Whistling sound

wavewuver

I have a hot water oil fired system with 3 zones and a single circulator pump. Well over a year ago, I started hearing this whistling sound when one zone (main floor) was calling for heat. The sounds comes and goes at regular intervals of about 20-30 seconds. It sounds like a train whistle in the distance. Over time the noise seems to be getting louder. The noise occurs even if the oil burner is not running. I have tried to isolate the sound but cannot seem to pinpoint the source.



Since it is only happening with one zone, can I rule out the circulator?



Could it be the zone valve?



Or, could there be some sort of flow restriction within the boiler itself.

billtwocase

whistle

piping pics and zone valve, expansion tank type and location also needed. Possible one of your toilets need attention?

wavewuver

A few pics of the piping etc.....

Here are a few pics. The zone that is producing the whistle sound is in the center one of the three. Zone valves and circulator pump are both Taco. Sound is something that has been getting louder over the last year or even two.

billtwocase

I would 1st try

swapping the zone valve head with another zone. I have found some that would partially open, enough to get some heat, but not fully depress the valve seat thus making a restriction noise-whistle, hammer, etc. If that zone still whistles, then the guts-valve/seat assembly is no good. Swapping the power heads is a wire by wire switch, but the water end of the zone valve needs an experienced person to replace. It is also cheaper to buy the complete valve and use the parts-head/guts. If it was a piping issue, or circulator, they would all whistle. I mentioned a faulty toilet. I have found whistling noises traced to them too. Good luck, and keep us posted

billtwocase

also

Is all piping visible? I mean any in a crawl space, or under a slab? If you are losing water somewhere, the 1156 would slowly replenish it and possibly whistle 

wavewuver

Thanks....

Fortunately, all piping is accessible. I don't think I have a leak.



I'll check the zone valve operation soon. There are levers on the valve that permit manual operation. I would assume that if the lever can be easily moved to the open position when the zone is calling for heat means the power head is ok. I think that is the case. Funny thing is you cannot hear the whistle sound at the zone valve. Plus the sound comes and goes in a definite rhythm.

billtwocase

lever

With the zone calling for heat after a couple of mins, the lever should move freely and full to the manual position with no stopping. If it only moves partial, then the head is failing. The head could be opening and closing or the circ is shutting down on low limit causing the breaks in between. It looks like a "V" series Burnham boiler. I would also follow the pipes around and make sure they are not in contact with metal-like a beam or something. It may still be the rubber washer in the valve/seat, but try swapping heads 1st. Make note of wiring before the swap

wavewuver

How to remove the head?

If I recall correctly, after disconnecting the wires, you turn the head 90 degrees, I think.

billtwocase

twist off

Yes, but after the thermostat has been turned down for a few mins. Less than a 1/4 turn clockwise, then it should come. Shut the switch off while doing this.

wavewuver

Swapped the zone valve heads

Very easy task to swap the heads. I carefully marked the wires so they wouldn't get mixed up. Took the zone valve head off the offending zone and swapped it with my basement zone. It may be too early to conclude, but it seems like the noise is gone. If the noise switches to the basement zone, then I will be sure.



Thanks for the tips...........I hope it worked. If not, I'll be back.

billtwocase

good luck

I hope this works for you. Sounds like the head has lost some wax. You're welcome

wavewuver

Mostly fixed

After swapping the power heads I no longer get the rhythmic whistling sound. Now, I only hear that sound right before the zone valve closes. I think what was happening before was the zone valve wasn't staying fully open all the time. In fact it was slightly opening and closing continuously and that caused the rhythmic whistle. What I will do now is get a new power head and leave the rest alone. I can live with the slight whistle sound just as the zone valve itself closes, but I wonder if that means the zone valve itself is slowly failing?