Please help me troubleshoot a residential hot water heat system!

[micrologix1500]

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 restricted?!

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!

[louie]

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.

[Paul Franklin]

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.

HTH,

Paul

[RBM]

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 properly bled.

[micrologix1500]

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 with me!

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 :)

[Edwin Pawlowski]

Is there a coupling between pump and motor? Could be the motor turning and the pump is not.

[HeatMan]

In-line...

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 wonder.

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.

[Tony Hwang]

Hi, Air in the line? Need bleeding. Once happened at my daughters place(high rise condo) Tony

[zero]

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 boiler.

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 boiler?!!

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 day.

-zero