David2452
Well-Known Member
A restriction in the exhaust usually results in a non start acompanied by loads ofwhite smoke rather than a shut down but try it anyway, bubbles apart from a very small amount will affect the running of the heater but without actually seing just how many and how big they are it is impossible for me to comment further, you judge whether you think they are too much, I aim for none. If you have access to a flue gas anayliser it will confirm if the burn is too lean and causing an overheat, as will checking the tempeature in duct outlet of the heater with a probe if you can borrow one. A little white smoke on start up and shut down is not usually a cause for concern, it is simply unburned fuel. Do the values of the reheostat match the correct values too.