Circulator pump: How to store a used pump for re-use

[atlarge54]

I run my boiler (really it's lge. mass based heat exchanger) in the summer to run a sidearm DHW system. In the winter I run a 011 circ pump, in the summer I like to isolate all the heat runs and step down to a 007 pump. When I pull a circ out of service what should I do to prepare it for storage? Normally I spray WD40 or some type of aerosol lube into impeller area and run the pump briefly on the bench. They always (the 007s) seem to need some extra work when it's time to re-start.

 

[BrownianHeatingTech]

I run my boiler (really it's lge. mass based heat exchanger) in the summer to run a sidearm DHW system. In the winter I run a 011 circ pump, in the summer I like to isolate all the heat runs and step down to a 007 pump. When I pull a circ out of service what should I do to prepare it for storage? Normally I spray WD40 or some type of aerosol lube into impeller area and run the pump briefly on the bench. They always (the 007s) seem to need some extra work when it's time to re-start.

Keep it wet in the system, and use tees and valves to put the two circulators in parallel.

Then periodically switch the non-used one on for a few seconds every week or two. You can get an electronic device to do that, or just use a switch.

Letting them dry out during the summer is not good for them. If you run it for a few seconds each week or two, it will knock loose any deposits.

Joe

 

[Redox]

I think some boilers have an "excercise" cycle in their programming to do just this. It didn't used to be a problem before the canned rotor pumps came out. Then again, we don'y have to worry about couplings and seals any more...

Chris

 

[Bob Rohr]

Do you really need the 0011? Could it be a bit more circ than you need? Consider a 3 speed circ that could cover more range for you. A Grundfos 15-58 may be enough power for you. Or the next step up 26-99 3 speed. Then the issue of switching circs goes away

The Grundos circs have an electronic "tickler' that helps prevent any stuck rotor issues.

While the 0011 may consume more power, it may get the job done in 1/2 the time. Maybe you don't need a second circ? Unless you have noise and velocity issues.

Wait a few months and you can buy an ECM circ and use 40% less power to get the job done. With a delta P function it will adjust to the system's changing loads.

hr

 

[atlarge54]

Do you really need the 0011? Could it be a bit more circ than you need? Consider a 3 speed circ that could cover more range for you. A Grundfos 15-58 may be enough power for you. Or the next step up 26-99 3 speed. Then the issue of switching circs goes away

The Grundos circs have an electronic "tickler' that helps prevent any stuck rotor issues.

While the 0011 may consume more power, it may get the job done in 1/2 the time. Maybe you don't need a second circ? Unless you have noise and velocity issues.

Wait a few months and you can buy an ECM circ and use 40% less power to get the job done. With a delta P function it will adjust to the system's changing loads.

hr

The reason I had to go to a bigger pump was to get the system bled out. I've got five 60' coils of 3/4" copper wrapped around an old OWB firebox. They connect to a 1" rigid copper manifold at the top. The smaller pumps just couldn't get all the air out and when the fire got really hot I think I could hear a little steam flashing in the tubing. It sounded almost like a mouse running around inside and only happened when really hot. The pump fixed it . Does Grundfos have vol./head charts on their website? I think now I could drop back to a smaller pump.

 

[Bob Rohr]

yeah, the pumps job really isn't to purge air

But I know what you mean about purging multiple loops like that, without individual shut offs to isolate, it can be a hassle.

Some of my geo installing friends have built purge carts with old swimming pool pumps to blast all their ground loops clear. Nothing like mucho gpm to get the job done. Large snowmelts can pose the same problem if iso valves were not included at the manifolds.

Once the air is out, keep it out, and a small circ should easily move the flow you need.

hr

 

[BrownianHeatingTech]

I've got five 60' coils of 3/4" copper wrapped around an old OWB firebox. They connect to a 1" rigid copper manifold at the top. The smaller pumps just couldn't get all the air out and when the fire got really hot I think I could hear a little steam flashing in the tubing. It sounded almost like a mouse running around inside and only happened when really hot. The pump fixed it . Does Grundfos have vol./head charts on their website? I think now I could drop back to a smaller pump.

If you are flashing water to steam in that setup, then you definitely do need to maintain the flow (at least, under the fire conditions that cause the steam problem, since it sounded like an occasional thing in your post).

The Grundfos pump curves for the SuperBrute pumps (the three 3-speed pumps that are the majority of the residential product line) are here: http://www.grundfos.com/web/HomeUs.nsf/GrafikOpslag/superbrute/$File/UPSpecpages.pdf

Joe

 

[atlarge54]

Thanks for the link Brownie. If I ever need to replace a pump I'll probably go with a multi-speed unit. I keep a couple big marine batteries and an inverter handy in case of a power outage. There's enough thermal mass to give me a good margin of safety plus all internal joints are phos-brazed. The flashing was very very minimal but made me very very nervous. It sure is nice to have you pros share your knowledge.

 

[BrownianHeatingTech]

Thanks for the link Brownie. If I ever need to replace a pump I'll probably go with a multi-speed unit. I keep a couple big marine batteries and an inverter handy in case of a power outage. There's enough thermal mass to give me a good margin of safety plus all internal joints are phos-brazed. The flashing was very very minimal but made me very very nervous. It sure is nice to have you pros share your knowledge.

If you only need the 15-58, they're pretty cheap. Granted, it doesn't flow as much as a 0011, but it does flow more than a 007. If the steam issue is minimal, then the extra flow might be enough.

Might be something to take care of this fall, instead of putting the 0011 back in...

Joe

 

[Bob Rohr]

Loops wrapped around a cylinder like that will be prone to air bubbles at the top of those "rungs" as the water heats and air is driven out of solution it will work it's way up to those high points, every time the circ is off for a period of time. Without flow in any of the loops you risk the flashing you are experiencing.

If it could be installed with the headers up at the high point you could install small auto air vents to eliminate that problem, also.

Maybe a constant circulation arrangement would be better. It's a common fix for Clean Burn waste oil boilers that have a coiled HX like that.

hr