Boiler whistle.

ChasMan

I did a couple of upgarades to my system and now I have a whistle inside the boiler that was not there before. It is a 5 zone / 2 pump hot water system (Triple Pass) with zone valves and a Smart 50 Indirect on a third circulator.

I drained the system and replaced my two Grundfoss 3 speed circs with Alpha's and I also replaced the Air vent on my Indirect tank with a Spirovent Eliminator.

After filling and purging, there is normally a little air in the system but no whistle. This time though, there was a groaning and a whistling sound whenever the the burner fired. The groaning has disapeared after about a week but there is a whistle. It starts about 30 seconds after the burner fires and continues after the burner shuts down for about 30 seconds. If I put my ear to the boiler it sounds like running / gurgling water.

Any thoughts? I was going to repurge it thinking there might be an airlock somewhere but that seemed highly unlikely after a few weeks.  I read here somewhere that sometimes pumps can allow air in. And I also read something about chattering check valves causing whistle issues. The sound is definately eminating from withion the boiler. I see no signs of leaks on the outside of the boiler. I haven;t pulled the jacket or even opened the burner door yet though.

The IFC's in both of these pumps chatter quite a bit.

bob_46

Whistle

Try setting the Alphas on constant speed, speed three and see if the whistle goes away.

Ironman

I Would Look...

Inside the fire box to see if there's a leak. Also check the exhaust outside for white smoke while the burner is firing.



If no leaks are found, the boiler may be scaled up.

ChasMan

Hmmmm

Well, didn;t get any time to look at it. I did set the circs on three for a while today. I don;t think it has improved. Perhaps Ill get time to look at it more next weekend.



Thanks,

billtwocase

zone valves?

What kind, and did you run 1 zone at a time to troubleshoot? Sounds like water being forced through a restriction. Maybe something in the zone valve base/seat?  Could also be a  defective shut off that was closed to do the work? Not a wise a&& question, but circ pumping in the right direction? It could be caused by a few different things. Let us know what you find, and happy hunting

Steve Whitbeck

noise

The grumbling and whistle is caused by the boiler "boiling".

You either don't have the flow the boiler needs, or have air where it shouldn't be. The noises are only there when the burner is on.  What is your water pressure??

Are you sure the guage is acurate?

Gurgling is only caused by air.

Chattering check valves is caused by not having enough flow to keep them open.

Alan (California Radiant) Forbes

Flow

Steve says, "You either don't have the flow the boiler needs....."



Primary/secondary piping is essential on a multi-zoned system.  Did you pipe it this way?

ChasMan

Going to open it up tonight.

Ok, lots to look for. The noise is the same regardless of flow or of which zones and how many zones are on. there is a lot of flow through the boiler. I have Caleffi zone valves (5 zones). Before this I had regular 3 speed pumps set on low. With only one pump on there was very little flow and I had no noise. With the Alpha's on auto, I get a lot more flow. The noise started right after the pumps were installed.

The more flow through the check valves, the more noise they make. They are silent on speed one but start to rattle on any speed above that. I suspect that is because the water makes a sharp right turn 4" above the check valves. I was going to replace these with regular swing checks to see if that helps.

It is not plumbed primary secondary. It is regular 2 pipe. Worked fine for 4 years.

ChasMan

Hmmmm

Well, I opened it up, cleaned it out for a bit. No signs of water in there. Lots of red crud this year. Baffles were fairly clean. I drained out about 1 gallon of water. It seemed to quiet down a bit. Perhaps there is too much pressure. The guage reads 19. I still have to buy a guage.

ChasMan

Flow or Air

I agree. It is a hissing / Tea kettle type whistle. Today I purged the system backwards. Some interesting goo came out. There was something that was in 1/4" squares that looked like bits of a vinyl tile. It was white on one side and black on the back. It crumbled up fairly easily in my fingers. I have no idea what it was. It looked like it could be a thick (1/8") thick piece of that black stuff you get inside pipes. But it was VERY flat. Almost like it was manufactured. And it was bright white on one side like it was painted. It wasn't grey like calcium. Other than that, some black flakes, a few things that looked like small hairballs.. nothing major. I then purged it forwards as usual. Fired it up and once again, same exact whistle. No groaning though. I don't think it is a scale issue as I pulled a valve and the insides of the pipe is not white, it just has that even coating of black on the iron pipes and the brass bits are pristeen. The pumps I took out have no signs of any calcification, again, just the black slime.

So, now I think it may just be air. The system is always noisy since I put these pumps in. Waterfalls and whatnot.I spent an hour or so today reading everything on the wall there is to read about Spirovents. Maby mine is mucked up. I'm going to order a repair kit for it. 

I think the pressure guage is accurate but I ordered another Weiss one to check it against. Flow is high. The higher the flow, the more noise the checks make. I put the pumps on three and you can hear the checks chatter and the water velocity noise in the pipe is pronounced.

My expansion tank is too small. Static pressure is 15 but tank is only at 12. I can't get it to sit right. But it has always been like that. Was on my to do list. 

Thanks for the help.

ChasMan

Pumps Up -->

lol.. Yes, the pumps are pumping in the right direction. It does sound like water being forced through a restriction. Sort of that sound you get when you squeeze the water out of a mustard container thats been in the fridge for a while but it is coming from the boiler. Near the back Near the top. Almost near where the supply outlet is. I checked, no white smoke, no signs of water in main fire box. I shut the autofeed off. Its holding pressure. I will take the flue pipe off and see if there are any signs of water in there. Only so much time to muck with it.