high pressure after removing radiator.

bmedeiros678

Hi All. I have found this forum very useful. I have searched for an answer to my latest question but havent been able to find the answer. Hoping you can steer me in the right direction. Last week I removed a raditor from my one pipe steam system and capped off the pipe. Now a few days later I woke up to what sounded like a whale breaching in the basement. I take a look and there is steam everywhere. It was coming from the pressure relief valve and the pressure gauge was reading 15 psi. I just moved into the home two months ago. Had the boiler serviced last month. I know the boiler is 10 years old and hadn't been cleaned in 4 years. My question is did removing the radiator make more pressure in the boiler or is that a coincidence?

KC_Jones

If you have steam coming from the pressure relief you either have a bad pressure relief or one of your safeties has failed in some way. The pressuretrol is there to prevent the boiler from going above a certain level generally 1.5-2 PSI max. I suggest you get your service company back pronto to find out what the problem is. Above all else I would shut that boiler down immediately! You have a potentially serious safety issue going on right now and need to get it addressed. A few suggestions as to what could be causing this.
1. bad pressuretrol
2. clogged pigtail on the pressuretrol (this should have been checked when the unit was serviced). If it's clogged completely the pressuretrol can't "see" the actual pressure and won't accuate
3. bad pressure relief valve
4. Incorrect setting on pressuretrol...this is highly unlikely, but could be part of the issue if the pressure relief is "weak".
5. removing a radiator will never cause this to happen.

No matter what I would have that pressure relief replaced when you get this under control. Now that it has been operated it's just a good practice to replace it. Safety is nothing to mess with.

Abracadabra

What is the pressuretrol set at? It shouldn't be set to anything over 1-1.5PSI. If it's over, lower it. Ensure the gauge reading correctly? You may need to replace the gauge. If the pressuretrol is on a seperate pigtail from the gauge, check and clear the pigtail to the pressuretrol if needed.

bmedeiros678

Thanks for the quick responses. I know that the pressuretrol is set to "normal" something like 1-2 psi. I'm not home so I can't look at it right now. I also know that the pigtail was not checked during service. The unit is shut down for heat but still heating my water. What does a technician do to clean the pigtail? Does he just use a pipe-cleaner or is it more complicated then that?

KC_Jones

Depends how cruddy it is. If that IS the cause it is probably pretty well clogged and may just need replaced, hard to say without seeing it. If they can clean it, it will need to have all the crud blown out/pushed out. Even running clean water through it. It should be completely removed from the boiler for this service, you don't want that crud to get pushed into your boiler. This should be part of ANY yearly maintenance done to a steam boiler. Did they check your low water cut off? If it's a probe type they should have pulled that out and cleaned it then verified it's operation. I am assuming this is an oil boiler. Did they clean the combustion chamber out? Did they tune and perform a complete combustion analysis AND give you a print out of all the combustion numbers?

Fred

Running at pressures that high could affect your Main vents as well as the radiator vents. Once you get the boiler under control, if you find that some of the radiators won't heat, it probably because the radiators vents are stuck closed. You can try to tap them and see if they open and work properly after that. If not, they may need to be replaced. Same goes for the vents on the Mains. If it seems that it takes a lot longer for steam to fill the Mains, check to see if the Main Vents are stuck closed.
As a new homeowner and new to Steam heat, you would be well served to familarize yourself with the Boiler (the system in general) and either take responsibility for the maintenance or giving the service company a list of things they must do, as part of the annual maintenance and watching the maintenance people to make sure they do it.

bmedeiros678

Thank you Fred. I replaced the vents on the radiators a few weeks ago. One of the rooms was not heating up so I figured the vent was the problem. It was. The other thing my wife said I needed to mention was after the radiator was removed the pipe was shut off but leaked when the heat was on. The contractor had Blueboard resting on that wall so we couldn't access the vent to cap it off. We just kept filling the boiler with water daily after having the heat off most of the day. Maybe by having the water get low I made some gunk get loose and clog the pigtail. Either that or more serious damage was done. Could be an expensive lesson.

