Last radiator will not get hot

kevindowling

I have a 1910 house, not sure when the steam pipes went in, but in 1987 the furnace was updated from a huge coal burner to a weil Mclain. For the past 3 years I have not been able to get the furthest radiator to get hot. It is on the first floor, and is about 60 feet from the boiler. I have one main line with two branches.The shorter branch all radiators work on both floors, this is about a forty foot branch. I replaced the main vents a few years ago which were plugged, and have a gorton main (1 or 2) on the short branch a hoffman 75 on the long branch. The radiator just before the one that does not works heats well, it is about 10-15 feet upstream of the radiator that does not heat.

Is there anything I could do about timing heat to radiators that could tell me whether ot not there is proper main vents installed?

In trouble shooting the last radiator a week ago, I disconnected it to from the valve, with the steam on and snaked it out, I breifly had a radiator which partially heated up for a few days but now it is back to no heat. Good this be due to insufficient venting at main (one hoffman 75). I am not sure how I got it to heat up for a few days, maybe there was a clog and it reclogged. I assume to check for a local clog , you could run the steam with an open valve and if steam comes out it is not clogged, if the steam does not come out a a fully open valve could something other than a clog be stopping it. Does anyone have any troubleshooting tips. Any books I could get to help.

nicholas bonham-carter

there are excellent books here in the shop- "The Lost Art of Steam Heating". Read it and you will know more than the majority of "plummmers" out there.
You need more main venting on this-one Gorton 2 for each 20 feet of main. If the pressure is above 1.5 psi, then that can slow down the steam.--NBC

BobC

Can you tell how close the steam gets to that last radiator? While trying to figure that out check the pipe and make sure it is consistently pitched back to the boiler. Your attempts at cleaning it out may have pushed some water back down the pipe and after running it a few days a new puddle of water appeared.

Bob

Fred

As NBC said, make sure you have plenty of venting on that main. One Hoffman 75 won't do. Also make sure you have a good vent on the radiator. It may not always open to let air out of that radiator.

Abracadabra

What is total attached EDR?
What is the sq.ft. steam rating of the boiler?

j a_2

N B C What would make you make a statement that if one is to read a book one will know more than most PLUMBERS….

SWEI

The sad fact is that in this day and age, the overwhelming majority of licensed HVAC and plumbing contractors know bupkus about steam. It gets worse as you move west.

j a_2

Shame on them, and shame on the home owner for not doing his homework…before hiring Handy Andy….They sure know how to do there homework when the banging,hissing and C O detectors go off…Friend of mines Mom, has not lived in her home of 85Plus because some knuckle head oil company totally screwed up an replacement boiler…Then they tied in a hybrid elect water heater to a tankless…Oh ya baby now the oils flowing...

j a_2

From many many of the pics I see here, they did hire Handy Andy…To a real plumber, piping the steam boiler is only a portion of what it takes to do a complete install…Take into the consideration, make up air, venting, sizing and the ability to service it…Also the ability to install it per local codes…In my state that requires a lic. plumber to do the complete job…With todays valuable internet a homeowner does have the ability to do his homework ,in a very short time…Here the code is not just a code its the law...

BeeDubya

Did Kevin ever resolve his problem? I must say I have exactly the same problem with a similar scenario. 1900's home with a master bedroom and bath added over a crawl space circa 1950 (judging by the bathroom style). I have good, well balanced heat everywhere else, upstairs, downstairs and INCLUDING the new bathroom off the master. But the bedroom radiator - only the first couple sections get luke warm. I have yet to check the pitch of the rad itself but the pipes under the house are hot and pitched about a half a bubble. I'm new to steam but absolutely love it and trying to learn what I can. I tried opening the vent all the way and could hear and feel air coming out but no heat or steam. The "new" runs are not insulated so there could be some early condensing going on there. That's a project for next summer but I'm wrestling with the idea of insulating the crawl space instead or also. There used to be a run to under the kitchen sink but that's been cut off and capped under the sink and also at the main. Sure would like to have that back cause the kitchen is stone cold.

Anyway, anything you can advise would be appreciated.

