Taco 0015-MSF2-IFC 'Rattling' Sound

JustinS

For a while now, one of my Taco 0015 circulators has been making a sort of rattling/crackling sound. I can hear this standing in front of the unit as well as in the zone itself due to the sound translating through the piping.

I could replace it with the same model but I have concerns that it may not be the right size for the zone in question. All three zones are using the same model with each operating at Low speed and are as follows:

1st floor - ~39 ft plus kickspace heater => ~26600 BTU/hr
Master BD - ~25 ft for ~45% of upstairs => ~14500 BTU/hr
2nd floor balance - ~25ft for ~55% of upstairs => ~14500 BTU/hr

I can hear the water flow in the Master BD (smallest zone) whenever it's on. Furthermore, there is negligible delta-T across the system (all 3 zones yesterday only had 6F drop).

I wonder if this means that my flow rate is too high and if a different circulator would be better suited?

Thoughts? Thanks in advance!

HomerJSmith

Ya! No delta T certainly indicates a high flow. Too high a flow based upon the pipe sizing can erode the piping and create noise. A Taco 0015 is a high head pump even on low speed. Set your speed to the lowest setting and see what happens.

Jamie Hall

At the flow rates you seem to have, I'm bettiog that the pump is cavitating. Turn the speed down if you can, or restrict the flow with a throttling valve and see if it goes away. Hopefully the pump is still OK

hot_rod

does it have a check valve installed in the volute? Sometimes that can rattle.

Mustangman

Yeah, hope your pump weathered the storm. Jamie may be right. Can I asked who recommended the 0015? They are large high head pumps that you probably don't need. The noise can be from a few things. Are the pumps IFC if not do you have flow checks? The internal flow checks are kind of cheesy and could be giving you the noisey sound. With the pumps being over sized, when you get a call for heat on one zone, possibly the flow check on a nearby zone is opening? Easy way to check is shut off one of the return valves and see if the noise stops or changes.
Steve

JustinS

The pumps have an internal IFC and there are inlet/outlet isolation valves.

Not sure who recommended it, they were installed when the house was built (2013). Unfortunately, I think that there wasn't much in the way of proper sizing calculations done, yielding more to a "bigger is better / rule of thumb" approach.

Jamie Hall said:

At the flow rates you seem to have, I'm bettiog that the pump is cavitating. Turn the speed down if you can, or restrict the flow with a throttling valve and see if it goes away. Hopefully the pump is still OK

Unfortunately, speed is turned down as low as possible (all three are set to Low vs Med/High). There are isolation ball valves and/or return ball valves, could I partially close off one of those to reduce the flow per your suggestion?

Big Ed_4

You think you hear water , but your hearing air ...

The chatter in the pump , try a different speed..

pedmec

its most likely the check valve that's rattling. change out that circulator before it erodes your baseboard and you start pitting. the high velocity water racing thru the pipes is gonna thin out already thin baseboard.

JustinS

Big Ed_4 said:

You think you hear water , but your hearing air ...

The chatter in the pump , try a different speed..

But it's only in that single zone - if it was air moving through the pipes, wouldn't I hear it in other zones too?

Already at the lowest speed, trying faster speeds makes it more noticeable.

pedmec said:

its most likely the check valve that's rattling. change out that circulator before it erodes your baseboard and you start pitting. the high velocity water racing thru the pipes is gonna thin out already thin baseboard.

What should I change the circulator out to? What model/manufacturer? That's the thing that I am most unsure of.

hot_rod

What type of boiler, what size, how is it piped, send a pic.

Some of the direct piped mod cons required a high head circ due to the pressure drop through the boiler. Same with tankless water heaters masquerading as a boiler.

JustinS

It's a Triangle Tube Prestige Solo 110, 3 zones plus TT SMART80 DHW tank as 4th zone.

hot_rod

Is this a footage of fin tube baseboard?

If so,
first floor fin tube + kick space heater about 3.2 gpm
Master loop 1.4 gpm
Second floor 1.4 gpm
6 gpm total flow required

This calculation is based on a 20∆, 10,000 btu per gpm

Even the smallest pump on this curve chart is oversized, I assume that is a 007?

You need something like a 003 or 006

Classic case of where zone circs might not be the best choice when the load is 6 gpm, smallest zone 1.4 gpm.

