Pressuretrol settings. Cut in @ 3 lbs. Diff @ 2 lbs. Thoughts ?
Comments
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When you are baking bread. or brewing beer
Do you see yourself doing that any time in the future
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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My cut in = 3 and diff = 2
Should I try setting cut in = 1 and diff = 1 ?
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Let's try this again. Assuming you are using the pressure control in the photographs, that is an ADDITIVE pressure control. Thus, as it says on the label, one scale (the left) sets the cutin point. The scale on the right sets the differential, and adding the differential to the cutin gives you the coutout.
As I said earlier, such a pressure control device should have a cutin significantly greater than 0, and 1 psi is a good number. I wouldn't set that one at less than that, as it is old and may not be completely in calibration. Similarly the differential should not be set too small, and 1 is a reasonably compromise. This will give a cutout of 2 psig, more or less, which is a bit high about the best you can do with that unit.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
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Did not want to make huge changes at once, so I adjusted the cut in from 3 down to 2. Did not touch the diff=2. If this cut in=2 makes the boiler not work anymore, I will put it back to 3. It was lefty-loosey to make the slider go down. The slider barely moves when you turn the screw, so it took like 20 turns of the screw.
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I ran the heat with cut-in=2 & diff=2
House is 63F at 0:00
Slide T'stat to 64. Boiler starts
Boiler ran for 30 mins and turned off when room temp hit 65F
Boiler did not short cycle.
But, maybe that's since boiler only had to raise temps a few degrees.Since it appeared to run ok at cut-in=2,
I just dropped the cut-in to 1.5 for next time.
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So you are allowing your pressure to rise as high as 4psi before cutting out and restarting as soon as it gets back down to 2psi. Don't think your vents are going to be happy long term with this if you indeed are reaching those pressures. Curious why you would not try the suggestion of 1 and 1? With all the separate strings I can't remember if you have a low pressure gage to see true pressure?
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The logic is:
- Someone set it to 3 & 2 for a reason. No idea what that reason is, however.
- Boiler is likely oversized (100-150k BTU vs. 52k EDR calc)
- System currently seems to work, and I don't want to break it. It has been set like this for decades, probably.
- No idea if pressuretrol even works, as it's probably not been cleaned out for decades, if ever. (80 years old, no pigtail)
In this thread, I learned / we established there is no upside to allowing high pressure. Better off short cycling than to keep burning fuel when rads are full.
So, I thought I would make gradual adjustments.
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That logic has a flaw;
The 3 & 2 may have been where the pressure switch manufacture set it at and also tested it at those pressures. It has been presented here on HH before that the boiler installer just left the Pressuretrol (the more modern equivalent of your pressure switch) where the pressure switch factory had it.
It is adjustable to accommodate different systems and their needs, small residential steam systems usually benefit with these pressure switches set to the minimum setting where they still remain functional.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System2 -
@CoachBoilermaker Sent you a PM.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
@CoachBoilermaker I'm just a homeowner enthusiast, so take my comments with a grain of salt….but I see a number of safety red flags here.
- Your 0-30psi gauge is broken. These are required by code just in case the boiler is running way over pressure. How do you know what your operating pressure is actually at?
- Maybe the Pressuretrol is not even functioning? Perhaps you are operating at 10psi? Who knows?
- Furthermore, those 0-30psi gauges are not accurate at all at the low end of the scale where we actually operate. Add a 0-3psi gauge so you know what is actually going on.
- When was the last time the boiler was serviced? The pigtail cleaned? The LWCO cleaned, inspected and tested? Do you test the pressure relief valve often?
Your boiler was installed when D-Day was occurring… when was the last time a steam expert serviced the boiler and all its safety controls?
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I'll bet the only test a patch of Ptrols ever srr is to ,ake sure they cut out at 15 PSI, they don't care what it does anyplace else
Bob
Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
Vaporstat with a 12oz cut-out and 4oz cut-in
3PSI gauge1 -
- I have no idea what operating pressure is at.
- Agreed. Pressuretrol very well may not be working. May have clogged decades ago
- I had a thread about replacing the gauge and someone suggested adding a 0-3 PSI gauge, but it was too complicated for me Didn't know how to order parts, or how to fork the existing pipe. Went nowhere.
- Boiler gets new nozzle, filter, strainer from local oil company. Pretty sure that's it. Last service was a disaster as the tech had no idea about anything beyond those 3. He refused to test the pressure relief and did not understand what the LWCO switch was. There is no pigtail, just a straight pipe. I doubt it has been cleaned in decades.
