the system, due to poor pipe pitch, slow or plugged returns, etc, so it won't drain back to the boiler properly, some radiators may not heat properly and other issues like hammer.

WMno57

montek said:

my plumber right now is Dennis and Dan Scully. They told me that they are on this site and that Dan is a specialist in steam heating systems and that when someone asks for a plumber with knowledge about steam systems in Nassau County, NY- they usually send them to Dan Scully. If that is the case, then I believe I have the right people?

Congratulations! You have already done what so many people who post here with problems can't do. That is find someone who knows steam heat.
If I were in your shoes, I would hire the Scully's to install a new boiler, and replace all the near boiler piping with threaded steel pipe (also known as black pipe). Then you would be done. The boiler would probably outlive you. And it would work. Be sure to have the Scully's out every September to maintain it.
You could have them patch up your old system, but how often does Picasso offer to paint a family portrait for you? 10 years from now when everyone hates their heat pumps, you could be warm!

Jamie Hall

You have two of best people you could possibly have found. Enjoy!

montek

thank you so much for the lesson- which believe it or NOT is still way out of my league. as to your first reply-- you said we need to find out where the water is going?? How does one do that (the plumber) and that the water is trapped in the system? What does that entail- ripping up walls to see all the pipes? I am confused- I want to know what to ask these plumbers if you know what I mean By the way he also checked the chimney and was looking for white smoke which he saw NONE and said if there was white smoke coming it meant that my boiler is cracked which I guess it is NOT? And also, as mentioned much earlier- the water level used to be up to that white line but now is only about 1/3 of the way up and once the boiler goes on the water level runs out fairly quickly and shuts the boiler off BUT then does return to that point fairly quickly- (BUT not to the white line only to that lower point now? So, it seems that it is recovering water quickly but just not as much as I think it should????
As per your second point- that is exactly what this plumber stated that the pitch on the pipes is wrong????But it has been this way for 30 plus years so why now is it doing this?? That is what I need to know-- is it just getting old? I know you said yours is 50 years old- BUT if I keep putting money into this how many years will I truly get out of it anyway. Or am I just beating a dead horse? See my position on this? And by my pics is my system from 1985? And being what you have been told about all my problems- what would you do? And how does one CHANGE the pitch of these HUGE pipes to fix the hammer etc.-- how big of a job is this- can you advise me on that?

montek

montek

WMno57

Your home has probably settled over the last 30 years. The condensate return pipes may also be filling up with gunk. Causing them to drain slowly and incompletely.
Drywallers and painters are a dime a dozen. You will never find steam experts better than the Scullys.

WMno57

Every pipe in the house does not need to be replaced.
The long horizontal runs in the basement do need to be properly pitched, but not necessarlly replaced.
This will be accomplished when all the copper near boiler piping is replaced with threaded steel pipe.
Replacing the near boiler piping is always done on a quality boiler install. Whether the pitch needs corrected or not.

montek

thank you to all- I truly appreciate you all.

109A_5

Hello @montek,
If the Scullys are so revered here, why is this customer seemingly worse off than before they worked on the system ??? Maybe they had a bad day. I'd call them back. You paid them to fix your system, they did not.

If the boiler's heat exchanger is not cracked or otherwise compromised and you pay for a new boiler install and then have the same problems after how will you feel ???

You need someone to actually do the needed work to troubleshoot the system, some (minimal) exploratory surgery may be needed. Houses settle, remodeling folks remove pipe supports they should not have, there is a list of issues as to what could have changed. Without being there it is all a best guess. Apparently the plumber was guessing too, hopefully he eliminated a few things like a failed boiler.

If your car worked the same or worse after the repair shop worked on it what would you do ???

Jamie Hall

To sort of answer one of your questions -- where is the water going-- in a very real way you know the answer, but it may not be obvious to you: it is going out into the various pipes and radiators and, eventually, it comes back. If you had a serious leak somewhere, like a problem with the boiler, it wouldn't be coming back. Now then the question becomes why isn't it coming back sooner? And the Scullys will get to that, but for the moment there are really two possibilities (and it's probably some of each). Some of the pipes in your system are below the water line, no doubt, and they are called wet returns. They bring the condensate from the radiators and all back to the boiler -- and over time they do tend to get somewhat gunked up and need to be flushed out (they are the only pipes that do -- the pipes above the boiler water level don't get gunked). When they do get gunked, the ater can't drain back to the boiler as fast as it should -- and so the water level in the boiler drops. The other part is that some of the pipes may not have the right pitch -- they must be slightly off level -- for the water to drain back freely, and that can also lead to the water evel dropping. Pitch problems are not uncommon in older houses -- and more common when various "renovations" have been done to the system over time without really thinking them through.

