Noisy circulation pump

Peter_D

Three years ago my baseboard hot water heat boiler was replaced with the new one by the licensed heating contractor. The city inspector would not pass inspection of the installation because my house is about 35 years old, and back in the day some of the poly b was used under the slab in my home heating installation. This promotes oxygen to get in to the heating system, and allows all the steel components to rust. To pass inspection we have to install heat exchanger on the poly b side to isolate boiler. It worked OK for two years. Last year pump on the poly b side (there is two pumps one for boiler loop and one for poly b loop house side) start making rumbling noise. Heating still works OK I'm just afraid if this continues for longer time it will destroy pump or other components. Can someone please help me to fix this problem?
Thank you Regards Peter D
Link to the pump noise sound file: https://www.dropbox.com/s/x9v9jg4vkr4n5i9/Pump Noise.m4a?dl=0

Zman

It sure sounds like it is dry.
There are several things I can't see in your Escher inspired piping.
Do you have a pressure gage on the heating side?
Is there a means of filling the heating side?
An expansion tank?
Is the PB in a slab or in the framing?
Sometimes it is easier to sketch a 3D mess like that in 2D so you can see what it going on.

Ironman

Adding the Spirovent without any means to maintain pressure on the radiation side was a mistake. You can screw a 1/2 ball valve or gas cock onto the vent outlet of the Spirovent and then shut it a day or two after that side is pressurized again.

It probably won't help the damage already done to the stainless circ, but at it would prevent it in the future.

It also appears the the HX is under-sized.

I agree with Z that better pics or a diagram would be helpful.

Gordy

Is the circ in the pic the highest point in the system?

Agree with others comments.

Peter_D

No, this is two level home. Boiler is located on the first floor and the pump is pushing water about 14' up to the second floor.
Thanks for replay.

Peter_D

Thank you guys for all the comments it helps a lot to find right guy to fix it.

Tinman

I had to do a google search on Escher.

Gordy

Stephen Minnich said:

I had to do a google search on Escher.

Me too Stephen.

Gordy

What psi is the boiler gauge reading? Is there another psi gauge on the other side of the HX?

hot_rod

with a large screwdriver you can loosen that end screw in the Grundfos pump, air may come out first, then water should drip out.

If not the system may be low or out of pressure on that side.

Both sides should have an air purger, expansion tank, and ideally a fill valve to maintain pressure. gauges for pressure and temperature, and some purge points are also handy.

Peter_D

Thank you for the posts, looks like I have everything under control for now I did everything that you guys suggested, plus i had almost new Grundfos circulator from old boiler so I have swap cartridges from regular circulator to stainless casing of the existing pump (I hope this is ok). Bleed the system and runned for .5 hr no more noise-silence is golden. My hydronic system with heat exchanger was never flushed after initial flushing @ time of the boiler replacement. There is lots of magnetic debris-rust any suggestions ?
Thank you guys for all the knowledge and help.
Ps: There is two pressure/ temperature gauges, one for boiler loop and one for heating side. Both read about 20 PSI Hot Thanks

kcopp

Cleaning the system w a good cleaner and then flushing and adding a good inhibitor is a good start. I like Fernox but there are others.
This is especially is a system w/ non barrier tubing in it.
In my opinion you probably could have gotten away w/o using the HX if you had cleaned the system and yearly kept up on a maintenance schedule w/ the water treatment.

Dave H_2

Peter,

"circulator from old boiler so I have swap cartridges from regular circulator to stainless casing of the existing pump (I hope this is ok). "

This will work for today, but the construction of the older cast iron circulator inserted into the stainless circ will probably cause the cartridge to fail prematurely since this will be the only ferrous component in the system. Even though identical in looks and performance, the bearings are different as is the rotor (stainless steel sleeve)

Your problem is/was contaminants in the bearing assembly as the likely culprit.

Peter_D

Thank you for the post, what I did is only temporary fix, I'm talking with one service pro guy to come and do the maintenance on the boiler I live in Vancouver B.C it is relay hard to find good honest tradesmen, some charge $200 for first hour
Thank again.

hot_rod

The cartridge should be stainless, ceramic bearing, probably a plastic impeller? On both

Unless something inside the cartridge changes on non ferrous circs