Hi.
I’ve just changed out a backup immersion heater on a copper vented cylinder.
I’ve leak tested around all the connections to the cylinder using blue paper towel which tends to stain orange with moisture.
After 24-48hrs of use not a trace of moisture.
However after a week or two I’ve noticed one or two very small spots/stains on the paper towel around the immersion heater and the coil inlet. The towel is bone-dry though.
Any ideas? Is this just condensation or could it be a bigger problem? I’m thinking I might need to replace the tank. I’m not sure how old it is. Tank is in the airing cupboard.
Cheers
