Boiler issues can anyone help.

[caper150]

I am so close to finally having my in floor heat up and running 100% but I am having trouble getting the water to flow right. I have a primary and secondary loop with a pump on each, the water gets hot but it just doesn't seem like it want to flow through the primary loop. The pump is working it spins but it just doesn't seem like it's going fast enough. I can hand pump water through the loop and it's doesn't seem like there is any air in the system. Anyone have any ideas whats stopping the water from flowing back into the boiler??

 

[brewchief]

I am so close to finally having my in floor heat up and running 100% but I am having trouble getting the water to flow right. I have a primary and secondary loop with a pump on each, the water gets hot but it just doesn't seem like it want to flow through the primary loop. The pump is working it spins but it just doesn't seem like it's going fast enough. I can hand pump water through the loop and it's doesn't seem like there is any air in the system. Anyone have any ideas whats stopping the water from flowing back into the boiler??

Some pics of your piping would be a start

 

[napaAl]

What size pumps are you using?

 

[caper150]

Here are some crappy cell phone pics of the primary loop

Secondary going into the in floor pump,

It's a Nibco Radiant panel

Questional Pump

Sorry not sure on the size of the pumps.

 

[nehog]

Can't say for sure, but that pump looks a bit small... Can you see if there are specifications on that end plate or the blue label?

 

[stingry]

Sorry not sure on the size of the pumps.

SIZE MATTERS!!! Your pump needs to be sized according to the desired flow rate and the head loss thru the boiler. All pumps are not created equal, it's the pump curve that is most critical in sizing a pump correctly, not just the rated hp. You need to check this to make sure your pump is sized correctly. The boiler specifications should have curves for determining the head loss for the required delta T, this in turn can be used to size the pump for the desired flow rate.

Better pictures or a diagram of your piping would help.


Cheers
Steve

 

[caper150]

Ok thanks guys I'll check that stuff out when I get home from work. I assumed the pump would work since it came with the boiler when I bought it.

 

[ManCave]

The pictures are so bad its hard to tell what you have there. Can't see some of the piping, etc... too dark and fuzzy.

Anyway....

If the vertical pipes in this photo are your closely spaced Tee going to the heat exchanger or heating loop, then the problem is you have your secondary pump in the wrong place. Your secondary pump needs to be in the vertical leg of that piping on the input side so that you're pulling water off the primary loop and pumping it into the HX. On the return side of the secondary, you need to have a check valve to prevent ghost flow.

 

[Bondo]

Ayuh,... In the very 1st picture, the ball valve by the pressure tank is Closed...
Of course it ain't gonna circulate...

Ditto on the 2ndary loop...

 

[CARS]

Ayuh,... In the very 1st picture, the ball valve by the pressure tank is Closed...
Of course it ain't gonna circulate...

Ditto on the 2ndary loop...

Good eye!

 

[caper150]

ok sorry for the crude drawings but the red arrows are the primary loop and the green are the secondary and indicate the direction of water flow. In the picture you can see the valve for the shut off for the primary. Right now it's closed and the boiler is running and heating, if we open it the water doesn't seem to want to flow back to the boiler. tried a different pump today but that didn't help any.

And yes I knew the valve by the pressure tank was close, was trying to try different ways to get all the air out of the system with a hand pump.

 

[napaAl]

Did you open the screw on the primary pump to see if it is spinning?

 

[caper150]

Did you open the screw on the primary pump to see if it is spinning?

yes, I am somewhat thinking it's all in that one diverter ball valve, but not sure.

 

[ManCave]

My OWB is 250 feet from the house. I had a problem with air in the line and could not get it to pump through to the boiler. The pump would make a surging noise but wasn't really pumping anything.

I ended up pulling the pump out and flipping it 180 degrees so that it was circulating the opposite direction. I let it run overnight. Next morning, I put the pump back to the original position and it has worked fine ever since. In my case, I must have had air that would only purge when pumping the other direction.

Sounds like you have something similar going on.

 

[koditten]

Those lines going to the secondary loop are too close together. Most installations require at least 12" between the supply and return for the secondary loop. I put a valve between my supply and return to force water to go were I want it.

If you down load the installation manual for your boiler, it will have diagrams for a proper set up for a primary/secondary loops. Most boiler manufacturers have the manuals available. Very good info there.

KO

 

[tdkkart]

A couple people in this thread need to read about "closely spaced T's":
http://comfort-calc.net/primary-secondary_piping_tutorial.html

It appears as though the OP's boiler system was designed as a primary/secondary system with closely spaced T's, which isn't working correctly. A couple inline flow meters would go a long way to diagnosing the problems.

On the other hand, a couple people are offering advice which directly contradicts the original design.

 

[ManCave]

The OPs system is using a primary/secondary loop. The secondary loop uses a closely spaced tee. That means the input/return on the secondary loop has to be close together. Its by design.

What I see may be wrong with his system is on that secondary loop there HAS to be a pump. (I didn't see a secondary pump in the photos) The one main pump on the primary loop will not push water through the secondary. The whole point of a closely spaced tee is to prevent such ghost flows.

 

[tdkkart]

It looks like there is a 2nd pump(4th picture in post #4), however it's installed horizontally, which means it could have a big air bubble in the pump housing, which will cause a problem.

 

[caper150]

Yes there is a second pump for the secondary loop, that pump is the one that came mounted to the panel that is for the loops in the floor, I never mounted the pump on the panel thats the way it came from the factory.

 

[bmcdowell40]

My boiler install manual, which is a Quietside wall hung condensing boiler, called for the closely spaced tees and the primary/secondary loop setup. I had the same problem, couldn't get it to flow properly and get heat upstairs. What it turned out to be was that the secondary pump was too stong and simply caused the water in the loop to circulate and wouldn't allow any new "hot" water to enter the loop. I ended up scrapping the close spaced tees and piping the return sides of my heat loops directly to the return side of the boiler.

 

[ManCave]

I did the math to size my pumps properly (as close I as I could figure, without knowing what I'm doing) and then I bought the 3-speed Grundfos pumps (Menards carries them) so that I could tweak the flow rates as needed.