Hello and TIA, I've been asked by a coworker to help figure out why his
house is not getting any heat. Maybe the word got out that I've
installed a few forced-air furnaces, or maybe he just thinks that
because I'm the supervisor of a skilled trades dept. I must be somewhat
handy! Well, the jury's out on that one but I'm definitely not one to
shy away from a challenge!
Anyway.. The "trunk lines" leading in/out of the boiler are getting
REAL hot.. No problem there. The gage on the front of the boiler reads
approx. 25 lbs. and 190-200 degrees F. This is probably above the
intended maximums of the system, as the relief valve is dripping. The
pump motor is turning, and presumably functional. I'm assuming all the
pipes are hooked up properly, but that can't be taken for granted as
there is some construction going on in the house and much of the copper
tubing does look to be new. Further complicating the problem is the
fact that this guy, nor his family, speaks much English! Unfortunately
I don't speak Bengali (the language spoken in Bangladesh) so I'm pretty
much on my own trying to figure out the situation..
I tried tracing the path the water travels in, but I got a bit
confused.. There are brass "Tees" in the main pipes that upon further
examination may not actually be a Tee like I'm used to.. It looks like
one leg of the Tee might actually be closed or atleast greatly
The main symptom is that the pipes that branch off the "trunk" and go
to the baseboard radiators upstairs are cold. It doesn't appear that
there is any circulation through the plumbing above the basement. I've
googled a few older threads on baseboard heat and think that air must
have entered the system somehow, and must be bled out before he'll get
any heat. Am I on the right track with this?
If so, could someone briefly go over how this is (safely) done? It
appears that there is some sort of cap/plug in the water line, close to
each baseboard radiator. Do I need to open these? Should this be done
with everything running? One of my concerns is, as this is a pretty
OLD system and the plugs are pretty crusty, that I'll crack one open
and not get it to seal up properly when I'm done. I guess that's just
a risk I'll/he'll have to take though!
Anyway thanks again for any replies, I do hope I can help this guy out,
as the company doesn't pay the hourly workers much and I try to help
them out as much as I can!
On 20 Oct 2005 22:34:33 -0700, firstname.lastname@example.org wrote:
All right, I'll take a quick crack..I'm sure Heatman and some of the
others will chip in too.
It sounds like you have a main loop from boiler outlet to inlet, and
several branch loops that are tee'd off the main loop, run up to some
radiators, and rejoin the main loop farther down. It also sounds like
the system uses diverter tees, which, as you describe, are like
standard tees but have a partial obstruction or scoop in the main
path. This forces, or attempts to force, water to flow through the
branch part of the circuit. But you have no flow through the branch
circuits, otherwise they would be hot. As you surmize, a common
reason for this is for the branch to be air locked.
There is usually one or more air bleed valves for each branch. They
are often small, maybe an inch high, and have a small spout. They
often have a recessed hex shaped shaft that requires a little radiator
"key" to turn, although some just require a screwdriver.
The general idea is to open the bleed valve and leave it open until
water comes out steadily with no sputtering. You can do it with the
system off or on, I usually do it first with the system off. If the
bleeds are rusty, soak them with a bit of WD-40 or the like before you
attempt to open them. If one breaks, you are in for a bit of a job.
Bleed all the branch circuits, and try it out. It's a good idea to
bleed them several times over a few days as more trapped air makes it
way to the high points. If you can't get water out of the branches,
you may have thermostatic valves or zone valves that are off..
And since it sounds like the system has been neglected, I would
strongly urge you to urge your friend to call a pro to inspect it.
They can make sure the temp and pressures are right and that the
burner is adjusted properly and burning safely, and that all the
components are working properly, especially the safety systems. I
realize from your description that money may be a problem, but urge
them to get a pro as soon as they can.
I agree with Paul. If the main loop off the boiler is hot in and out, and
you can determine that the pump is actually pumping,(not just circulating by
convection). This sounds like a "venturi" system, as he described and the
most likely scenario is that the boiler was drained to do some work and not
One simple thing to check for also that I had to run into in my last
house with a hot water system: Check the return lines where they join
back up with the main return "trunk". Somewhere near there may be a
balancing valve. Probably looks like a ball valve but might not have a
handle and would be turned by a large flat screwdriver. If someone's
been "adjusting" these, they could very well have closed off some of
the branch loops. There may or may not be these valves here or on the
supply end of the individual loops. Just something quick to check for
before you start tearing your hair out.
Once again, thanks all for your help. I'm glad I waited to ask before
doing anything.. I might have messed with the wrong fitting and caused
us all a lot of grief!
On one end of the finned-pipe "radiators" is the fitting that I
described.. Under all the crusted sediment, it looks like there is a
hex cap on top that I thought might be to bleed it out. On the *OTHER*
side, however, is something much like Paul described: It has a
square-drive stem on top, much like a commerical/institutional water
valve. I think THAT is where I should bleed it out (after I go to the
plumbing store and get a "key") And I'll remember to take the WD40
As for if the pump is really turning or not.. Well, I can't vouch for
there actually being water flow in the pipes, but the intense heat in
the main "trunk" indirectly suggests to me that the water is flowing
under pressure. The steep temperature gradient in the branch plumbing
makes me thing there's something else wrong other than overall lack of
system flow. The temperature goes from too-hot-to-touch to
room-temperature over 2 feet of pipe. The entire run of trunkline is
in the "too-hot-to-touch" range :)
On 21 Oct 2005 07:29:00 -0700, email@example.com wrote:
But ya know what?.... The best way you could help him is be his
translator and find a reputable company to come in and service his
Leaking Safety Relief Valve.... it needs to be replaced ASAP.
A trained/experienced service technician will catch all things and
categorizes what's what. Is it unsafe? Is it just inefficient? Will
it just stop working when part "xyz" goes bad or will it be a runaway
Contractors Liability Insurance takes care of this big $$$ lawsuit.
Proper licensing helps to make sure the qualifier has the basic
knowledge to perform this type of work. (no jail time)
If anything happens to this boiler form this day forward, (until
somebody else or a qualified company works on it or even turns it off
or on) _YOU_ are the last one to repair/alter it, and all things will
point to you.
The truth doesn't matter. You can explain what you did to it step by
step all day long, it's not about that. You're the _Fall Guy_.
And one more thing. Ones English improves dramatically when the Fire
Marshall is asking them, "who last worked on your boiler?" in front of
their burnt down home. (hopefully with no fatalities=no jail time)
I would tell him his boiler needs to be serviced, and then be his
facilitator. Treat his money like it was your own, and call it a good
Can't help much on the langauge barrier, but I may be able to help
otherwise. The dripping releif isn't a good sign.
Could be a mono-flow system. Do the tee's have a ring on them? Are the
tees more or less below the radiators?
You could be. I've heard of a lot of systems seem to let a lot of air int
he system, but I've never seen one like that.
Do you know, for sure, that all the valves are open and the circulator is
running? The hot pipes near the boiler being cool further away make me
I'm guessing you have manual air vents. Be very careful because they might
not seal back off if you open them. If they are crusty, that could mean
they were leaking slightly to begin with.
You can also try the Wall. http://forums.invision.net/Main.cfm?CFApp=2
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.