A single circ and zone valves would be a better option. A 007E perhaps.

JustinS

hot_rod said:

Is this a footage of fin tube baseboard?

If so,
first floor fin tube + kick space heater about 3.2 gpm
Master loop 1.4 gpm
Second floor 1.4 gpm
6 gpm total flow required

This calculation is based on a 20∆, 10,000 btu per gpm

Even the smallest pump on this curve chart is oversized, I assume that is a 007?

You need something like a 003 or 006

Classic case of where zone circs might not be the best choice when the load is 6 gpm, smallest zone 1.4 gpm.

A single circ and zone valves would be a better option. A 007E perhaps.

Yes, the lengths I provide earlier are the measured baseboard lengths.

Converting the system to zone valves is likely more $$$ than I'd like.

I am wondering if perhaps replacing the 0015 existing with a 0015e model would work. The brochure seems to indicate that its LOW performance matches up with the 006? It also seems like it'd be easier to swap the 0015e out instead of the 006 as its flange interface seems same as 0015 existing.

It also seems to be reasonably priced.

I think that I have to settle for a good guess since I can't really determine the head required as I don't really know the piping paths, right?

hot_rod

you could use one of the pumps you have, 3 zone valves and a pressure bypass valve, that would be the least expensive correction. And you have two spare circs

JustinS

hot_rod said:

you could use one of the pumps you have, 3 zone valves and a pressure bypass valve, that would be the least expensive correction. And you have two spare circs

Wouldn't I have to replace the zone board (SR504) since it's got 120VAC outputs and the zone valves are 24V?

My preference is to keep this as simple as possible (i.e, swap out identically sized circulator) so I don't have to involve my HVAC company. The reason being that replacing my DHW 0015 last year was ~$800.

Big Ed_4

Is the circulator that is chattering on the same zone that you hear the water flow ? If so , there is air in the line.. Does the zone piping run under a slab ? Your circulator , is it installed on the return or supply ?

JustinS

Big Ed_4 said:

Is the circulator that is chattering on the same zone that you hear the water flow ? If so , there is air in the line.. Does the zone piping run under a slab ? Your circulator , is it installed on the return or supply ?

Yes, the chattering is on the zone where I hear the water flow.

There is no slab in the house. The circulator is on the supply.

hot_rod

JustinS said:

hot_rod said:

you could use one of the pumps you have, 3 zone valves and a pressure bypass valve, that would be the least expensive correction. And you have two spare circs

Wouldn't I have to replace the zone board (SR504) since it's got 120VAC outputs and the zone valves are 24V?

My preference is to keep this as simple as possible (i.e, swap out identically sized circulator) so I don't have to involve my HVAC company. The reason being that replacing my DHW 0015 last year was ~$800.

Well replacing the 0015 with the electronic 0015E is probably going to cost around 800 bucks,or so
just looking at online pricing.

To go with zone valves would involve 3 valves a pressure bypass and a zone control box, probably in the 500 dollar range using online prices. With some labor involved to switch pumps to valves.

Can you get the contractor back that oversized those circulators?

JustinS

hot_rod said:

JustinS said:

hot_rod said:

you could use one of the pumps you have, 3 zone valves and a pressure bypass valve, that would be the least expensive correction. And you have two spare circs

Wouldn't I have to replace the zone board (SR504) since it's got 120VAC outputs and the zone valves are 24V?

My preference is to keep this as simple as possible (i.e, swap out identically sized circulator) so I don't have to involve my HVAC company. The reason being that replacing my DHW 0015 last year was ~$800.

Well replacing the 0015 with the electronic 0015E is probably going to cost around 800 bucks,or so
just looking at online pricing.

To go with zone valves would involve 3 valves a pressure bypass and a zone control box, probably in the 500 dollar range using online prices. With some labor involved to switch pumps to valves.

Can you get the contractor back that oversized those circulators?

No way that I can get that contractor back - he's a jerk and has outright told me that he did nothing wrong and that i don't know what I'm talking about.

