No flow in baseboard

Kevin_11

Are you using power robbing thermostat with a taco zone valve?

Franky

No flow condition in baseboard

I have a section of BB that will not get hot.
There is no flow.
The developed length of the line is appx. 100 ft from the point it enters the apartment.
It goes up and down and all around through the apartment.
The pipe size is 3/4".
The first several feet in the apartment gets hot.

I am thinking about installing a pump at the beginning of the room & trying to push the water through the loop.
I am also thinking about adding some baseboard covers and eliminating some of the up & down to shorten the developed lenght and reduce the pressure drop.

What do you think?

Dale

I think air

While you probably have an air block I guess we would like to know what piping system you have. Baseboard is usually series loop and if this is so a crushed pipe or closed valve anywhere in the loop will stop flow. What controls the thing? Many baseboard runs are zoned to run from one pump or one zone valve. Where I live what you describe would usually be a closed zone valve. What is the pressure in your boiler? A few years back I had a complaint just like yours where the boiler pressure was about zero from a bad expansion tank and a bad feed valve. Part of the house was ok but one part cold. When did this start, did it ever work? some baseboard runs have the zone valve hidden under the sheet metal cover and in a room that's connected to other rooms. Some apts. are fed off a very long loop with a 3 port zone valve allowing water to enter. This stuff isn't rocket science and if you keep giving more information the answer will surface.

Franky

No flow in BB

AIR is not the problem.
If you blled loop you do not get air.
The water gets hot & immediately goes cold after.

The apartment is feed from a two pipe system.
The unit is basically a loop between the supply & return riser.

ScottMP

Frank

Is this a zone valve ?

Have you replaced it ?

How about the pump capacity ?

If a zone valve is it turning on the pump ?

By the way, when you bleed the loop what are using to isolate it ? If its one of those small butterfly type valves they s#@K. Is the flow your getting coming from the baseboard lop or the main ? Is the whole loop getting hot when you bleed it ?

More info needed.

Scott

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Franky

No flow in baseboard

Boiler system controlled by outdor reset control.
Pumps are constant circulation.
System has B&G air sep with 1/2" spiro top.
Main supply & return is 2" copper.
Apartment supplied by 2" x 3/4" tee in ceiling.
Apartment has ball valves at beginning & end.
When you bleed you do not get air.
Whole lop gets hot but immediately gets cold after.
I think the main problem is that the pressure drop across the loop is too great for the system pumps to overcome.
The real question is what is the best way to overcome the drop & restore heat to the room?
Do I install a pump & try to push it through?
Do I go up into the hallway ceiling and install a mono-flow tee in reverse & try to divert the water that way?
How do I improve the flow??
What do you think???

Unknown

I think I'd start with the pump curve.

I'd check to see if the pump can be expected to move all of the water in the system. System curve versus pump curve, and GPM enough for the BTUH load at the actual temperature difference.

Noel

Dale

Now that some data is available

If you mean the apt. is supplied from the ceiling to be that it is down fed from the ceiling where the 2 inch runs then you need diverter tees at a minimum or a small pump. You could try a valve in the 2 inch between the 3/4 inch tees and close it slowly to see if the delta P gave you the heat you wanted but you'll probably need a pump on the 3/4 inch line to the apt. A bigger pump on the system won't solve the problem. Since you only have a 100 foot run in the apt the smallest pump you can buy would be the choice.

nick z.

Think like water

If you were the water would you leave the 2"pipe to go into the 3/4? I would try a mono flo T, maybe one on each, supply and return. At least you don't have to worry about T going bad on the coldest day of the year.