Plumbers often can't quite figure this out. The Scullys can, and will.

As for the radiator that isn't heating but is dripping from both ends -- again, it's a problem with the water not draining properly out of it. There are several possibilities here -- and one of them you can check after you read this: is the inlet valve fully open (all the way counterclockwise)?

WMno57

When water becomes steam it expands in volume 1700 times
When steam condenses to water it shrinks in volume 1700 times
If steam collides with water at places in the system where this was not intended, the volume changes cause loud knocking.
That is way venting and pitch are important.

dabrakeman

To get to the bottom of things you are also probably going to need to grant the Sully's access to parts of your system that may be hidden, like:
1) the end of the main to locate and evaluate the main vent situation
2) The full length of the main to verify proper pitch
3) the takeoff from the main to the spitting kitchen radiator to check its pitch.
4) any wet returns

This would have to be done new boiler or not. As a fellow homeowner I understand wanting to save money. If the boiler is not leaking then maybe you can avoid (for the short term) putting a whole new boiler and near boiler piping in particularly if your system worked adequately before. You can save yourself a little by by paying yourself to do some of the work to open these areas up rather than paying a professionals time to do it. I am sure if you asked Scully "what can I do to help the diagnosis process " he would be probably willing to work with you.

Anything else you can think of that might have changed from when things seemed to work to now? Any renovation work? New floors are carpets that might have changed radiator heights? Of course it is also possible that long term settling just recently put things over a tipping point when it comes to pitch.

A few more pictures would also be helpful since it is unclear to me at least where in your system some of your supply pipes go from the boiler and where and how things drop to returns.

montek

There is No way I can do any of this myself- I truly do have 2 left hands and I would NOT know where to begin. I am just going to TRUST Scullys to know what to do and do the best they can. That is the problem with owning a home. Things go south and the house can become a money pit, especially after so many years. The only plus we can say is that we have NOT put real money into this system since we moved in back in 1989. So I guess it may be time to do so. This will probably be the largest job in the house that we have done since we moved in. We did cosmetics here and there BUT nothing like this- so I guess we must pay the piper sooner or later. We plan to be here for another 20 years (I am 67) and if that is the case we may as well do it NOW while I and my wife are still working for the near future. Agreed?

montek

Jamie Hall

"And then in the future, we can always purchase a NEW boiler and all this OTHER stuff will already have been taken care of- does that sound like it is the right thing to do?"

Yup

109A_5

Hello @montek,
I would just repair what is causing the problem(s). Which is probably NOT the boiler or the copper pipe at the boiler since apparently it has worked fairly well for decades.

WMno57

Some here say "don't replace a boiler, unless it leaks". I'm usually in that group. Given your age, skill set, and some assumptions about the condition of your boiler, I recommend replace.
Some things to consider if you are thinking about keeping:
You have a gas atmospheric burner. These rot out. What kind of shape is yours?
How much make up water has your boiler taken on over the last 30 years?
Has your boiler ever been flushed or de-mudded?
Did you ever overfill your boiler at the end of the heating season and then run it up to temp? You should have, guessing you never did this.

dabrakeman

To answer one of your questions the boiler is 1985 manufacture based on the serial number (first two numbers are the week and second two are the year).

montek

I was given 3 options for the work to be done- maybe you can help me decide by looking them over- thank you Option1(good option)Summary

Remove/dispose existing low water cut off.
Supply/install new low water cut off.
Remove/dispose (8) existing radiator vents.
Supply/install (8) new radiator vents.
Vents to be sized based off cubic feet of air in radiators.
(1) Vent to be credited from 1/27/24 replacement.
Installation to include main vent, requiring access panel in sheetrock.
Installation to include "no return" flush.
All work to be tested.
SECOND option- (called Better Option)

Repipe boiler to allow for header, equalizer, skim station.
Skim boiler.
Remove/dispose existing low water cut off.
Supply/install new low water cut off.
Remove/dispose (8) existing radiator vents.
Supply/install (8) new radiator vents.
Vents to be sized based off cubic feet of air in radiators.
(1) Vent to be credited from 1/27/24 replacement.
stallation to include main vent, requiring access panel in sheetrock.
All work to be tested.
Third option-(best by plumber)

