2 month old B&G NRF-22 squeal/screech/chirp noise

baggs32

<strong>Hi there, new poster here.  I can't believe I didn't find this site before!  Anyway, I replaced a B&G 100 series circulator with a new B&G NRF-22 circulator about two months ago.  All was well until Thanksgiving night when we returned home to an alarming noise coming from the radiator pipes that sounds like a smoke alarm for lack of a better description.  It's a high pitched squeal/screech/chirping noise that only appears during some heating cycles and only when the temp of the boiler is between 140F and 150F.  The boiler is an older Burnham gas fired unit that only feeds 6 radiators on the first floor of our 1.5 story Cape Cod.  The PSI is about 9 or 10 cold and about 10 or 11 hot and it rarely goes above 145F per cycle.  </strong>

<strong>I replaced the 100 because it was leaking and I didn't want to deal with oiling it anymore.  All I did was drain the entire system, unbolt the old 100, bolt the new NRF-22 on, and refill the system.  It worked great for almost exactly 2 months but now it's noisy sometimes.  All that I've read so far points to failing bearings in my new pump or possibly air in the system.  I've bled for air so I'm hopefully ruling that out.   </strong>

<strong>Does anyone have any suggestions for a remedy?  I have no problem replacing the pump but I fear that may not be the best solution given how new the one is on there now.  If replacing it is the way to go is the NRF-22 the one to still use or is there another make/model that would fit the B&G flanges and be more reliable?</strong>

<strong>Any help is greatly appreciated.</strong>

<strong>Thanks!</strong>

baggs32

More info on the noise

In addition to my original post I just had the opportunity to listen to the circulator on start-up.  It was completely silent at first but after about 5 minutes a slight, soft ringing noise could be heard coming from inside the unit but you have to have your ear right next to it to hear it as it is not heard through the pipes.  It appears the sound is there but just gets amplified as it gets hotter until it is ringing through the pipes.  It's a steady noise for about a minute at a time at temp but cuts off here and there and sometimes chirps when it first starts. 

It has to be the pump bearings right? 

Ironman

It's the Pump

I've had NRF -22 pumps do the same right out of the box. B&G has always had some of, if not, the best hydronic components around. But their wet rotor pumps like this one are now made in china. Need I say more?



I'd recommend a Taco 007 or a Grundfos UPS15-58. Either one will connect to your flanges. However, I'd recommend that you install isolation flanges while you've got the system drained. That way you won't have to drain it to change the pump ever again.



Also, you need 12 psi minimum on a cold boiler for a two story house and 18 psi minmum for a three story. Try adjusting your fill valve by loosening the lock nut on the stem and then slowly turning the stem clockwise until the pressure increase to where it should be.

baggs32

Had to be the pump

Thanks Ironman!  All things led to a bad pump so thank you very much for confirming it.  I wish it were easy to install stop valves for the pump but the original installer apparently did not have that in mind.  The lower flange is attached directly to the drain pipe so there is no room for a valve down there unfortunately.  I could modify it to fit but I'm just not that experienced so draining is my best bet. 

I may go with the Taco as it is a little cheaper and is highly rated it seems.  Thanks again for the advice and I guess I'll be installing my new circulator within the next week or so depending on when I can get one. 

Charlie from wmass

Start by saying I prefer Taco pumps

But I must say 5 years ago I did have a 007 that had a bad casting and made noise when it ran. Of course the wholesaler gave me a new one and sent the old one to Taco. they replaced it for the wholesaler to put in stock to replace the one they gave me.

baggs32

New pump

My new NRF-22 is on the way.  It was replaced under warranty by the supplier I bought it from so I'm going with the same model one more time.  Hopefully this will be the last time for a while. 

I've read that draining and refilling a boiler too often can be hard on the internals, is that true?  If so, is there anything simple I can do to limit the effects?  We've lived in this house for nearly 10 years and I know the boiler was never drained in that time until I replaced the pump back in late September.  Some say drain it every year and some say to leave it be.  Who is right?

Charlie from wmass

I would leave it be

The oxygen is removed as the water is heated so it becomes less corrosive to the system as it is cycled through. Test the waters PH to get an idea if it is corrosive from the tap. Additives can be used if it is acidic but should only be used when shown by water test to be needed.

baggs32

Letting it be

Thanks Charlie.  Our tap water is good on the PH.  I tested it for a pool this summer and it was right on target.  I'll be draining and refilling tomorrow.

baggs32

Chattering again

The new B&G circulator has been on for about a month now and it too is beginning to chatter.  I noticed the slight chatter through the rads last night and am now completely disheartened with this unit.  I noticed over the weekend that the pressure in the boiler dropped to around 6 or 7 psi when it completely cooled down (it was warm here in Pittsburgh as you might know if you are an NHL fan).  It ony ran about once a day for 2-3 days so it was completely cooled down.  I let it go and the pressure went back up to a low of about 9 psi and a high of 12 psi during the cycles as it got cold here again.  After I heard the chatter I decided to bleed the rads and increase the pressure to a low of 11-12 psi today but the chatter was still there during the first cycle after that.  It's a very light chatter but it sounds like it's the start of something bad again.



