Taco 3350 Auto Fill

John White

I'm on this first thing Monday. jw

Rob L_3

Taco 3350 Auto Fill

Anyone else use the Taco 3350 1/2" Automatic Fill Valve? We have had way to many tech calls on it this year to count for me to fell confident about using it any longer. If the water pressure will drop, usually the valve will try to keep 12 psi in the system but for some reason this one isn't working like it should. It is only working in the "fast fill" function. We called our vendor and they said the "auto" portion needs to be "exercised". Seems odd as we never had to do this in the past.
Any other auto fill to recommend?

Thanks,
Rob

Unknown

Does it

auto feed at all?, or do you need to open the ff at any lower pressure. Although the setting may be 12psi, the system usually has to drop to 8 or so before it actually starts to feed then it levels off.

Rob L_3

It is

Not filling in the automatic position. Too many times to count where I have got the call where I am told the pressure is 0 psi. We do our due diligence checking for leaks,etc making sure that isn't it but the valve doesn't want to auto fill when needed.

Unknown

New one

on me Rob. It should feed of course,, hope you have a LWCO in place!
Is this only one unit, or do you have others?
Also, if the pressure drops to 0 psi, I wonder where it`s going?
Not trying to undermined you, just curious.

Dave

Rob L_3

It is

Happening on new closed loop radiant system installs where there is still air to work its ways out of the system. It usually takes a few days or longer depending how much tubing is in the system. The "auto fill" valve should generally keep up pressure when trying to displace small amounts air with new fill water, but just not happening with this valve.

Thanks for your input

Unknown

No prob Rob,

you obviously seem to know what you`re doing,, but I have to ask, are you "pumping away" from the feeder?
Again, not trying to be smart, just understand.

Dave

Rob L_3

Yes

We use standard primary/secondary boiler piping and always follow the "pump away" method.
I would think maybe we did something wrong if it was just one instance, but multiple times on all different jobs does not make sense.

ScottRW

Taco Fast Fill

Funny this should come up. I had a problem with one recently. Client was complaining of having to fill the system every day. Pressure was dropping below 8psi. Finally popped the cap and turned the brass valve inside. Pressure went up and haven't had any problems since. Seems that the device is not set at 12psi coming out of the box.
Scott

Joe Mattiello

The Taco 3350 Cartridge style PRV is factory preset to 12 psi. However, if changing the pressure is required, you need to pop off the cap, loosen the slotted screw, turn the knob counterclockwise to decrease, and clockwise to increase the pressure to satisfy your system requirements. After successfully adjusting the pressure, the screw then needs to be retightened. This is very important to maintain the pressure; if left loose, the system pressure will vary and can drop without the valve auto filling. Perhaps the screw was loose? Truthfully, the loose screw is the only obvious reason for the valve not maintaining pressure. If you continue to have problems I encourage you to contact me directly, and I will send you a new valve in exchange for the problematic valve so engineering can run some diagnostic tests. Please advise, if you have additional concerns with the 3350 or any other Taco products.

Joe Mattiello
Technical Support Engineer
Tel. 401-942-8000 X 484
Fax. 401-942-2360
1160 Cranston St
Cranston, RI 02920
joemat@taco-hvac.com