I'm not even sure the heat exchanger soot has ever been cleaned. No one can figure out where the access panel is. Regarding boiler clean out, what's your best guess where the cleaning access for wire brushing the exchanger nipples/grates would be?
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@CoachBoilermaker I'd highly recommend finding a steam pro, preferably from here to take a look. Not to be an alarmist but this sounds like a ticking time bomb (potentially literally).
All of your safety control devices are of unknown condition and may or may not be working. I'd try to find someone to make sure it is operating safely ASAP.
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I never knew how little pressure was in my boiler until I added a 0-5 inches of water magnahelic. I didn’t understand that I needed the negative part of the scale … when the burner turns off and the system goes into vacuum.
setting my new “zero” at 2.5 inches on the scale and it never hits 1 or 4
if coach boilermaker questions the need for his pressuretrol settings, just add a pressure gauge with a scale in the meaningful range and see that the pressure never gets anywhere near that.0 -
The last post in your "gage" thread clearly shows how to remove the old gage. I don't think it was going nowhere. If you have no confidence to do any of the procedures being recommended to you then you have no choice but to find a qualified pro. I think you have to do this anyway. With all the different threads you have going I'm not even sure where you are located. In the meantime you could work from a priority list and focus on one thing at a time. Get from the group straightforward directions on how to accomplish each task one at a time. My suggestion would be:
- Find contractor from group here based on your location. Also get and read We got Steam (book avilable from store on this site)
- Safety devices first - LWCO functionality test. Knowing whether your pressuretrol is working is going to require step 2 which is a functional gage
- Add new working 30psi and 3psi gages after making sure outlet pipe to existing gage is clear. A pigtail should be added to protect the new gages.
- Set pressuretrol at 1 and 1.
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In your thread "Went Nowhere" you actually received a great response from @PEvans with this picture
I am sure that you have a pressure relief valve on your boiler somewhere. Do you follow the instructions that are on the tag that comes with every pressure relief valve? Do you operate at least once a year? ("Operate a relief valve means" to open the manual lever when there is pressure in the boiler to see of steam comes out to make sure the passages are clear)
Many folks don't do this. Even professionals don't do it for you, and I can't understand why. If the valve is defective, then you need to replace it. And replacing parts is one of the best ways for HVAC and plumbing companies to make money. So finding a defective relief valve seems to be a no brainer to me! Just make sure you have the right replacement valve before you operate the existing valve. Can't make money on a part if you don't have it to sell.
Back to the photo: you can purchase a few 3/4" fittings and remove the relief valve, install a Tee fitting, then place the relief valve back or the other end of the tee fitting. On the branch of the tee you can build the pigtail, and new gauge and new pressure control that will be in addition to the parts you already have that you are not sure are operating properly. Leave the original parts in place, and just connect the new ones at the relief valve location. This is a no brainer.
As far a removing soot from the heat exchanger, there are 4 ways into your boiler's heat exchanger.
- Remove the flue connector. (the smoke pipe between the boiler and the chimney)
- The access on the right side where the wall has a hatch for access. That large panel has a fastener hole that appears to have a missing fastener. Look for other similar holes or fasteners and remove as needed, then lift the panel and pull the bottom out. then let the panel drop to the floor below the blocks. Slide the panel to the left for access to the cast iron that will have a door or series of doors to access the heat exchanger.
- The rear opening looks to be about a 7" to 9" diameter door that may be removable, but you may not need to remove it, if you look thru the smaller peep hole when the burner is operating you can see the condition of the combustion chamber and see if there is excessive debris in the chamber or if the chamber needs replacing.
- the front burner door is removable to replace the chamber by removing the large nuts. That can be done with the burner attached or with the burner removed. To remove the burner,without disconnecting the fuel lines and making a mess just remove the fuel pump from the burner and let it hang on the fuel lines while you remove the big door. You only need to remove that door if you need to replace the chamber. You can vacuum the chamber from the rear door for annual vacuuming.
Flue connector not shown
Right side when looking at the oil burner
Rear access to the combustion chamber that you can put your arm and vacuum hose thru
Front combustion chamber access.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Think of it this way. The boiler puts out steam. The radiators condense steam and give off heat. The capacity of the radiators is fixed.
