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Jamie Hall

Jamie Hall

Joined on September 16, 2002

Last Post on April 24, 2014

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Water hammer

@ April 3, 2014 9:26 AM in Copper Joint that leaks in main pipe Solution please

can generate overpressures quite sufficient to actually break pipe -- never mind joints.  I quite agree that the best way to handle this one is to change that copper out and put in iron.

But you say you can't do anything about the water hammer.  Why not?  Water hammer isn't an inevitable part of any plumbing system -- whether it's residential or 60 inch municipal mains.  Don't give up on that -- you control the system, you should spend some time to figure out where the water hammer is coming from and fix it.

Quite true

@ April 1, 2014 9:21 PM in Thermal Expansion Tank

a pressure reducing valve or a backflow preventer or a check valve -- anything that prevents flow back from the system.

As Steamhead said

@ April 1, 2014 8:37 PM in Value of converting oil/steam to modcon gas?

but with a bit more.  You may, very likely depending on prices, save some money converting the existing boiler, if it is fairly recent, to gas.  If it is an older boiler, you will also save some money installing a new gas fired boiler.  What you will NOT do is save anything by taking all the steam out and going to hydronic or hydro-aire; in fact, it is unlikely that you would ever be able to save enough on the slightly higher efficiency of a mod-con to pay for the conversion, even if you are adding ducted air conditioning.

Just the way it is.

Good thinking...

@ April 1, 2014 5:48 PM in Thermal Expansion Tank

but not quite!  First, you don't need an expansion tank on domestic hot water because the system isn't closed -- that is, the hot water tank is connected to the water supply at all times, so if expansion does occur (and it does) the pressure doesn't increase.  In principle, a very small amount of water is forced back out of the hot water tank into the rest of the domestic water supply system.

You do need one on a hydronic heating system, though, because the system is closed -- even if it is connected to your water supply, as most are, the connection is through a pressure reducing valve and a backflow preventer, so when expansion occurs there is nowhere for the water to go, and the pressure rises instead.

I'm not sure what a consensus would be on backflow preventers on steam boilers.  Certainly on power boilers and many process boilers, you would need a backflow preventer (if they were left connected at all; power boilers usually aren't) as the pressure inside is high.  But for residential boilers, the pressure is very low -- never more than 2 psi -- so unless the domestic water line dropped essentially to a vacuum you couldn't get backflow anyway.  That said, some authorities do require a backflow preventer.  It varies.  It won't hurt anything, anyway, on the boiler.

If you do indeed have a backflow preventer on your main domestic water line, then yes you would need an expansion tank for the hot water. 


@ April 1, 2014 3:03 PM in Thermal Expansion Tank

steam heat certainly does not need a thermal expansion tank!  That's hydronic only.  Nor does it need a backflow preventer on the feed lines -- in general.  I can see some overzealous building inspector possibly requiring though, come to think of it.

What are you using the 50 gallon hot water tank for?

And just to add

@ March 31, 2014 5:18 PM in Dormant commercial water heating system

to Ice and heatpro's comments (both excellent, naturally!) you also want that chlorinated water to be in there for a while and circulate -- circulation is very important, as otherwise there is the possibility of some location having some nasty in it and depleting the chlorine without your being aware of it.

I would want an absolute minimum of 15 minutes contact time with a strong chlorine residual at the end of that time.  Half an hour to an hour would be much much better -- and the water should smell like a YMCA pool at the end of it.  Chlorine test strips and tablets are available for swimming pool maintenance, and are a cheap and easy quick guide.

You may find, even after you blow the system out and rinse it, that you need more chlorine that you might initially think.  Make sure that your chlorine residuals at both the beginning and end of the circulation procedure are at least 3 ppm.

Then drain and refill and circulate some more -- and have the water tested at some reliable lab. for every bug they can think of.