Maybe we're talking about two different things but the 0015e3 seems to be ~$220 on SupplyHouse?

https://supplyhouse.com/Taco-0015E3-2F4-0015E3-ECM-High-Efficiency-Wet-Rotor-Circulator-Pump-w-ECM-Permanent-Magnet-Motor

I also noticed the 006e which appears to be fully variable where I can adjust it to be really low head. Only thing is that it doesn't have the same flange setup as the 0015. Looks like just standard hose threading.

https://www.nationalpumpsupply.com/content/pdf/006e-taco-ecm-high-efficiency-circulator-pump-brochure.pdf

****EDIT****

Actually, I think that the Taco VR1816 is the one I'd want for a fully variable circulator, as opposed to the 006e.

hot_rod

All the small fixed speed circs in the capacity you need are for DHW recirculation, so they are bronze or stainless, mostly union or sweat. There are some flanged stainless, but $$.

I think any electronic circ will be in the 200 plus $$ range.
Pick a brand or model, even on the lowest settings you may still be over-pumping. But in a better place than you are now with the 0015. And with ecm, you will be saving pumping power.
Four circs to do such a small load just strikes me as over-kill.

As far as the head loss of the circuit, here is an example of how to come up with that number. If you could see all the piping and fittings. For this example of 100'EL, the pressure drop is 4.93'. I suspect you are in the same ballpark?

JustinS

hot_rod said:

All the small fixed speed circs in the capacity you need are for DHW recirculation, so they are bronze or stainless, mostly union or sweat. There are some flanged stainless, but $$.

I think any electronic circ will be in the 200 plus $$ range.
Pick a brand or model, even on the lowest settings you may still be over-pumping. But in a better place than you are now with the 0015. And with ecm, you will be saving pumping power.
Four circs to do such a small load just strikes me as over-kill.

As far as the head loss of the circuit, here is an example of how to come up with that number. If you could see all the piping and fittings. For this example of 100'EL, the pressure drop is 4.93'. I suspect you are in the same ballpark?

Hi Bob

So that I can better understand, could you elaborate on how the pressure drop was calculated @ 4.93'?

Was it using this equation?

hot_rod

Here is a formula and the Idronics issue that takes you step by step through pump sizing.

https://www.caleffi.com/sites/default/files/media/external-file/Idronics_16_NA_Circulation in hydronic systems.pdf

Years ago I saw an interesting pump offering from Wilo. These micro pumps were intended for small gpm loads used at the heat emitter or on a manifold. They tied to a control that could modulate them based on various conditions, ODR for example.

Dave H_2

@JustinS The 0015e3 on low does operate lower than the 0015.

The VR1816 or the 0018e gives you the option to dial in the circ to the flow and head you want/need.

The VR1816 has the dial and 0018e has the same dial but it also has a bluetooth app so that you can "see" the flow and head and dial it in even better.

As for the rattling you are hearing, it could be the check valve as others have mentioned. You have isolation flanges, pop out the offending circ and replace the check valve. That is the easiest and least expensive fix.
A 6 degree temp drop in April is not that bad for your system running on low speed. A 20 degree is expected for the really cold days in the heart of the winter, so running on low for your 0015 is as great as it can be.

hot_rod

I'd guess most of the pump brands have similar features now.

I have my Alpha 15-58 cranked down to 2.3 gpm, 5W power, on the app. In zone pump mode.

With a balance valve I could get to the 1.4 gpm, 4w, 2161 rpm
All controlled from the Grundfos GO app on my i-phone.

I don't see a big concern if you pump 2.3 gpm in those small loops. More heat output and you are still well within the acceptable velocity for 3/4 copper.

JustinS

Dave H_2 said:

@JustinS The 0015e3 on low does operate lower than the 0015.

The VR1816 or the 0018e gives you the option to dial in the circ to the flow and head you want/need.

The VR1816 has the dial and 0018e has the same dial but it also has a bluetooth app so that you can "see" the flow and head and dial it in even better.

As for the rattling you are hearing, it could be the check valve as others have mentioned. You have isolation flanges, pop out the offending circ and replace the check valve. That is the easiest and least expensive fix.
A 6 degree temp drop in April is not that bad for your system running on low speed. A 20 degree is expected for the really cold days in the heart of the winter, so running on low for your 0015 is as great as it can be.

@Dave H_2, thanks for that info - the 0018e seems nice. Good point about it being April, although I don't recall ever seeing any significant delta-T even when it's been really cold.

hot_rod said:

I don't see a big concern if you pump 2.3 gpm in those small loops. More heat output and you are still well within the acceptable velocity for 3/4 copper.