Remove/dispose existing boiler.
Existing water heater to remain.
Supply/install New Yorker gas fired steam boiler, model # CGS50.
Boiler sized according to connected radiation
Installation to include new drop header.
Installation to include boiler skimming/water testing.
Boiler to be manually fed.
Steam header pipe/fittings to be black iron/steel.
Installation to include (1) new appropriately sized main steam vent (requiring access panel in sheetrock) and (8) new appropriately sized radiator vents.
(1) Vent to be credited from 1/27/24 replacement.
Installation to include connection to existing condensate zone with use of 3 piece bronze circulator
Installation to include all boiler wiring. Boiler wiring to be defined as wiring of boiler controls.
Existing thermostats to remain.
Installation to include flue piping from boiler to chimney base/flue branch.
Installation to include chimney inspection.
Chimney lining not included, if required.
Installation to include (2) 12"x12" louvers in mechanical room to communicate with additional rooms for combustion air requirements.
GENERAL 1-PIPE STEAM SYSTEM RECOMMENDATIONS (NOT INCLUDED):
-Installation/inspection of pipe insulation. All steam main piping/radiator runout piping should be insulated, as it increases system efficiency and overall system performance. Additionally, any existing pipe insulation should be inspected for integrity.
-Radiator hand valve replacement. While they may not currently be leaking/inoperable, they have a life span and will eventually need to be replaced.

ADDITIONAL CONSIDERATION:
-Boiler replacement is gas to gas and should not require a whole house gas pressure test, the cost of which is not included, if required.
The prices are quite high for me but it is what is--- I am OK with all But again what do you suggest now that you see what will be done. Thank you all

neilc

let the Sculleys repipe that copper piped mess of a water pump steamer, and whatever else they see in that basement,
then come back and tell us how grateful you are

dabrakeman

@montek Please remove the pricing from your post (edit post). It is forum rules that contractor pricing is not allowed to be displayed.

I would do 1 or 3. Probably 3.

montek

??:(

montek

About your choice - why wouldn't I do Number 2? I thought that by doing number 2 I was getting as close to a good operating fix without a boiler change- and so if I needed the boiler afterward it would not be a huge job then. what are your explanations for picking number 1 and then number 3 and NOT number 2 especially knowing where the future might end me up at? Thank you

ethicalpaul

neilc said:

let the Sculleys repipe that copper piped mess of a water pump steamer, and whatever else they see in that basement,
then come back and tell us how grateful you are

A fair dollar for a fair service, I'm not sure grateful is part of the equation....it should be the norm

neilc

happy ?

dabrakeman

Was he going to verify and correct pipe pitch "if needed" in option 3?
If you decide to go with option 1 then I would maybe hold off on the 7 other radiator vents for now but maybe go ahead and replace the inlet valve on the problem radiator instead (he would be doing that in option 3 anyway). If you then know the main vent is good and the valve on the problem radiator is good but the radiator still doesn't heat and collects water then you know there is a pitch problem.

How much more would option 3 be if he did option 1 as I described first then if didn't work you both decided you needed to go to option 3 (don't give us the actual number )

montek

He already changed to vent on the problem radiator which now heats up somewhat but is leaking from that vent and I have towels down to absorb the water. He did say he was going to re-pitch the pipes if needed. On his first visit, he mentioned something about the pitch and the piping being wrong but like I said- it has functioned for over 30 years but he said that time has caught up with the system. From what number one says it seems that he will only be doing or changing the low water cut off which seems to be working OK except for the fact that the NEW water level in the sight glass is much lower than what it was normally. So not sure what changing that will do or why. He also mentioned something about not only changing the vents(he does not like the vari-vents) but also balancing the system. Whereas in number 2- he is repiping the boiler, header, and skim. Not sure what that is- but won't that be making the system ready for a new boiler in time? He also will be cutting through my sheetrock to check the Main Vent. So isn't this getting to the main crux of what my system needs? Number 2 is just about less than 2x the cost of number 1 and number 3 is about 2x more than number 2(but that includes a new boiler( is that a good brand?)

Jamie Hall

Well, they are ranked in order -- good, better, best. No argument there. All three options are quite reasonable and will work well. But I have no clue as to what your particularly financial circumstances are, nor what your future plans are. Only you have that information.

Therefore there is no way that I can tell you -- or even suggest to you -- which option you, personally, should take.