balancing rads - flow rate - banging boiler/pipes

Ok, I have been around the house and balanced the rads with an IR thermometer so that there is roughly a 12C drop across each. However, once approximately every 24-36 hours the boiler and pipes around the house start make a horrendous banging noise, forcing me to turn off the heating for a period. I have read in a separate post this could be do to do with reduced flow rate to the boiler - but why would it only bang intermittently? Could it be an airlock instead? The banging does seem to coincide with my balancing though. Any help greatly appreciated.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have you got TRVs on all rads? If so, they may be closing off, and with no by-pass, will bang-a-go-go.
Angus
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Fentoozler Wrote:

an easy way to try is to remove the thermostat head from any one of th rad valves. that way the rad will not close down and give you a bypass if the noise stops that proves the problem. auto bypass valves shoul be fitted to all new installations see honeywell controls web site the sell one. gaz
-- plumber gaz
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
No TRV's guys just standard LSVs and control valves. I've opened up all the LSV's to increase flow rate, no banging so far, but lots of gurgling around the system - does add weight to air in system hypothesis?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.