Noisy Taco pump

JBB

Question; My Taco pump is noisy the way it is currently installed.The out flow from the pump goes into the water heater drain port. Does anyone know if the drain could be a one way out that cannot flow in? I purged with water thru the system, and the pump is quiet. When I close the water flow, the pump makes a surging noise. Should I use the water heater hot and cold for the closed hydronic loop setup? This I replaced in system that worked well until I had to replace the water heater.

EBEBRATT-Ed

Could you post some pictures so we can see what is going on?

hot_rod

is this a DHW recirculation pump?

JBB

JBB

Yes, for underfloor heating.

Grallert

Are you also getting your DHW off of that water heater?

Larry Weingarten

Hi, If there were a valve in the horizontal line at the heater drain, you could close that and really flush the lines, removing all of the air. Without that valve, it's hit and miss. 😐️

Yours, Larry

hot_rod

does it do the hot water also? Seems like a lot of lines connected to the tank? T Wed o on top one on bottom

Usually hydronics has a supply and return.

JBB

Larry, there are isolation valves on each side of the pump. When I ran the water thru the system, I ran the pump also. The pump flow is thru the water heater drain, and out thru the hot inlet of the water heater. Should these be reversed?

JBB

Bob, see the above comment. I will make a sketch to clear things up, and post it

The home's hot water and the underfloor hydronic system are two separate water heaters.

hot_rod

Most water heaters now have “heat trapper” nipples on top. Basically a small flapper or ball inside the nipple to eliminate gravity flow. It acts as a weak check valve .

It may be enough obstruction to starve the pump.

Larry Weingarten

"Larry, there are isolation valves on each side of the pump. When I ran the water thru the system, I ran the pump also. The pump flow is thru the water heater drain, and out thru the hot inlet of the water heater. Should these be reversed? " … Hi, It looks like the heater drain can get water both through the pump and from the tank. It's simpler for water to flow from the tank. If water could flow only from the return line and pump, household pressure could be the driver, rather than just the small pressure the pump can create. This will remove any air from the lines. You may be surprised to get discolored water as well as it scrub the lines that have only seen slow flow. I've been in this position many times and adding the valve has always worked.

Yours, Larry

JBB

Ɓob, there are these on̈ both hot and cold inlet ripples. So, this would restrict the flow? Can I remove these, or just replace the ripples? Sounds like this is the problem.