hi,i am posting this for my farther who hasn't come over to the 21st century recently his boiler has been getting very hot so we stripped the front off to have a look and the pilot light is fine but when you fire up the main burner it seems to be letting out to much gas as the flame is massive and obviously getting through to the outer case of boiler and making it red hot my question is can the flame on the main boiler be turned down to stop this? any help would be much appreciated as said in title boiler is glowworm spacesaver mkII dating back to the stone age.