Went to clean the fins inside my boiler today and pulled this nasty stuff out of one of them. Only one fin has it. Originally thought it could be tar, but given I'm burning anthracite, I don't believe that to be the case now.
Not sure what it is, or whether anyone has any advice on what it could be.
A bit of (possibly) relevant information. The boiler was off from the 19th of December, until the 4th of January, as we were away. The chimney is open topped, but I'm unsure whether it would be water coming down the chimney, as I imagine I'd see it in multiple of them.
Any help is hugely appreciated
Not sure what it is, or whether anyone has any advice on what it could be.
A bit of (possibly) relevant information. The boiler was off from the 19th of December, until the 4th of January, as we were away. The chimney is open topped, but I'm unsure whether it would be water coming down the chimney, as I imagine I'd see it in multiple of them.
Any help is hugely appreciated