If you put more steam into the system than the rads will condense the pressure will rise. If you put the same amount of steam into the system than the rads will condense you're in perfect balance.
If you put less steam into the system than the radiator capacity you risk not being able to heat all the radiation.
The radiation controls the system pressure.
The boiler input and thus the steam output weather gas or oil can be adjusted slightly lower than the maximum allowed in most cases.
If the pressure control never trips because the system pressure never raises who cares where it is set at as long as it is below 15 psi.
The only time the pressure control setting come into play is if the boiler is oversized for the system.
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thanks 109a5,
Unfortunately the first one was $70 and I’m not sending it back after I already installed it.
I should have bought the one you pictured … live and learn0 -
I had someone from this forum take a look. He said he would refuse to service it because of liability. He gave me a quote for a new system. There is no one else on this forum within a 90 minute radius of my area.
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That is why some folks learn what they need to learn and they DIY. Whether you are a Pro or a DIY there is some satisfaction in a job well done.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
I tested the heat again today.
Recall, this time, the cut-in=1.5 and diff=2
LR is 62F
Set thermostat to 650:00 - LR temp is 62
10:00 - LR temp is 62
20:00 - LR temp is 62
30:00 - LR temp is 64 (All radiator sections mostly all full)
36:00 - LR temp is 65
43:00 - LR temp is 66 (Boiler shuts off)After about 30 mins., all the rads were basically full. All sections hot.
Boiler kept running until 43:00 when thermostat was satisfied at 65.
To review the big idea behind short cycling, is 30 mins. where an even lower pressuretrol of cut-in=1 should/would cut off the boiler once rads are full, and making more steam is pointless? Is the ideal short cycle to cut off the boiler at 30 mins., once rads are full? The vents did start hissing a bit once last rad sections were hot, but they all stopped hissing after a few more mins.
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Cycling has nothing to do with specific times. It has to do with pressure. If the pressure was holding (you don't way where you have the cutout pressure set currently) then things were working as they should. If it was rising much above a pound and a half to two pounds, then it wasn't — and you should reduce the cutout pressure.
But you can only judge that if you have a reliable low pressure gauge on the system!
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Hello CoachBoilermaker,
You wrote earlier in this thread:
" To recap, oversized boiler will create excess steam and raise pressure.
I guess it comes down to 3 choices:
- Replace boiler for $20k
- Short cycle boiler at 1 lb. (longer to heat up)
- Raise pressure to 3 lbs.
How does allowing system to operate under higher pressure waste fuel compared to short cycling?
For the millions of homes running an oversized boiler, which lesser evil is preferred, short cycling or high pressure? "
There is a 4th option that I posted that you seemed to have ignored. Set the pressure switch to the minimum so you are not wasting fuel building pressure (if you actually do) and install an inexpensive timer to eliminate the short cycling. So no significant pressure and no short cycling, no lesser of two evils, run the boiler until it fails, it may out live us all with a bit of TLC.
Also I would say your 2nd option is not accurate, If you are building pressure the radiators are mostly full and are not getting much hotter, so not "longer to heat up".
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
Your 4th option. Timer sounds like it just simulates short cycle. What's the advantage? Timer will cut out sooner? No need for wasted fuel to build pressure to trigger cut off via pressuretrol?
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The timer I specified earlier (Delay on Break) is triggered when the circuit is interrupted, the interruption is the pressure switch (Pressuretrol) tripping, then the delay starts. So it extends the burner off time that the pressure would normally use to dissipate down.
If you are tripping on pressure there is no reason for the boiler to come back on the instant the pressure drops enough to satisfy the pressure switch's differential.
Example; If the system shuts down on pressure instead of a short delay for the pressure to drop and then just restarting the burner again (short cycling) the additional delay (off time) provided by the timer prevents the restart for an additional fixed period of time. During this fixed period of time the hot radiators may satisfy the thermostat. Meanwhile if the thermostat was satisfied the timer's timeout period will expire and be ready for the next normal call for heat. So if it is set correctly it won't modify the heating systems natural duty cycle with varying loads due to the outdoor temperature change.
The timer is adjustable from .3 Minutes to 10 Minutes. Example; So 4 Minutes may work good for some systems, 8 Minutes may work better for others.
" Timer sounds like it just simulates short cycle ". No it extends the 'Off' part of what was the 'short cycle' time period, which basically eliminates the short cycle phenomenon. A 'short cycle' is a needless System Off then System On cycling in useless short period of time. Extending the Off time eliminates the On time of a short cycle.