Fred

You never want to add fresh water to your boiler on a regular basis, certainly not daily. That much fresh water will cause the boiler to rot out well before it should (It will take years off of the life of a boiler). The pigtail should be above the water line on the boiler. If it is, it probably was not exposed to any additional gunk, although some may have washed back into the boiler and the boiler may need to be drained and flushed out. After you flush it, Turn the thermostat up and let thee boiler run for 15 to 30 minutes to burn off any excess oxygen in the fresh water (which is the cause of early rust-through).
If you have a Float type Low water cut-off, like the McDonnell and Miller, and the pigtail is mounted on top of that, it certainly is subject to gunk and clogging up fairly easily.
In any case, you need to take the steps others have suggested and make sure the Pressuretrol is working, the pigtail is clean and open, the Pressure Relief valve is replaced and that your Low Water Cut-off is working so that you don't run the boiler dry which can be dangerous. Steam heat is a fantasticc heating system but like any other system, it has to be respected and maintained.

Steamhead

Why did you remove the radiator?

bmedeiros678

To install a wood stove. I replaced the clogged pigtail and now the boiler is shutting off when the psi is reaching 3 psi. I read about main vents. Is my system supposed to have one?

Abracadabra

bmedeiros678 said:

To install a wood stove. I replaced the clogged pigtail and now the boiler is shutting off when the psi is reaching 3 psi. I read about main vents. Is my system supposed to have one?

3 psi is still too high.
Yes you need main vents.
I assume this is 1-pipe steam?

KC_Jones

There should be main vents at the end of all mains. Post the size and length of your mains and we can recommend how much main venting you require. And again 3PSI is too high. You should turn the pressuretrol down as low as you can get it.

bmedeiros678

I agree. Still too high. It is a one pipe steam system. I will take pictures of my system but for the life of me I can't find a main vent. The old pigtail was completely blocked. I also cleared out the tiny hole inside the fitting of the pressuretrol. Looks like I have an old mercury filled one. Trying to get it as close to level as possible. Also when the system shuts down the radiators seem like they are sucking in air like crazy. Like its grasping for air.

KC_Jones

That is because of the higher pressure, when all that steam collapses it creates a vacuum that sucks in air. It has been said any noise coming from a steam system is a cry for help. Main venting and lowering the pressure will help with this. Main venting will keep the pressure down as well. If your system is well matched you may never cut out with the pressuretrol, but given your recent issue I doubt that is the case.

bmedeiros678

If I am correct the pressuretrol shuts down the boiler when the pressure gets too high? and the system will create its own pressure if there is no control to make it shut off? The system was running for a few minutes and then would shut off for a few minutes. Then turn back on. Could the boiler now be too big for the remaining radiators? It's only an 800 sf house but the boiler looks huge. Also the pipe where I removed the radiator and capped it off is a "long" run leading to nowhere. Is it bad to leave an empty pipe attached to the system?

bmedeiros678

Thank you KC! I am starting to understand how well balanced the system needs to be.

KC_Jones

Sounds like your boiler may be over sized and your main venting is inadequate. You are short cycling. The long pipe isn't an issue, but removing that rad has amplified the problem. I wouldn't have removed it even with adding a woodstove. You would have been better off just putting a really slow vent on that radiator. You need to get some good main venting and that may help, also get the pressuretrol turned down...the extra pressure isn't doing anything for you. I would consider putting that radiator back if I was you.

bmedeiros678

What if I install it in another room? Would that balance it out again?

Charlie from wmass

The money for the wood stove may have gone farther being applied to a new properly sized boiler. Installing a radiator in a room you do not need it is like applying the emergency brake to slow your speed instead of letting off the accelerator.

KC_Jones

It would probably be a good idea to do a full EDR calculation for your radiators then compare that to the boiler size and see where you are at. Calculate with and without the removed radiator. This will go a long way to developing a course of action going forward. Also as stated before measure the size and length of your mains as well for the venting. I agree with Charlie what's done is done on the removal of the rad. Just out of curiosity why did you decide to install a wood stove and remove that radiator?

bmedeiros678

I can answer that. The room is a little more than 8 x8. That connects to another room. The new stove came with the house so I didn't pay for it. I have 4 acres of woods so I figured why not make use of the wood stove. This is temporary though because the wall that is behind the stove/radiator is being taken down for an addition. Sooner or later this issue would have come up. The radiator is in the attached pic. This photo was taken before we purchased.

Marz

Is this an oil boiler? If it is chances are it is oversized, but 100 to 1 shot that it is way overfired. Lowering the firing rate will certainly help the short cycling. Sounds like it's getting to pressure way to fast. I would fix the main venting as well.

bmedeiros678

It is oil. I will post pipe sizes and lengths. I am really learning a lot. Thank you all. Is this pressure issue affecting my "tankless" water as well?