We have a Columbia Boiler with two zones. About two weeks ago we could hear water running through our baseboard heating on the second floor but there was no problem with heat. Yesterday we found that the second floor is not getting any heat, when we turn the thermostat up the boiler starts but the baseboards are cold. The first floor has no problem with heat. We noticed that the expansion tank (Extrol 30) kind of clunks after the boiler shuts down and it never did that before. Also the PSI stays at 0 and does not move even when the boiler starts. From what I have read on hear it sounds like there is air in the system or not enough water in the boiler?

Here is a link to some photos
Boiler pictures by shea70 - Photobucket

 

In the third picture, there is a valve that appears to be closed... I can't tell for sure though it could be a shadow.

That bell shaped thing with the lever on top is your 'pressure reducing valve' ... to the right of that is a 'backflow preventer'... the valve I'm talking about is to the LEFT of the 1156 pressure reducing valve...

Turn off the boiler for a while and allow it to cool to 100F or less... then OPEN THAT VALVE (it's a 1/4 turn job). The handle should be parallel to the pipe. WATCH THE PRESSURE GAUGE... water should feed into the boiler and slow and stop at around 12-15 PSI. If it continues to rise above that, CLOSE the valve again...

Let us know what happens.

 

What is that we're looking at in picture #1 ?

 

That is the back of the boiler it looks like a drain and a pressure relief valve

 

That valve on the left side of the pressure reducing valve does not turn it lifts up (not sure what type of valve that is called)

 

A little background... IF that valve is closed, and you are losing pressure in the system, it could mean a small leak somewhere. Even with that valve closed, the system should hold pressure.

Before you add pressure to the system, since it is already at zero, while you are waiting for it to cool down... See the gray tank? That's your EXPANSION TANK... do you have an ACCURATE tire pressure gauge? Take this opportunity to check the air charge in the tank... on the bottom of the tank is a plastic cap. Unscrew the cap and put the tire gauge on that fitting. If it is less than 12-15 PSI, you need to add air to it with a small compressor, or a bicycle pump. Then, check the boiler gauge again. If the pressure has come up, you need to open a drain with a hose and let a little water out until it is again at zero... and check the tank again... add more air back to 12-15 PSI... repeat adding air to the tank and draining some water (ONLY ENOUGH TO GO TO ZERO ON THE GAUGE!) until the tank stays at 12-15 and the boiler stays at zero.

Next, on top of the hunk of metal that the tank is hanging from (that's your 'air scoop'), there should be a brass can thingy... that is an 'automatic float type air vent'... there is a small cap on the top of it... is that cap tight? it should be loose in order to vent the air from the system. Inspect it for signs of leaking... you probably won't see water, but you may see greenish-whitish corrosion deposits on it...

When you are done with that, the boiler will probably be cool enough to add some water.

 

Can you get a better picture of it?

i.e. more light, closer up, different angles...

 

OK, I see it now... thanks.

 

Just so we're clear, we're not talking about the lever on top of the pressure reducing valve... we're talking about the thing on the pipe to the LEFT of the reducing valve, right?

 

By the way, when trying to get close ups with your camera, look for the 'MACRO' function, and engage that... the close up of the gauge is probably out of focus because of that...

 

added more photos
Boiler pictures by shea70 - Photobucket

 

Can't get a good picture of the guage but trust me its at the end on 0

 

You say that valve 'lifts up' ? Not sure what you mean by that... it's definitely a quarter turn ball valve... you should be able to turn that handle 1/4 turn counter clockwise ... don't pinch your fingers!

 

I thought it lifted up but you are correct it does turn. I will complete the steps you mentioned below starting with the expansion tank tomorrow and let you know how it turns out. Thanks for your expertise.

 

On your air vent... doesn't look as though it's been leaking... that's a good thing. The one that you have is called a 'Duovent' ... the RED cap should be snug, the BLACK cap should be backed open about two full turns.

 

If you need the heat upstairs, you can go ahead and add some water to the system... and go back at a later time and check the expansion tank if you like.

Do examine all the piping for evidence of small leaks too... look for greenish-whitish mineral deposits around elbows, valves, etc...

But, the reason the pressure is low is because that valve is closed...

 

What's with the zone valve power head on top of the boiler? Other problems with that also?

 

We just bought the house a few months ago but the previous owner said it was left by the last HVAC contractor that cleaned the system. No problems that we know of

 

He might have also left that valve closed by accident! OR, it might be closed because of a defect in the pressure reducing valve. You CAN run the boiler with it closed, but you have to keep an eye on the pressure gauge in that case...

Ahhhh, just bought the place... I was wondering why there wasn't a lot of 'stuff' in the basement! don't look like mine, I can tell ya that!

 

I'm just waiting for the water to cool and then I will open that valve. Could the reason why it is shut have to do with our domestic hot water being heated through the coils?

 

No, nothing to do with that.

There are two schools of thought on whether the feed valve should be left open all the time, or closed... even the manufacturers can't seem to agree. Bell & Gossett says to fill the boiler to the proper cold pressure, then close the valve. Watts (and perhaps Taco) both say to leave the valve open.

There's lots of reasons on both sides of the argument...

Leaving the valve open could 'mask' a slow leak that might go unnoticed for a long time...

Closing the valve could lead to ultimately running the boiler dry...

On my personal system, I run with the valve closed, but I walk past and glance at the pressure gauge several times a day... it's in my 'traffic pattern'... for folks who rarely look at their boiler, it may perhaps be best to leave it open...

It's a good practice and habit to get into to look the system over from time to time...

 

Okay I opened the valve and the pressure is up to about 10-12 on the boiler but still no heat on the second floor. I used a tire pressure gauge on the expansion tank while the boiler was not running and running and it didn't even measure. Of course I can't find our pump to put air in the tank so I may have to run out and buy one.

 

If you have no pressure in the expansion tank, the next thing you will be telling us is that your relief valve is opening because the pressure goes over 30 when the boiler is heated...

You should only attempt to check or charge that expansion tank when the BOILER PRESSURE IS ZERO... you can not do this properly with the 10-12 in the boiler, so you will have to drain that out again...

After you get the tank pressure straightened out, and the boiler back to 12 PSI, you will need to get the air out of the upper pipes.

Look inside all the baseboards. You may find air bleeder valves inside them... usually at the elbows where the pipe goes into the floor.

More about this later, first get the expansion tank charged properly.