Hallo
The attached shows our oil tank filter valve after about 12 years in salt laden coastal environment. In the end the shut off lever totally seized and there were oil flow problems and it was a pig to change it for a new one by tilting the whole tank away from the valve when nearly empty. The filter bowl needed hitting with a big hammer in a vice to get freed from the valve body and needless to say the nylon mesh filter was clogged with black slime.
Any advice welcome re how to avoid a repetition - eg is it best to change the tank filter at every boiler service? - bothered about the possibility of oil leaks if we disturb the filter bowl seal, but maybe they usually seal up again okay?