Package Rooftop Unit-HW Coil not Heating

John West

We are talking about a Large Rooftop Heating -A/C unit--There is an Main Hot Water Pump in the Basement--There is an Booster Pump on the 1st Floor.
There is an Bladder Tank in the Basement with an Air Needle valve on top.
There is about an 30-40 Foot up to the Unit.
There is an 12 PSI PRV.
The Booster Bearing assembly was replaced and now the Coil will not heat--We have tried Bleeding air from the top of the coil.
What would be acceptable Pressures to have upstairs at the coil?
Bleeding from the return--will get hot then turn cold again.
Thanks for any help.

[Deleted User]

the bearing was replaced

and that's when this no heat started? or.....was there no heat and the booster/bearing was thought to be the problem?

tim smith

Regarding pressure etc

What is your pressure in basement? I would say you need 24 psi or so to get it up to coil. At coil you should have around 5 psi. Do you have water at bleed at coil? If so, maybe whoever replaced bearing assy did not see wear or did not get the impellar installed right and you are not pumping. Couple ideas? Tim

scotty_3

hw coil

check pump rotation if you unwired it to do the bearing job...if not you got more air traped some where

[Deleted User]

pump rotation?

1ph motors will run backward if you reverse the wires?

tim smith

No on that for single phase, unless

you are talking about the internal wiring board, some 1 ph pump motors are reversible on the connection board but just reversing incoming leads does nothing for rotation. Also some of the series 60 B&G pumps that were almost identical did have different rotations. Easy to verify now that it's on.