Prestige/Wilo

Derheatmeister

I "fixed" it by relocating the expansion tank to the return side, do you think that the Pump gets "Confused" when you pump towards the Expansion tank ? does it ramp up the speed to see a "Pressure/ resistance increase" just to have a Jojo effect/ knocking?

Derheatmeister

Prestige/Wilo Combo

Hoppy new year to all on the wall..

A couple months have passed since i "Married" a TT prestige and a Wilo Stratos ECO and all was fine until the other day: the costumer was complaining about a noise that sounds like someone Rapping on the door!

About the System: I removed the Boiler circ and replaced it for a Wilo and piped the old baseboard system(Over sized Baseboards) directly to the boiler, all preexisting Zonevalves where left..

The only thing i can see wrong which may have cause the "Knocking" is that the system was setup to "pump" into the Expansion tank.

Today i hooked up a expansion tank on the return side of the Boiler and the "Knocking" noise almost disappeared.

Has anybody also seen the "Knocking" noises on the Wilo Ecos in a Pumping into the expansion tank situation??

I think it has something to do with the "Smarts" of the circ..!? Richard

Mark Hunt_6

Hi Richard

Could you e-mail me the specifics of this install?

Off the cuff guess here, but pumping toward the PONPC might have an effect on the rpm of the Stratos or Eco. The "knocking" sounds more like insufficient flow across the HX.

Mark H

Mark Hunt_6

Well


The Stratos and the Eco will slow down as zones close. If the circ is pumping toward the expansion tank it would not "see" any change and not modulate up or down. It would just find a "happy place" and stay there with regard to flow. Once the boiler kicks up its firing rate that GPM may not be enough through the HX.

If you are still getting the knocking noise, even if it is slight, you may want to bump your head set point up a bit. This will give you higher GPM at the lower end of the circ's performance incline.

Hope this helps!

Mark H

DanHolohan

It wouldn't see it on its discharge side,

but it should see it on its suction side, yes? Is the Stratos and Eco able to pick up that? If it's sensing delta-P it should be able to do that, yes?

Mark Hunt_6

Not really


There are no sensors in the circulators other than thermistors so the circulators are not calculating pressure differential.

What the circs "see" is resistance or the lack of resistance in the system based on the RPM of the rotor in relation to the stator field. As more zones open there is less resistance, the impeller speeds up and the stator is adjusted accordingly. As zones close the impeller RPM is effected due to more resistance and the stator is adjusted.

But if the circulator "sees" a constant head, it may not adjust. I say "may" because to be honest with you, I have not experimented with this yet.

What Richard describes though is what I have suspected would happen if a Stratos or ECO were put upstream of an expansion tank. Without actually being there and monitoring the circulator in real time, I am just guessing at this point.

Someone should write a book about "Pumping Away".

Mark H

DanHolohan

Is this something

you could test on the Brain Box?

Mark Hunt_6

Yep


I can change the PONPC to the head side of the circulators.

I am heading to Maryland next week and I will do just that. I do not keep the Brain Box set up in my house. One car garage and the wife has laid claim to that space. I dare NOT argue.

I'll let you know what I find.

Mark H

DanHolohan

Thanks.

I figured you have the Brain Box in your kitchen. Give it a try. She'll come around. :-)

NRTDave

Battling Contrrollers

I'd be worried about the MCBA getting confused by the changing flows of the water. I think the MCBA possibly could control a VS circ with PWM using parameter 37.

What kind of ΔT does the boiler have when it is knocking?

Derheatmeister

Delta T is next to none,boiler has not even fired yet! only on circulating only.

Tony_23

MCBA

TT locks out quite a few of the parameters that others may use in the MCBA.

My only complaint with the operation of the Prestige is the inability to fine tune it.

Unknown

A different view

First, hey Mark, that Brain Box has wheels. I thought you had motorised it and sold the company van...

Regarding the niose, I suspect it's the HW boiler steaming. An old, probably waaay oversized pump probably had enough head to compensate for the wrong tank location. Installing a "smart" pump that will provide only enough head to properly overcome friction loss likely did not have enough head to make up for the tank location problem.

If you are flying the wrong direction, into the wind (pumping into the expansion tank) with a plane with a real big engine at a constant high RPM using a lot of fuel and replace it with a properly sized engine but do not correct the flight direction the plane might crash.

Mark, your test results with the Brain Box will be interesting - let us know.

Derheatmeister

NO DELTA T !!

No Heat is on in this Equation

OR the Boiler has not fired Yet when this noise is occurring!!

SO that tells me that it is Flow conditions..??

I will go back to this install next week to Experiment or Figure out what has changed and let Yuall know what i found..

Richard..