Any ideas anyone?  Could this be yet another failing B&G circulator?  If it is I'm not warrantying this one and will go with a Taco.

Ironman

Cavitation?

Your pump may be cavitating. If it's pumping toward the expansion tank with your boiler pressure that low, you're a good candidate for it. Get your fill valve set to 12 - 15 psi, cold.



The best pump made will cavitate just as quickly as the cheapest under right (wrong) system conditions.

baggs32

Cavitation

I had thought that but I don't really know what would cause it to happen or what other symptoms are.  It pumps away from the expansion tank but I did notice that when the pressure dropped I could hear more water running through the pipes.  Seems like that could cause some cavitation?  Are there any easy and effective ways to reduce or eliminate cavitation?  Short of installing an auto air remover that is.



One other thing, should I leave the fill valve open even if there is no backflow preventer on the fill side?  I currently keep it closed for fear that the dirty water in the system will enter our drinking water supply.  When I installed the first circulator I had to install a new pressure regulator on the fill side because the old one was shot and did not let any fresh water through to the boiler.  I really have no idea whether or not to keep the fill valve open or not all the time.  Other than boiler water getting into the fresh water supply are there any other dangers to leaving the fill valve open all the time like excessive pressure to the boiler?

Ironman

Boiler Pressure

Many factors in a system can cause or contribute to cavitation. Without knowing and seeing everything in your system, it appears your biggest issue is not enough pressure on your system. I'd recommend that you get your boiler pressure up to at least 15psi, cold. This is accomplished by turning the adjustment stem on the fill valve clockwise to increase pressure. Do it slowly with the boiler cold until it settles at 15psi. Too little system pressure can cause cavitation.

Ironman

Fill Valve...

I'd leave it open. I'm referring to the shut off valve before the fill valve, not the manual bypass valve. If you close it, you'd better keep a close eye on the boiler pressure to see if it starts dropping every day.



The only way that the boiler water can back up into the potable lines is if your house looses pressure on the potable lines. A backflow preventer should be installed any time the fill valve is replaced.



If you close the shut off valve and the system continues to loose pressure, you'll dry fire the boiler and be creating a potential bomb. And if you're loosing pressure, you've got a leak(s) that needs repairing. Constantly adding fresh water is not good for your boiler.

baggs32

Fill valve?

I think my problem is that I don't know what you mean by a fill valve.  It is set up like this on my system.  Potable water pipe to shutoff valve to B&G pressure regulator with attached pressure relief unit then another shutoff valve then the pipe that goes directly into the boiler.  Is the fill valve something different or do I have one and I'm calling it the wrong thing?  The pressure regulator/relief unit I have is like the one on page 4 of this document only it is red (made of cast iron) and does not have the quick fill lever.  It is an exact replacement of the one that failed I mentioned above. http://www.bellgossett.com/literature/files/18.pdf



I do watch the pressure regularly and it stays between 10 and 16 psi now.  10 while completely cold now and about 15-16 when the cycles are over and it's hot.  It goes back down to about 11 when cooling during constant cycles because it never really completely cools down due to the cycles being every 2 hours or so.  I think I lost pressure as mentioned above because I bled the rads too often when I put this newest circulator on.



Sorry for being such a novice and thank you again for your time and help Ironman. 

baggs32

Unit update

This is the exact dual-unit I have installed right after the fill line shut-off valve that shuts off the potable water to the boiler.  http://www.patriot-supply.com/products/showitem.cfm/BELL__GOSSETT_110199 



So is this considered a fill valve and should I leave it set at 12 - 15 psi going to the boiler with the shut-off valve open?  I don't know why but leaving that shut-off valve open to the potable water seems dangerous to me.  It never was on before while the series 100 pump was there but I honestly don't know why.

baggs32

Pressure update

I took your advice Ironman and opened the fill shut off valve and adjusted the pressure regulator, immediately after it to the boiler, to 15 psi.  The nex cycle that ran started at 15 psi cold (not 100% cold however) and ended at 21 psi.  Is that pressure too high at the end of the cycle?  The circulator still made the light pinging sound that I've been noticing so it appears the pressure isn't going to fix that but hopefully it doesn't get any worse.  I just need to make it 'til April and then I can take this apart and do it right based on what I've learned over the past couple of months! 

Ironman

Pressure OK

Leave it there and leave the the shut off valve open. Closing it would defeat the purpose of automatic filling. 21psi hot is fine.



 Make sure there's nothing closed or restricting the return line to the boiler.



When you remove the pump, look at the impeller for damage that would indicate cavitation (pitting, worn down, cracks, etc.).