taco 007-f5

Unfortunately, these pumps, like all pumps, can last for years or seconds. I have seen them come out of the box and die the first day. When I installed my stove, the dealer advised me to get a second pump as a backup for this very reason. Nice to have a spare so you can swap them out fast and get your heat back. Especially on the weekend.

make sure you have it with the motor horizonal and have it as low as you can to keep from cavitation. The biggest killer with pumps is cavitation as water is the bearing. With open systems it is even more important. You need to have at least 5ft of water above the pump.
leaddog

Before you throw that pump away, give it a bench test and physically spin the impeller while under power. If it works then keep it as a spare for emergency use. These little pumps don't have much startup torque and get jammed quite easily. Was the motor shaft horizontal?

I've never heard of a max head pressure limit, I think the more the better (less chance for cavitation)

A 15' head of water will create only 6.5 psi & this will help to prevent cavitation, the friction losses in the piping to and from the house is what the circ. must overcome. More than likely the impeller got jammed with something, maybe try to free it up to save as a backup.

fabguy01 said:

back on wood heat , yes the pump shaft is/was horizontal, it is below the boiler so it gets plenty of water without cavitating . the pump was so hot when i went to replace it burned my finners :bug: and the pump shaft is siezed tight. how much head pressure can these pumps tollerate? my water to air hx is about 10 feet above the pump and about 5 feet above the top of the boiler

Click to expand...

http://www.taco-hvac.com/uploads/FileLibrary/curves003-008.pdf

Follow line #5 dark green, in an open system you may need a bigger pump based on your criteria.

I've had them run for 18 years. Never had one fail yet. Elevation typically doesn't equate to head pressure, because it's balanced by the water coming back down. Head pressure is determined by the flow resistance of the plumbing components in the loop at the flow rate the circulator can push through that loop - it's actually the intersection of the head loss curve of the plumbing and the pressure / flow curve of the circulator.

As long as you have enough pressure to prevent boiling at the pump inlet, these seem to tolerate being run dead-ended (zero flow). I think they only develop a maximum pressure differential of around 4 or 5 psi.

the motor may be fine, just the cartridge needs to be replaced. Replacement cartridges are available for Taco, although a complete new circ can often be found for less money.

Some times the shaft will free back up when they cool down, don't toss it out just yet.

hr