@hot_rod Thank you for those screenshots and very much for the Caleffi article and formulas!

My plan now is to

1) try purging air once the heating season is done
2) Replace check valve if 1) doesn't work
3) Replace circulator if all else fails

Thank you all for your input.

hot_rod

Listen for a hissing sound in the fin tube or piping. That is an indication of excessive velocity. It can cause excessive wear in the components, besides being annoying. You could use the iso flang valve on the pump discharge and force that desired gpm. You'd be running with the accelerator floored and the brakes as your speed control. Possibly induce a cavitation issue. Which is what you may be hearing anyways, with that pump trying to move 10- 12 gpm in 3/4 tube..

Stay below 5 fps in hot water, constant circulating hydronics.
This chart below shows velocity at various flow rates. 7 gpm in 3/4 type M would be 4.3 fps.

When you observe delta T on an operating system it really depends on where the system is in it's run cycle. When you first call for heat, emitters at 68F, SWT, supply water temperature ramping up, expect to see a wide delta, even perhaps beyond what you designed for.

Thermal equilibrium happens when the SWT and RWT are no longer changing or moving. If you want to sit and wait to observe that condition. The heat emitter is always in charge of the operating condition. Unless you invoke controls to prevent that.

As the emitter warms and ambient warms the delta will close, maybe to a few degrees just before that zone satisfies. ∆ goes to zero when the circulator stops, so heat being delivered also stops.

So think of that ∆T reading as an indication of heat being transfered at that exact point in time. Put into a formula with a known flow rate gives you the BTU/ hr being delivered.
500 X flow X ∆.

The delta is a bit of a moving number based on the load at any given point. Some systems may never run at the designed for ∆. Yours for example With the over pumping we suspect

An operating ∆ for a design is a number pulled out of thin air. Some radiant designs use 10- 15 for residential radiant. Commercial radiant shops may run a 30∆.
Panel rads 30- 35∆.
I could use 33.75 as my design ∆. Its a number you size stuff to: pipes, pumps, heat emitters, nothing more.

More on heat transfer here.
https://www.caleffi.com/sites/default/files/media/external-file/Idronics_23_NA_Heat transfer in hydronic systems.pdf

JustinS

hot_rod said:

Listen for a hissing sound in the fin tube or piping. That is an indication of excessive velocity. It can cause excessive wear in the components, besides being annoying. You could use the iso flang valve on the pump discharge and force that desired gpm. You'd be running with the accelerator floored and the brakes as your speed control. Possibly induce a cavitation issue. Which is what you may be hearing anyways, with that pump trying to move 10- 12 gpm in 3/4 tube..

I definitely hear a sound other than the "rattling" when standing in the zone. I don't really know how to describe but maybe it could be considered a hissing sound? It definitely doesn't sound like water sloshing or gurgling.

Thanks again!

hot_rod

I guess hissing is the best way to describe high velocity flow. You sometimes hear it in plumbing piping when a hose bib is flow a high gpm rate.

Gaseous cavitation first sounds like a popping noise, almost like a loud bowl of Rice Krispies. As things get worse, vaporous cavitation sounds like stones or gravel being circulated. That is when the destruction starts.

It is somewhat dependent on the fluid temperature, so if the noise occurs only at higher temperatures?

Increasing static fill pressure, lowering operating temperature can help eliminate cavitation. Elevating the fill pressure can also help stubborn air removal.

Ever check the air purger screen? A restriction there will not be kind to high head circs either.

JustinS

hot_rod said:

I guess hissing is the best way to describe high velocity flow. You sometimes hear it in plumbing piping when a hose bib is flow a high gpm rate.

Ever check the air purger screen? A restriction there will not be kind to high head circs either.

I've never opened that up, I do have annual service whom I have relied upon for this sort of thing. Although, I wouldn't be surprised to learn that they may not check this sort of thing?

JustinS

So here's some video of the sound, both in the zone (1st) and down in the basement (2nd)

Joe Mattiello

That’s a good looking system. Dave H, nice call on simply replacing check if needed, but more likely air. What’s the system pressure, try increasing pressure a bit to help squeeze the air out. If there’s air vents at the top of the system, and your pressure drops, those vents can be under vacuum. 

If you continue to have issues, or concerns, call Taco Tech support at 401-942-8000. 

The good news, you inherited great pumps!