007 Gone Wrong

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Eric Johnson

Eric Johnson

Mod Emeritus
Nov 18, 2005
5,871
Central NYS
I had a Taco 007 that wouldn't pump water and I had another one with fried electricals. Between the two, I have a pump that should work.

Not sure what happened to the impeller to the right. I ran it in a potable water application for 7 or 8 years at temps that routinely exceeded 200 degrees. But the bearings are still OK and I think the pumps are rated for 240 degrees max.
 

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Well, I hope impeller parts have nutritional value. :)
 
Now I have 3 spare 007s, two of them brand new, and a new three-speed Grundfos. So I'm really not in the market for any more pumps.
 
The 007 isn't rated for potable water. You need a 006 which has a bronze body and a plastic impeller. The problem is corrosion caused by all the O2 in the fresh water. Oh, and they 'aint cheap like the 007.

Chris
 
That was a plastic impeller. It was the pump I used on my old system to pump DHW between the tank and the coil. That's one tough pump. The whole time I ran it in that house, it was mounted wrong, with the can pointing down. I didn't know any better. It ran like that with no problem for about 6 years. Never had a problem with rust stains in the laundry, and the body is in surprisingly good shape, albeit a bit rusty. I'm thinking the impeller degradation might be cavitation, though I doubt that running it mounted wrong would cause that. Maybe water flashing to steam against the blades at high temps? Debris in the water?

Anyway, I guess the moral of the story is that just because you can hear a pump running doesn't necessarily mean that it's working.
 
high temperature and cavitation would be my guess. Erosion wear is what it looks like to me.

What pressure was the system running under? All centrifugal pumps run better with a bit of pressure on them. Most pumps have a listed NPSH number (net pump suction head).

At 190F you need min um 4 psi inlet side, at 230F 15.6 psi. Temperature makes a huge difference as you can see. This is from the Grundfos submittal data sheet for a similar sized circ.

This is my biggest pet peeve with un-pressurized OWF with high head circs. Assuring that NPSH in many installations is all but impossible.

Throttling down the pump, either on intake or discharge coaxes them to cavitate, also. Plugged y strainers are a big cause, gross mis- sizing also.

What about air removal devices in the system?

hr
 
I agree: I've seen literally hundreds of guys installing the standard 1" pex for all lengths of run and flow rates and then just sticking an 0011 or 0014 on it to try and overcome the head. A year or two later they are wondering why their circ is burned out.

You have to maintain a positive pressure on the suction side of the circ at all times and under any circumstances. Larger bore tubign and lower head circs make that possible. Hydronic piping and pumping is one area where you have to play by the rules. There are no shortcuts.
 
what are the recommendations to prevent this for us guys who like to run the system hot. Whats the best practive to make sure our positive pressure is as good as the specs require?
 
As I said, this was on a domestic hot water line, a 1/2" copper pipe connecting my hot water heater with a coil in a wood-fired boiler. So there should have been plenty of pressure and no excessive load on the pump, from what I can figure.
 
A 007 on a 1/2" short line must have been developing some fairly high velocities (fps) considering at a couple feet of heat it's trying to move around 10GPM. Way in excess of what a 1/2" line will carry, and possibly part of the cavitation problem.. I'm surprised it didn't wear through the copper tube or any ells in the system. A 003 may be a better choice. Or trim the impeller on that 007 :)

hr
 

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Eric, what did you mean by incorrectly having the can down? I think all my pumps have the can down. Is this wrong?
And it sounds like I can't just put a pump anywhere in the loop I wish? Im also one of those guys that just throws some pex in and gusses on the pump size.
 
barnartist said:
Eric, what did you mean by incorrectly having the can down? I think all my pumps have the can down. Is this wrong?
And it sounds like I can't just put a pump anywhere in the loop I wish? Im also one of those guys that just throws some pex in and gusses on the pump size.
Click to expand...
Keep the shaft horizontal and the electricals up. Even before your blowup I was starting to think you were the poster child for how things can go bad. Now you're an absolute winner. Hope your damage was minimal.
 
The can definitely needs to be horizontal, as per the instructions. Otherwise it eats the bearings.
 
"Even before your blowup I was starting to think you were the poster child for how things can go bad. Now you’re an absolute winner. Hope your damage was minimal."

Thanks atlarge54. What exacly qualifies me as a posterchild? My setup was not so bad, I simply made a mistake. You may as well point out anything else thats on your mind.
 
I didn't mean to offend you in any way but it seems like you were having various "issues" all winter. Maybe it wasn't yours but didn't I see pictures of a tar baby EKO and some chimney issues? I just seem to recall lots of your messages this winter. Sometimes a little lighthearted ribbing doesn't translate well over the internet. I'm sure glad I didn't buy a gasser, maybe a pressurized baby garn is what I'm waiting for. If it'll make you feel any better I've got to track down a short in my boiler wiring. I just had a breaker trip the other day and I'm in manual temp control mode now. Can't beat heating with wood-----FREE HEAT----- LOL
 
Your right, I may have overreacted, it may have been the winner line that got me.
Im not sure if Im the tar man, but do have several little issues here or there. I put my system in long before this forum began, and had very little help when I started, so one thing at a time I try to make improvements.
 
Barnartist, Anyone you has installed a gasifier on their own prior to this fantastic forum has my respect!

Don
 
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