Have a question about boilers for homes

Does anyone on here have a boiler for heat in their house? Ours has started whistling and we and the people servicing it can't seem to figure out why. They've ruled out the chimney stack, and damn near everything in the boiler But its still doing it. Just started doing it this year. Just curious.

He removed the chimney stack when it was making the noise and that didn't fix it. He did a thourough clean and check. Cleaned all the burners and jets. Cleaned the metal stacks inside the block. The boiler is working fine, heating the house like it always has, except making this noise. Sometimes it's so loud it wakes us up at night. I notice that as soon as the thermostat shuts off the noise goes away within 1-2 seconds.

any ideas?

 

We don't have boilers down here on houses but as water heating only. I'm sure someone with more experience will chime in,but if ya say its been checked out. I'd look around fan and one thing I always do is read gas pressure with nanometer. Don't know what ya have as fuel though.

 

Is there more than one zone ???

 

If there is more that one zone , sometimes you can get a whistling noise if a zone valve doesn't completely close

 

There's two zones I guess. The main floor and the basement. Basement hardly ever gets used. But I guess I should check that.
well, I guess it's two zones. We have two circulating pumps and two thermostats, one for the main floor, the other for the basement (which only has two radiators). So the basement thermostat is off most of the time. The noise happens whether both zones/pumps are running or just one or the other are running.

 

x2

I dont think the boiler is the problem. Can you manually open and close the zone valves? What's your system pressure? Should be 12-20 at operating temp.

I would also say bleed your system...

 

FHW or FHA? (Baseboard heat or air)

Gas or oil fired?

 

Is your heating valve a modulating valve? In other words, it has infinite position between fully open and fully closed.

Based on your observation above, it is a valve issue. Your valve is not closing fully thus allowing flow through at designed pump pressure. You could try knocking on the valve with a pipe wrench when it happens again. If it goes away, you should repack the valve and install a new valve seat as well.

Keep in mind that heating valves are "Normally Open" valves. They modulate and/or close when the system is running to bring the loop up to operating temperature quickly, just like in your truck/car. When your thermostat shuts off, the valve returns to the "Normally Open" position and the noise goes away.

Its hard to make guesses without being there but this is my 2 cents. A zone valve that should be closed is not fully "seating" in the closed position.

 

Baseboard heated water

Gas fired.

 

Where are the zone valves located?

 

Do you have cirulator pumps or valves??

Circulator pumps don't whistle or 'close'.

 

Hard to say. You need to trace your loop or check your drawings if you have them. Most likely, they'll be centrally located in and around the boiler where the piping originates and then splits into separate zones.

 

I have circulator pumps. one for each "zone" i'll take a couple pics and post them.

 

Do you have motors (pumps) attached to your piping at the boiler return??

 

If you have manual isolation valves (every system should), make sure both your automatic zones valves are closed (one at a time) when the system is running and when you hear the whistling noise, manually shut off one zone (by isolation valve) to see if the noise goes away. Open it back up and try the other one. This should narrow it down to the loop/zone valve problem.

You might trip the flow switch based on how its wired or if you close both valves at the same time. But its no biggie as when flow is detected, your furnace should resume the start sequence again.

 

Yeah, need some pics.

Fresh air intake or power vent could make noise too.... if you have that equipment.

 

So here's some pics.

The large metal pipe coming out of the top of the boiler goes to the chimney. just above the top of the pic is an automatic flue. It's electric and opens when the boiler is on and closed when it's not. That's not part of the problem cause the boiler guy pulled the chimney stack completely off and it still made the noise.


Here's the circulator pumps. The left one is the one for the downstairs and the top one is for the upstairs.


I have no idea what this is, but it says taco air scoop on it. Must be something from the TRD sport version of the boiler that was on here previously. lol. Actually, this part was used in the previous setup, and in the current one too.

As far as I know, all the pipes and whatnot were all used in the previous setup. Also, it doesn't make the noise when only the water heater is on, just the boiler for the house heat.

 

SKEWPZ

 

Those are fake. Quite a few threads on it already.

Have your heating guy install a real one.

 

I'd check the auto-fill to the boiler to see if it gets water and the pressure in the expansion tank... the schreader (sp?) valves can leak out the air. The charge pressure should be close to the water pressure of the house.