baseboard on monoflo system

lisfjoe

I have a customer with no heat from a 3 ft piece of baseboard where there was once a convector on a monoflo system. Is the cause of no heat due to the excessive pressure drop of the baseboard?



How could I correct this situation?

Unknown

was the

Was the baseboard installed without vent???

lisfjoe

it has a vent

but i get no air, but can't tell if vent is on supply or return side, though it really shouldn't matter when the circ is off, right?

JStar

Baseboard

How far apart are the venturi tees? What size, and how much piping to the baseboard?

lisfjoe

3 feet apart

each run is about 3 feet long of 1/2 inch tube.

Paul48

No Flow?

Did you verify no flow? Three feet of  baseboard vs. a convector is "no heat".

billtwocase

air

You either need to bleed the baseboard, or open a closed valve. You should be able to determine if the bleeder is on the supply or return. If it is on the supply, with the circ off, lift up the bleeder end of the baseboard while bleeding it. Air rises

Steamfitter66

Is the baseboard warm?

If so you have flow. Whats the heat loss of the room?

Whats the heat output of the baseboard at your systems water temp?

Those 2 things will answer your question.

lisfjoe

re:no flow

how can I verify no flow? Except that the supply and returns don't get hot, which I assume that verifies no flow which really was my original question. Why no flow? Is it because of the pressure drop or air?



Also, 3 feet of BB = 1500 btus. Maybe not enough for the room but pipes are not hot.

Paul48

Sorry

Wasn't sure if you had put hands on the system,, or were just wondering about a "no heat" complaint. Like removing a cast iron radiator and replacing it with a section of BB, I could see a homeowner complaining of no heat.

lisfjoe

thanks guys but

still no answer to my question but does 3/4 tube have that much more pressure drop than a convector to cause no flow? I am now thinking it shouldn't have and my problem is probably air. Any comments?.

Weezbo

well,

rjb mentioned ,you probably need to get rid of the air and give it another go ...

heat should arrive at the emitter when you get that happening .

it may not produce much heat even at that due to it being possibly less of a heat emitter than the pipes transmitting the heat to the emitter ,..in the overall scheme of things within the building envelope.

Weezbo.

Steamfitter66

I have worked on quite a few monoflow systems

most of them installed in the 60s and 70s. most single stories had no coin vents and pumped on the return yet would work the air out of the system after a good initial purge.

Are you sure the T are installed properly....

http://websupport.completewatersystems.com/entries/21702433-Monoflo-Know-How-From-B-G

Jason_13

Air

You probably have an air lock. I bet one of the pipes does not run uphill all the time. Add a purge valve.

See comfort-calc.net,click on general hydronic sand than scroll down to monoflo bleeding.

SWEI

It also helps

to lower the surface tension of the water.  Most hydronic conditioners and cleaners contain a bit of surfactant along with their inhibitors, but if all else fails you can add a bit of clear dish detergent (Dawn, Joy, etc.)

lisfjoe

thanks for all your suggestions

I will let you know the outcome.