The only problem

@ March 30, 2014 4:03 PM in radiator paint

with any of the metallics -- copper, gold, silver -- is what is called "emissivity" -- that is, simplistically, amount of heat, in BTU per hour, which a surface at a given temperature will radiate.  We use a nominal figure of 240 BTU/hr at 215 F -- steam temperature -- but that assumes an emissivity around 95%.  Metallic paints will drop that figure to as little as 70% -- even lower, if they are clean and in good condition.  This effectively derates your radiation to that figure -- say 150 BTU/hr or so.

You can see this effect for yourself if you have an IR thermometer -- aim it at a regular painted surface and then at a metallic painted one which you know are at the same temperature; the metallic one will show a lower temperature, since an IR thermometer doesn't actually measure temperature, but rather energy radiation rate.

Now then, there are two problems evident with metallic paint.  First, your radiation may wind up undersized for your space.  Second, your boiler may now wind up quite significantly oversized for your radiation.

Or you may have both problems at once...

There have been a lot of threads on painting radiators; look around.

If it''s a crack

@ March 29, 2014 9:20 PM in steam section broke at the top.

there's a remote chance that something like JB Weld might work.  Then again, it's rather likely that it won't hold up to the heat.  If it's really a hole... enjoy the clouds of steam out the stack; they can be rather pretty.  And hope the new boiler comes soon...

Say what?

@ March 29, 2014 9:17 PM in Burnham boiler for Chicago 3-flat

You say you have no steam to the fitting where the top of the LWCO and the pressure gauge and pressuretrol are attached?  Is this with the boiler running?  If the boiler is running, you should get steam coming out of there like mad -- and be careful you don't get burned by it.  Live steam can cause really horrible burns in no time at all.

In fact, i wouldn't run a boiler with fittings above the water line open... ever!

However, if there is no communication between there and the boiler, you do indeed have a problem!  it's safer to do this all with the boiler firmly off, obviously.  Try, with the boiler off, to blow back through the connections into the boiler -- it should be perfectly free.  If it isn't, start poking and find out why; since that is also the connection to the top  of your LWCO, then the LWCO can't see the true water level if the connection isn't open, and that's just not safe.


@ March 29, 2014 7:06 PM in Help! Left water on filling boiler and now...

for the update, Wayne!

Well, let's see here...

@ March 29, 2014 7:06 PM in Help! I have no main vents! + problem radiator

First things first -- that insulation is better than nothing, but more -- 1" fibreglass -- would be much better.

Those main vent locations look OK.  I would definitely put a #2 on the longer main.  A #1 on the short main would probably be OK, but a #2 there wouldn't hurt anything.

On that big radiator -- it probably is a situation of the radiators before it on the line hogging the steam, but until you put main vents on there isn't much point in playing with the radiator vents, as you have already figured out.  Once the main vents are on, then you can start fiddling with the radiator vents.  What you are looking for at that point is the various radiators heating their respective spaces the way you want them, not necessarily that they get hot all the way across (unless you are coming up from a setback; that's another story).

I don't see any reason not to use that Honeywell thermostat, particularly if it is in a better location.  I'm not completely up on the wiring which would be involved, but it shouldn't be that much hassle.

I would imagine

@ March 29, 2014 11:18 AM in Black paper lining wall of radiator

that what you are seeing is "tar paper".  Exactly what kind of "tar paper", though, would be difficult to say -- over the years the stuff has been made in various ways, and, worse, the term is and was used to also apply to tar-saturated felt.

It might have mold, though.  Without looking at it, I'd not care to say.

It's not really a plumber's job to remove -- more like a carpenter, perhaps.  However, to get at it you may find that the radiators have to be moved -- and that is a plumber's job, and likely to be a bear at that.  If there is enough space around and behind the radiators, you might be able to get at it enough without removing the radiators...

Then, of course, there's the question of what are you going to find when you get rid of it!  Older houses are full of surprises.

That branching

@ March 28, 2014 9:49 PM in Boiler Piping questions

to two loops really shouldn't cause a problem; it's common enough that mains go somewhere and then branch.

Nor should the main returns -- although it is a little odd.  On the other hand, it makes it simple to add the main vents, they can go right there at the boiler, which is ideal.

