loop hot water system making gurgling sounds

Rich_15

Hi,
I have a loop hot water system (forced hot water). The second zone only (upstairs) is making a loud gurgling noise after the heat is on for a bit. You can hear the water rushing through the pipes. What's causing this? I've been in the house 15 years and this is the first time ever.

David Sutton_3

more than likely

there is air in the pipes, have you had some work done on the system?, you should have it purged out. to much air can stop the circulation of the hot water in the pipes, call for service on monday....David

John_26

You may also just look for a bleeder on the heating register. It will possibly look like a bolt with a screw inside it and a little nozzle coming off of it.

Loosen the screw and let the air out until water spurts out. You may do this a few times over the next few days as the water heats and cools.

Glenn Harrison_2

May also be loosing pressure

You also need to check the pressure of your boiler. Normal is 12 pounds for a 2 story house. If it gets low you can have flow problems to the highest point in the system. Also, if it's low, you need to figure out why it's low, most likely due to a leak in the system. You also want to make sure that you maintain 12 pounds of pressure when you bleed the system. If the water pressure reducing valve has not been exercised in a while it may not open to replace the air and water that is removed when you bleed the lines.

Alan_2

re - If the water pressure reducing valve has not been exercised in a while it may not open to replace the air and water that is removed when you bleed the lines.
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Well....I may be encountering this after I refilled the system in our rental today. (original fill valve dating back to the 50s).
The fill valve worked fine when refilling the empty system and also when I opened the passage into the expansion tank.
It also worked fine when I released large amounts of trapped air during the fill.
However, I can't seem to completely top off the system and there is a slight trickling noise in the flow.
Can I try the fast fill lever while the system is cold and try to push out the air ?
(I ended up replacing a B&G fill valve/reducing combo in our house and this solved many head scratchers.)

Glenn Harrison_2

If I'm understanding you correctly...

Your saying you have a rental property that has a 50's vintage fill valve, is this correct? If so, I doubt it has a fast fill lever on it. It may have a bypass valve that could be used to boost the system pressure. I would definately replace that fill valve as it may be plugged, restricted, and the rubber parts inside are most likely dried out and just waiting to leak. Get a new valve so you know you are filling to 12 pounds of pressure, then see how the system "tops off". Also, is this rental a two or three story building? If it's three, you will need about 18 pounds of pressure to get the water to the top, in which case the fill valve will have to be adjusted to 18 pounds

Alan_2

Glenn -

Thank you for your helpful suggestions.
Yes, it is probably due for a replacement, which is what I ended up doing at our house (which now has a B&G F-8 dual unit valve.)

I may be mistaken that it's the original fill valve from the '50s.
The house itself is just a two story ranch, the same size as our house which runs at 12 lbs.

The old valve(s) is a two part dual unit that is gray/gold in color - the second one has a lever that can be lifted and there is a discharge hole underneath.
I need to contort myself behind the boiler to get a closer look at the lettering, etc. and will also try a light tapping (as mentioned by another poster) to see if I can get it to function normally for the time being until next time the system can be down.

The valve did allow the water to fill the system and stopped at around 12-lbs and opened again when pressure was relieved while bleeding.

Thanks again for your reply.

Alan_2

Glenn -

Upon closer inspection with a bright flashlight, the dual unit is a B&G reducing and relief combo.
It is red, actually, not gray/silver as I first thought.
Tucked behind the boiler in a dark corner it was hard to tell.
Anyway, the strainer will be checked.