Bob

Fred

I'm going to assume the master bath is probably closer to the Main in the basement and the steam is not condensing in the radiator run because it is not as long of a run. (May be condensing some but still allowing enough steam to get to the radiator) Is that the case? The runs in the crawl space need to be insulated, even if you insulate the crawl space.
I'm also assumming you have a 1 pipe system since you say the radiators have vents on them. Correct?
Are both the Bath and Bedroom radiators connected to the same radiator run? What size pipe (s) are they?
What kind of vent do you have on the problem radiator? sometimes a little water in the radiator vent can block air from escaping., especially if it is venting fast. Take the vent off and shake it out and put it back on and see if the radiator heats up on the next cycle.
As far as the kitchen, if it had a radiator and there is a place to connect it on the main, assumming you have the boiler capacity, it should be pretty simple to put it back. Was it disconnected to provide the needed capacity to supply the new bath and bedroom? What is the total EDR of your radiators in the house and the sq. ft. steam rating of the boiler?

BeeDubya

Wow Fred. That was fast. Thanks for the quick reply. I don't know most of the answers to your questions - yet. I've just finished chapter 2 of Greening Steam because its a free preview to the only eBook I could find by Dan Holohan. I'll have to order a hard copy of "The Lost Art" I suppose. It's 2900 sq ft home and I am anxious to calculate and apply the 2-20-200 rule

I don't know much about how the piping should have been done for the addition but I have to say I don't like how it looks. The concrete block was chiseled out to the crawl space and there are two 12 inch risers leading to two parallel 2" pipe runs. The rad in the master is 6 feet away from the one in the bath so the length of the run to each has got to be close to the same length but I'll have to double check.

There is a large missile shaped valve on one end of the main that appears to function as it should - lets air out a hellun but no steam or spitting comes out. I wondered why there isn't one at the other end where the new risers and parallel runs are attached.

Most of the radiators have chrome valves with numbers on and I learned the farther from the boiler should have a higher number. It took me a while to figure out the round part with the numbers on just spins and spins and doesn't do anything but it's the nut on top that adjusts the flow of air.

And on a 1 pipe system I learned the rads should either be on fully or off fully and I thought some people may like it cooler in the bedroom and may have turned the valve off or down. So after wrestling the valve without a knob I got it loose and found it was all the way open anyway.

I have a PV85ST-HBUR Burnham boiler that says 512 sq ft of steam and that it is 10 years old. It could be that the kitchen was exchanged for the addition and would make sense as a one for one swap for the bath and leaving the master starved but I will never know the real reason for cutting off the kitchen.
I can measure the pipe runs but how do I get the EDR of all my radiators (besides dipping them in paint and painting the floor etc, etc.)?

Thanks Fred.

BobC

If that main steam vent is doing it's job at a furious rate it tells us two things. First the pressure might be too high, what is the pressuretrol set to (both on the face and the white wheel behind the cover) and what does the pressure gauge say?

Second is you may need a lot more venting on the mains, silver bullet vents are low capacity vents you may nedd one or more Gorton #2's on the mains (Gorton #2 = ten of the silver bullets). How long is each main and what size pipe are they?

Bob

Fred

It does sound like you may need some additional vents on the Mains. The 'Rocket" looking thing at the end is maybe a Hoffman 75 Vent. Is it Green or copper colored? If so, they are good vents but 1 is not enough for an entire Main unless it is very, very short. You can't have too much venting on the Mains.
As BobC says, make sure your boiler pressure is where it should be. The Pressuretrol (the grey box mounted on a brass pigtail) on your boiler has a scale on the front of it. That dial should be set at .5PSI (all the way at the bottom of the scale) Adjust it using the screw on the top of the box. There is a screw on the bottom, front of the box. Loosen that and take the cover off. You will see a white wheel on the floor of that box, turn it to "1". That will give you a Cut-In of .5PSI and a Differential of 1PSI for a Cut-out of 1.5PSI. You should take the Pressuretrol off of the Pigtail and make sure that Pigtail is not clogged. It should be cleaned out at least once a year. If it is clogged, the Pressuretrol can't do it's job.
The silver vents on the radiators are Hoffman 1A vents. The part that spins does do something. It has an offset cutout under that screw top. By turning the cap to a specific number, the offset allows more of the vent hole to be exposed, hense more air to vent faster from the radiator. The screw on top simply holds that cap in place where you want it set. They are good vents and work well as long as you hold the cap on the venting number you want while your turn the screw top finger tight.

