Noisy Taco 007?

Jells

I have a 007 that was a little rattley sounding, so I swapped out the cartridge, but there's been no change! Anything to be done, can it be the check valve in there? Not the end of the world, but it's in the tenant's living room.

newagedawn

is there already a check valve in the loop?

HVACNUT

Could be air. Air eliminator working?
Try purging the loop.

Jells

There's 2 check valves in the loop, and the Taco is mounted vertically so no air should be trapped. If there were enough air to reach it, it would be full of air and not function.

HomerJSmith

Are you sure that you don't have a swing check valve some where that's rattling? You can use a mechanic's stethoscope to try and pin point the source of the noise. Has it always been this way, if not when did it start and what did you do to the system prior to the noise?

Jells

Homer, It's rental so I don't know when it started, I noticed it showing it to new tenant prospects. Definitely no swing valves, both checks are spring type. I guess I could try a stethoscope, but it seems pretty clear it's coming from the pump.

I took this video for the sound, pumps definitely working, place is warm.
https://youtu.be/wV3_w5V7PW4

HomerJSmith

Wow. Interesting sound, a rattling for sure. This is my thought--the IFC is out of the volute housing and is rattling against the ell on the output of the pump.

"Hot Rod" had an experience where that happened to him. The IFC came apart and lodged in the boiler HX an created intermittent problem, so it does happen.

You can put the tip of a mechanic's stethoscope on the ell and you would certainly know for sure or move the tip to where the sound is the loudest. That should help in finding the problem.

HomerJSmith

You know that a pump should be mounted with 12 pipe diameters of straight pipe on the inlet and at least 5 pipe diameters of straight pipe on the outlet before any change of direction.

Jells

Thanks Homer. No I didn't know that spec, but this one was actually installed by pros not DIY! It's amazing the faith some people have that pros will get everything right. My current guy doesn't believe in setting water heaters to high and using a mixing valve.

Speaking of water heaters, that's what this pump is on, so there's not much complication there. Maybe I should try and pull the IFC and see if that makes a difference.

HomerJSmith

Hold your horses! You are telling me that the 007 is on a water heater. Is it an indirect water storage tank connected to a boiler or is it a gas fired or electric water heater? Is the 007 a re-circulation pump? What does the 007 do? What is the 007's purpose?

If the 007 is connecting a boiler to an indirect water storage tank you will need a check valve on that circuit and if the 007 is a re-circulation pump, you will also need that check valve. The 007 is really much too large a pump for a re-circulation pump.

You need to be more forthright with your information.

Jells

Sorry, I didn't see the relevance to the pump rattle. It's on a 40 gal B-W gas natural vented water heater rated for room heating, and heating a 450 ft apt attached on both side. Does a terrific job and has been in place since 2003 with one WH replacement.

HomerJSmith

The 007 is brown, so that indicates that it has a bronze volute which is used on an open system like on a gas fired or electric water heater. Pictures of your system would help.

Jells

Yes, it's a bronze pump, because it's a "potable water" system. The
legionella risk downside to this setup has been explained, and I plan to update these to heat exchanger based systems.

HomerJSmith

So, your water heater is providing domestic hot water and space heating? What is the water temperature coming out of the W/H?

If you are familiar with legionella bacteria, you know the incubation temperatures and the kill time for various temperatures. I believe in a heat exchanger between the space heating and domestic hot water as the space heating is a dead leg in the summer time when it isn't running, but it involves added components like an expansion tank and pump. But you still have the legionella potential problem in the domestic side.

Jells

Yes DHW & heat, tank set to Max, measured 138 the other day on another unit.

My impression was that a proper system needed the tank side circulator running year-round for safety even when the loop side circulator is off.

HomerJSmith

There is a scald potential with water at 138 deg, which can be a liability to a landlord should scalding occur. At those temperatures, point of use thermostatic tempering valve should be used where ever hot water comes in contact with people.

Jells

I believe I mentioned including the mixing valve upthread! I have them everywhere. Had an argument with my current plumber who didn't think it necessary to set a 75 gal serving 4 units to hottest and use a mixer.

Zman

Are you sure the noise is coming from the circ. It sure sounds like a mixing valve noise.

Jells

Zman said:

Are you sure the noise is coming from the circ. It sure sounds like a mixing valve noise.

The mixing valve is not in play when there's no water running, this is just the zone circulating.