The advantage is no short cycling, which is needless wear and tear on the equipment.
The timer works in concert with the pressuretrol functionality not instead of.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System1 -
Here is example of another way to break up the recovery via thermostat control (Ecobee). My oversized boiler will start building pressure with filled radiators in as little as 30minutes when system warm so I avoid letting the boiler run more than 30 minutes at a time on recovery. 30min on, 30 min off and rooms continue to heat while the boiler is off for most of those 30 minutes unless it is bitterly cold out. 109A's solution is a bit more elegant but both work.
About once a year I will do a smaller manual recovery letting it go all at once just to make sure the pressuretrol and radiator vents are still working properly. Then it sounds like a 19th century steam factory with all the Hoffman vents clicking on and off…
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What I meant was at 30:00, all my radiator sections are now hot. Yet, thermostat is not yet satisfied. This is when you'd want the boiler to stop, correct? Instead, my boiler keeps running until 43:00, when the thermostat is ostensibly satisfied. If the pressuretrol was set at 1&1, it may stop the boiler when all rads are full, and there is no benefit to creating more steam, correct?
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It is my belief that it doesn't make sense to keep burning fuel when the radiators are full of steam if pressure continues to build (which most system will do)
If a system is correctly sized so that it is condensing all the steam that the boiler is creating, then maybe it is better to let it keep running.
But even in that case I am not opposed to cutting the burners for awhile to reduce or eliminate overshoot.
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el0 -
It all depends somewhat on the system and the conditions the system is encountering.
Let us, for the moment, take Cedric as our example — since @ethicalpaul takes his own system.
First, consider the way Cedric runs regardless of outside considerations — thermostat cranked way up and cool, if not cold, spaces.
Cedric fires, and takes around 5 minutes to build steam. At that point the pressure in the system rises to around 3 ounces or so — and stabilises at that level. Steam is fed to the radiation, which begins to condense the steam; all radiators are hot, but not yet at full power output, in about 15 minutes total. For the next half hour — total 45 minutes from steam — the radiation comes up to full power. At that point, but not until, the pressure starts to rise again. Now is where it gets interesting. The vapourstat shuts off the burner, and the pressure immediately starts to fall while the burner goes through it's post-purge, which is 30 seconds. By then, the vapourstat will have cut back in, and the burner starts its pre-purge and after that the boiler fires again. The cycle after that will be about 10 minutes to 15 minutes on while the radiation comes back up to full power and 1 minute off and would continue until we all cooked.
Because the boiler is closely matched to the radiation, and the radiation is closely matched to the heat load of the building on some days (granted, no more than a week or two in the winter), if Cedric were arbitrarily held off after a shut down on pressure, the system would not be able to match the heat loss of the building.
Now depending on the nature of the load to power mismatch, it may be advantageous to hold the burner off, but only if the mismatch is between the radiation and the radiation, with the actual heat load being significantly less than the available power from the radiation. A properly adjusted thermostat should be doing this hold off, however — not an arbitrary timer.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
One key to remember is that some folks have a vaporstat while many do not. Cycling on pressure may be tolerable when controlled to less than a half a psi but not so much when a pressuretrol often can't get any lower than 2psi.
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Oh quite. Every system is different — that's what makes it all fun!
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Last setting was 1.5 & 1.5. Now, I bit the bullet and adjusted it to 1 & 1. This is to hopefully counter the minor issue of hissing vents once the rads are full and boiler is still running.
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you have 2 threads open(?)
known to beat dead horses0 -
I swear I saw this picture in the other thread, and answered there, then did a strikethru/delete, I forgot to answer here,
known to beat dead horses0 -
I really do know what I'm trying to do, just have fat fingers, you should see me on a cell phone, butt dialing all day
so, right now, on that Ptrol picture, 1 + 1, your cutting out at 2,
I would turn the left, Cut In, scale down further, to 0.5, or as low as it can go and still restart the burner,(you can always dial it back up), don't force the adjustment or you'll disconnect inside.
watch a cycle on your gage and see if you're cutting out at 2, or higher? those scales aren't their most accurate,
is your pigtail clear? including all the way back into the boiler?
what pressure do you see on the gage when the boiler is firing?
known to beat dead horses0 -
@CoachBoilermaker, can you please wrap up your other threads before opening any more new ones? It's causing confusion. Thanks!
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