stubborn hammer

MelroseDave

Hi,

First, I have a single pipe system.

So, I've been able to quiet all of the rads in second floor of my house by jacking up all 4 legs and making sure the rad was pitched properly. However, I have one rad - the last in the cycle and the smallest in my house - that, at the very <span style="text-decoration:underline;">end</span> of each cycle hammers 5-10 times about 15 seconds apart -- then quiet again. It really maintains a rhythm.   

I have recently had a new boiler installed, and the plumber tried turning down pilot light (the pressure is slightly below 2psi). This significantly quieted down the rad and hammering, but more than doubled the length of time the heating cycle takes (from about 40 minutes for all rads to be fully heated to over an hour and a half). So, we increased the fire and now the hammering is back to where is was before. I'm, and it appears my plumber, is out of ideas.

We also think the valve is fine because the hammer only occurs at the end of the cycle.

Any thoughts????

Thanks!

Rod

Need pictures.

Hi -  Did it hammer before the new boiler was put in?  Could you post a picture of your new boiler and the piping round it ,especially the Hartford Loop.

- Rod

BobC

water hammer

i think you meant to say he turned the Pressuretrol down to 2PSI. This sounds like a gas boiler, did he turn the gas pressure down?



What was the pressure before that and what is it now when the boiler shuts down?



What kind of main vents do you have down in the cellar? What kind of radiator vents are you using? The new boiler is probably making steam a lot faster than the old one did so the system venting becomes more important.



This link will take you to a general discussion about water hammer -



http://www.heatinghelp.com/article/11/Hot-Tech-Tips/287/Water-Hammer-in-Steam-Heating-Systems



Pictures of the boiler, near boiler piping, mains (and the vents), and of the problem radiator would help.



Bob

MelroseDave

pictures

I'll post pictures on Sunday. Thanks.