As for the Bedroom and bathroom radiators, Those pipes are radiator runs off of the Main. Typically they will not have vents on those lines as that air is vented through the radiator vents as the steam pushes through those pipes. You really need to make sure that bedroom vent is working properly and that the pipe run to that radiator is sloped back towards the Main that it is attached to. Insulate those pipes in that crawl space.
Test that radiator by taking the vent completly off off the radiator and turn the thermostat up so the boiler kicks on. see if steam starts to come out of the hole where the vent should be. If it does, that vent is probably bad. Be sure not to put your hand in front of the steam or it will burn you quickly. When the steam arrives, turn the thermostat down immediately to shut the boiler down or it will get very humid, very quickly in that bedroom. Put the vent (or a new one) back on.
Now, the radiator EDR. I have no clue what you mean when you say: "I can measure the pipe runs but how do I get the EDR of all my radiators (besides dipping them in paint and painting the floor etc, etc.)?"
Get Dan's book on Radiator EDR and it will give you the square feet of EDR for each type of radiator. The EDR is driven by the size (height, width, length) and type of radiator. You know your boiler is 512 sq.ft. The total of all your radiators should be very close to that number if the boiler was properly sized when it was installed. If it is too small, you may have issues adding additional radiators for the kitchen (maybe). If it is too large, that can cause pressure and short cycling issues and adding additional radiators will help alliviate some of those issues.

BeeDubya

Thanks guys. Here's what I'm going to try: check the pitch of the rad itself; double check the slope of the run; take the vent off and check that it's not clogged and leave it off just to see if steam gets through to it. Then I'll shut off the working rad in the bath and see if that makes a difference which might indicate a capacity problem.

The vent on the main is green not copper and not silver.

I'll check the pressuretrol settings and make sure it's set to .5 and 1. I can't quite make out the settings from the picture and I won't be back to the house till some time after the holidays.

Thanks for the replies guys.

Bob W

BeeDubya

You've probably seen 100's of these but here's a picture I took of the boiler. Another thought I'm having is converting to NG.

Fred

That green vent is a Hoffman 75.

BeeDubya

Thanks Fred. Too small for 512 sq ft or steam or can't tell until the total EDR is calculated?

Fred

You should have the equalivent of 1 Gorton #2 (2 Hofman 75's) for every 20 feet of 2 inch Main Piping, regardless of the Boiler Sq. Ft. rating.

Captain Who

@BeeDubya - I see from the picture you posted that your pigtail isn't oriented correctly relative to your pressuretrol. That's a mercury switch pressuretrol so it is important to level it and also for the pigtail to be at a right angle relative to the pressuretroll. When the pigtail heats up it will expand and contract which will tip the pressuretroll right and left (the way you have it), and that will also tend to tip the mercury switch, which is no good.

BeeDubya

Oh, that's right. Thanks Fred. It's 30 ft - so now I'm wondering if there used to be another Hofman at the other end before the expansion was added for the addition. And I'll have to double-check - there's piping that goes around to feed the radiators in the front of the house and I don't know if that's another main or part of the one.

Thanks for the observation @Captain. So if I loosen the fittings, keep the pressuretrol stationary and rotate the pigtail 90 degrees one way or the other and then make sure it is level (by rotating the whole assembly left or right) that would be the correction?

Lots to discover - lots to learn...

Captain Who

@BeeDubya - Yep sounds like ya got it. Hopefully everything is a little loose right now and not super tight. That way you can turn the pigtail + pressuretroll assy 90deg clockwise (with wires disconnected is best), and then turn the pressuretroll 270 deg clockwise and reattach the wires. If things are already too tight then you'll have to do it differently. Always use a parallel jaw crescent wrench on the pressuretroll. Don't ever turn it with your hands and don't overtighten it.

Fred

Yep, That's a Mercury switch on that Presssuretrol so you want to turn that pigtail so that it is at 90 degrees to the Pressuretrol (they expand contract when they heat/cool. Forwrd/backward mothion is OK but side to sid motion affects the switch. Once you do that, put a level on the top of the Pressuretrol and make sure it is level from side to side.

BeeDubya

Thanks guys. I think as long as I can loosen and tighten the fittings without having to apply too much pressure (groan - sorry, had to do it) I should be ok.