As to that tank... it might be there to compensate for slow returns.  It might also be... who knows?!

Thank you, Gerry and Steamhead

@ March 27, 2014 6:42 PM in Steam Trap - Kelmac Jr. Retarder ?

for chiming in -- I'm not a pro as you know, and it's very helpful when you do!

There are some problems...

@ March 27, 2014 5:24 PM in Steam Trap - Kelmac Jr. Retarder ?

with your near boiler piping, but we'll let them go for the moment.

In answer to your question no. 1, yes, in my opinion you should get a vapourstat and set it as I suggested.  You could keep the pressuretrol as a backup.

Now on question no. 2.  The answer is "that depends".  First, before you do anything else, get your pressure down where it should be.  Then see how the radiators and returns are faring.  If you are really fortunate -- and you might be -- the valves will be stuck, alright, but stuck just about where they should be.  In that case, you will find that very little steam will get out of the radiator, and although the returns may be warm -- indeed, may be quite warm, even as much as say 180 to 200 -- they won't be steam hot.  On those radiators, "it ain't broke", so don't fix it!  Unhappily, you may also find some radiators where this isn't so, and on those, yes, I would suggest that the first thing you do is see if you can persuade the valves to unfreeze, so that you can set them properly.  If that doesn't work, and too much steam is getting in, then you may want to install regular valves -- but you can help matters considerably by also installing orifices (search for orifices on this site, or in your books) which will restrict the steam flow to what is needed.  This may take some experimenting.  If you're still having problems with steam in the returns, then go ahead and put in thermostatic traps -- but I'll bet that by this point in the proceedings it won't be necessary.

On venting.  With vapour systems, it is essential that there be main venting so that the air can get out so the steam can get in.  If you have dry returns, you will need main vents at the point where they end near the boiler.  It will also do no harm to put main vents at the ends of the steam mains, assuming that there are no crossover traps there to do the job.

With those pressuretrol settings

@ March 27, 2014 4:25 PM in radiators hissing from vents, one valve shooting water

the boiler should cutout at not over 2 psi -- not 5 psi.  Check that the pigtail and pressuretrol openings are clear.

Thanks Gerry!

@ March 27, 2014 4:23 PM in Steam Trap - Kelmac Jr. Retarder ?

I suspected that it was a vapour system of some sort -- but I can't keep them all in my head.

That re-emphasis my initial thought -- that a workaround on a trap failed open will be to simply close the radiator valve enough to match the capacity of the radiator.

It also means that the pressure needs to be really low; ideally, the OP should get a vapourstat for control, and set it around 12 ounces cutout and a differential of 6 ounces, at least to start with.

Bing sure doesn't help, does it?

@ March 27, 2014 1:50 PM in Steam Trap - Kelmac Jr. Retarder ?

Came up with  a vacuum cleaner outfit in Australia... sometimes the 'net isn't all that helpful!


Can you get the valves on the radiators freed up a little?  If so, there's a workaround until summer comes...

Which is.  First, get your pressure as low as it can be made to go without the pressuretrol falling apart.  Then run the system and go around to the various radiators when the system has been on long enough for the radiators to get hot.  You are looking for returns -- below the trap -- which are steam hot (you are also looking for radiators which don't heat at all -- I'll get to that).  Not just warm or even hot water hot, but really yeouch hot.  When and if you find one, that trap is not closing against steam.  The trick and workaround is to partially close the radiator valve.  Most radiator valves on two pipe can, and will, throttle the steam to the radiator; the objective of the exercise is to reduce the steam to the particular radiator to just what the radiator can condense.

It is very likely that you may have to make two or three passes around the house to get this right, as adjusting one radiator will affect the others, even at some distance.

If you find a radiator which isn't heating, that means that the trap is failed closed.  If your steam inlets are at the top of the radiators, there is no easy way to work around that.  If the valves are at the bottom, and someone stuck an air vent on the radiator, make sure that the valve is all the way open and live with it until you can replace the trap.  Sorry...

