[an error occurred while processing this directive]
Posted by HeatPro on September 18, 2006 at 13:31:08:
In Reply to: Re: Boiler...shake posted by pete on September 18, 2006 at 11:02:18:
Hose-fill the boiler at the boiler drain valve in stages to 20 psig. If the problem doesn't go away by 20 psig, it isn't helping and just let the pressure go down again. If the problem goes away at one of the steps, then you can set the pressure-reducing screw to the pressure that eliminates the shaking.
The problem is local overheating due to low water flow with some zones closed. This often happens as a boiler limes at the hot-spots from leaving a pressure reducing valve open to feed water to replace that lost in a leak, instead of leaving the pressure-reducing valve closed to be able to see that the sytem is leaking, then fix it. There are other ways to solve the problem, such as a permanent bypass to keep a minimum needed flow.