Piping a wall hung boiler

Ron Schroeder_2

I haven't run across this yet but I am sure that I will.

It seems that some of the wall hung and other high tech boilers come with internal circulating pumps some even controlled by the boilers logic. How do you deal with "Pumping Away" when the pump is inside of the boiler package?

Ron

hydronicsmike

Primary / Secondary

Pipe the wall hung Boiler into the System Loop with two closely spaced tees (also called Primary/Secondary) or Low Loss Headder to isolate the Boiler from the System Loop. Let the Wall Hung Boiler operate the Boilers Pump (in most cases) and take over on the System Loop side.

In most cases, the Boiler Pump is not the right Pump for the System, but for the Boiler alone.

For multiple wall hung Boilers, use the Paralell Primary/Secondary Piping arrangement.

Hope this helps.

Mike

Ron Schroeder_2

Hi Mike,

What kind of pump do they use? A normal flanged one?

One thing that I briefly thought of was to put a tee on the pressure gauge fitting and add the expansion tank there.

Ron

Dan_16

On my trinity boiler I used a taco 011 for the primary with 2 oo7 pumps for my secondaries. I installed them with the isloator flanges with built in ball valves. In regards to the expansion tank I used a 1 1/4 spirovent which has a 1/2" fta and hung my tank below inside of the primary loop and then tied my make up between the two with a T.

Steve Eayrs

Is this a exp. tank location question?

Or a pump question?

Some of these boilers (Vitodens for instance), have the internal pump on the supply, and if the floe rate is within the specs. the boiler pump can handle it, and ept. tank will most likely be on the return.

Others have already mentioned the p/s piping/pump needed if the demand can't be met by the internal boiler pump.


Steve

Ron Schroeder_2

It sounds like relying on the head pressure of the primary loop being so low, it doesn't matter where in the primary loop the expansion tank is.

Ron

Uni R

Piping a wall hung boiler

The expansion tank doesn't even need to be in the primary loop. Check out the installation manual for an Ultra and it is on the secondary loop.