Install Instructions

Balancing the manifold is the key to having the right heat delivered to the correct loop, zone, or
room. The manifold is the distribuon point where all the loops connect. Depending on design
requirements, each loop will cover a specic area, and subsequently, its length and heat demand will
be dierent from that of the other loops on the manifold. To meet the heat demand of a parcular
loop, rst, ow needs to be established, then, the pressure drop of the worst loops that a pump
can be selected. The pump is sized to deliver the correct ow to the manifold. However, that is not
the end of it. Water will travel the path of least resistance. A longer loop will have a higher pressure
drop compared to a shorter loop, so, given the opportunity, the water will try to go the path of least
resistance, through the short loop. This results in too much ow through the short loops (potenally
over-heang), and too lile ow (never sasfying the room thermostat) in the long loops.
Balancing takes in account the heat demand needed and the pressure drop (that it means the
correct loops ows), and diverts the ow to accurately give all the loops their required amount. All
MrPEX® manifolds have loop owmeters. Use the MrPEX® Design Soware to complete the design,
each manifold and loop will have a target design ow and pressure drop. The manifold info is used
for pump sizing and the loop ow for balancing the loops by dialing in the correct ow on the ow
meters.
Always begin by ensuring that all of the return manifold on/o valves are fully open. Then adjust
the supply manifold owmeters. At rst, remove the red cap and adjust the owmeter valve on the
black base by hand (tools, e.g. pliers must not be used). It is not possible set the owmeter if the
red cap is not removed. Turning the owmeter without remove the red cap could produce ruptures
of the component. When the black plasc base of the owmeter is turned clockwise the ow is
reduced, while if it is turned counter clockwise the ow through the loop increases. The loop ow is
indicated the printed scale on the sight glass. Find the target ow requirement for each loop in your
MrPEX Design Soware printout. When all owmeters of the manifold are seled (normally aer a
couple of adjustments), the red caps can be reposioned. The red ring located on the sight glass is
the memory posion of the set ow, and it permits to reach the set posion when the owmeter
will be closed for maintenance, and subsequently reopened.
If a ow seer valve is used to control the ow to the manifold, rst set the total water ow to the
manifold prior to starng to adjust the individual loops ows.
Balancing the Manifold and Loops