Removed hose from bottle to refil and noticed gas emitting from the POL fitting. Noticed a cream coloured gunk and removed hose completely. When I blew in both direction it was very restricted , so I used contact cleaner and it cleaned it all up. Now find there is a check valve in the POL fitting to prevent loss when swapping bottle. Will shorten light up times or purging the air out of the lines. 

Hope this helps,

Graham.

NB, Wonder if same could be done to regulator to prevent that stuff blocking it. What is the gunk, probably a product of the gas.

The gunk is the carry oil used to carry the gas during the extraction process, usually it isn't a problem as it is the same consistency as the liquid gas  buy sometimes if the system hasn't been in constant use some of it will settle out...

The safety valve you speak of is called an Excess Flow Valve and is there to stop the flow of gas should your hose burst or one of your gas lines rupture.

Thank you, appreciate the reply, good travels.

Graham and Pat.

I found the same stuff in my hoses, took ages to get anything to light. I mounted the regulator a couple of inches higher so that the gunk would drain back into the bottle and seems to have fixed the problem