Main vents will help a lot.  Spend a little time with your new books and your system, and figure out where all the mains go.  That will help in deciding what vents to use, and where to put them.

As Bob noted, most of the work which needs to be done you can do yourself, and it's rather fun!

Sounds to me

@ March 26, 2014 9:18 PM in Ideas for 1860's unheated farmhouse

like you're going in the right direction there. They will be a lot more comfortable with the panel radiators, and it is likely that you can integrate them into the house with a minimum of disturbance to the house itself.

PEX is the only way I'd go for the piping; anything else is too stiff and fractious to get around the various beams and braces and who knows what else you are going to run into in there.

I would suggest that you plan on several zones, particularly if the house is somewhat exposed to the wind. It is almost impossible to get a house that age really tight, and if you have zoning so that the various exposures are controlled separately -- as well as conventional zoning such as bedrooms, living areas, etc. -- they will be happier, as the temperatures will be much more even when the wind blows.

I can almost guarantee that forced air will never, ever give satisfactory results in such a setting! Impossible to get it balanced against all conditions. Never mind, as you say, the devastation which putting ductwork in would cause.

Have fun!

Paint remover

@ March 26, 2014 6:39 PM in Removing and loosening painted radiator condensate trap covers

Get as much of the paint off of there a you can before you even try.  Wrenches won't fit properly on a painted surface -- or if you are using a pipe wrench, won't hold.  So get down to the original metal first (comments on the folks with the paint brushes are permitted while doing this!).

Then you can try the usual... keeping in mind that some of the paint will have seeped into the mating surfaces, which makes a dismayingly good thread locker.  Sometimes a little heat can help a lot.

Shifting my comments over here

@ March 26, 2014 10:26 AM in Burnham boiler for Chicago 3-flat

which is a better place for them...

What you really need is a good steam man on the ground to take a look at this thing.  Have you looked in Find a Contractor, by State?  There are some good men out your way.

That said, however, and judging by the high quality wiring around the aquastat and the changeover switch, I would venture that you actually have two problems -- one being a poor control strategy (using an aquastat on the return) which was put in to try to help the other one, which is primary: poor steam distribution.  The clue here is that you said that if you turn the aquastat way up, you do get steam to the cold radiators.

OK.  Until you can get a good qualified steam guy to take a look at this thing, here is what I would try.  First, set the system to run on the pressuretrol only, and set the pressuretrol to cuout at 1.5 psi and cutin at aboud 0.5 psi.  That's the easy part.  Second, trace out all of your steam mains.  Make sure that all of them are insulated, and that all of them pitch properly to drain.  Then check and see if there are any traps from them going into returns -- could be either F&Ts or crossover (radiator type) traps and, if there are, that they are working properly.  Then, and this is perhaps the most important part, check that there are main vents at the far ends of all of the steam mains.  These main vents are critical to allowing steam to get into the mains and on to the radiators; without them, it is almost impossible to balance the system properly.  If there are main vents, make sure they are working; if there aren't, they should be installed.

While you are doing the tracing, take a little time when the boiler fires to see (feel) where the steam is really going, and how fast.  This is likely to give you some clues as to what is happening.  It should be going along all the mains at about the same speed.  If you come to a place on a main where the steam seems to stop, or slow down a lot, look around and see if you can figure out why.

Oh yes -- and while you are waiting for your steam expert to come, order and read at least the book "We Got Steam Heat" and preferably "The Lost Art of Steam Heating".  They're worth the effort.

Does this boiler

@ March 25, 2014 7:48 PM in No steam reaches shut off valves.

also produce your hot water?  If not, there is no reason that I can think of that a steam boiler needs an aquastat.

If there is an aquastat, and it is shutting the boiler off before it can make significant steam, it stands to reason that you are going to have problems with steam heat, no?

As to the unevenness of heat in the building, I suspect the aquastat is not your only problem.  It is much more likely that you have problems with venting -- particularly main, piping, lack of insulation, boiler capacity, or some combination of the above.
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