Unknown

Is it possible as most of the head the Stratos was building was absorbed by the expansion tank when in the wrong location, that the noise was a chattering gate valve?

Just guessing...

Derheatmeister

Chattering

Yes maybe, I will recheck the Pressure on the expansion Tank as well, No "Gate valves" but Swing checks on the Return !

scott markle_2

Minimum flow- off topic tangent

I like the simplicity and potential efficiency advantages of a direct connected mod-con. Constant head pumping seems a very useful innovation for zone valve systems that have ever changing pumping requirements.

Multi zone variable speed pumped (direct connected) mod-cons are an interesting and viable option (for some boilers). But if not carefully considered, this arrangement does pose the risk of insufficient flow through the boiler. ie.- a flow restrictive zone running solo. This possibility is heightened by the use of a smart pump, which in maintaining constant head may not achieve the min. flow required by the boiler. A conventional pump would probably just over pump this solo zone, wasting energy and lowering the delta but maintaining required flow through the boiler. A smart pump with a head pressure set too low could get in trouble in this situation. Wilo should consider putting some sort of tamper guard (locking cap) on the head pressure adjustment, for systems where a specific head is required for safe operation.

It could be could be argued that "intelligence"(extra electronics) may add some risk of malfunction, perhaps it is prudent to avoid installations (non P/S) where a failure (or even tampering) could adversely impact other components.

It would be reassuring to know that if the feedback mechanisms of the pump ever failed the pump would revert to a full throttle unregulated "fail-safe" mode of operation or stop entirely.

Tony_23

Not really

All you'd have to do is program for the head of the boiler plus the shortest zone as a minimum. The head loss of the boiler is usually printed in the I&OM.

I could be wrong....

Tony_23

My questions

Why hasn't this boiler been fired yet ? Why is the circ running w/o fire ? Is there another source of heat in the system ?

scott markle_2

Wouldn't that be the longest zone Tony?

Tony_23

Well,

That would be maximum head.

If minimum is a function of maximum, and maximum is the only one settable, you're right. If minimum is settable as well, my statement is correct.

In an earlier post, Mark states that Richard may need to bump up the max head setting, and in so doing will increase minimum flow. I'm sure Mark will come back and answer

scott markle_2

The dial on the eco represents actual head (as long as the pump can keep up.) I'm not sure what the operating deviation from this setting is, but I think it's fairly tight. I's as much a min setting as a max setting if the pump is sized correctly.

My concern is this-

Let's say 7 ft of head will move 2.5 GPM (hypothetical boiler min) through the most flow restrictive zone in the system. This is fine,richard has probably measured the footages and fittings and has a math based estimate of what this required head is, he knows that a lower setting will give higher deltas and better efficiency but going too low could mean not enough flow to satisfy the boiler min.

What happens if some missguided simpleton in the future turns the dial down on the circulator? Also could the "brain" misinterpret it's feedback and deliver less than dialed in setting?, creating a failure path that wouldn't exist with a fixed speed circulator?

Finding a potential flaw with Richard's work is good natured harassment.I'm looking forward to commissioning an eco shortly in a multi zone killer radiant application.

Tony_23

Scott

I'd say your concerns are valid regarding minimum flow through the boiler.

I wouldn't want to be the guy responsible for a meltdown not covered by warranty because the I&OM didn't address it or the mfg didn't approve it.

Derheatmeister

LOOSE PIPE'S

Just found the "Problem" with the TT/Wilo combo :Someone was using the pipes in the basement to hang the clothes on and broke the "Mickey's", Pipes are loose and banging around and all that is needed is re securing...

That was to easy that we overlooked it.

All is well in the high county
Richard

Mark Hunt_6

Good deal


Could you please e-mail me some pics?

I would appreciate it Richard.

Thanks!!

Mark H

scott markle_2

Pictures

Mark,

Here are some pictures of the job I spoke to you about. Just commisioned it yesterday, the spray foam helper put a staple thru my pipes in two locations, I guess radiant tubing is unfamiliar to hard working immigrants from Mexico.

I'm heading south my self for a much needed break in sunny costa rica. Glycoled up the system, just in case. Thanks to everyone here who has helped so much in realy learning the nuances of this trade. Also thanks to the manufactures who's products made this all possible- Triangle tube, Viessmann, Callefi, Danfoss, Viega, Istek, Uponor, Tekmar, Roth and probably a few more.

Brad White_203

Outstanding work, Scott!

Excellent craftsmanship and attention to detail. Wish it were my house...

What was the foam used? That green stuff, I forget the brand. Looks nice and snug. Where is it located?

Derheatmeister

Clean

Nice clean and thought out work,

I like the PIG too.

Mark Hunt_6

SWEEET!


Awesome work Scott!

Mark H