Banging noise.

frankjc

Hi, first post here.
I have an oil fired, forced hot water system, and lately been having some loud banging noise. It seems to be coming from the red BG flo control valve. I have included a picture.
It doesn't happen every time there is a call for heat, but it seems to be getting worse lately. My first thought was maybe air in the pipes, but I can't find bleeders anywhere.

coby

First check to see if enough water in the system. Do not trust the boiler gauge, use external gauge. You can put it on the boiler drain and open to check system pressure. If low maybe part of your issue. Among other things.

frankjc

Ok. Honestly I haven't even looked at the boiler gauge. Where would I find an external gauge?

frankjc

So, I went home on my lunch break, and took a look. It looks like about 17 psi.
I tried turning on one zone at a time, the downstairs zone was nice and quiet. Seemed to work normal. When I turned on the other zone, upstairs zone, the noise happened. Could I possibly have air in one only zone, but not the other? Could it be a circulator pump issue? It is the same zone that I replaced the pump on 4 years ago. I took out my phone to get video, but the noise was gone before I was ready. The noise is rattling inside the BG Flo check. It resonates through the pipes.
When the circulator was not working someone advised me to open one or both (i can't remember) of the valves in this picture, and it basically made the whole house one zone. I wonder if I should try that again.

frankjc

Also also the temperature in the boiler is 170 is that too cold you should be higher than that?
And and thank you all for your responses by the way I really appreciate it