Got a Bosch Worcester combi 12 year old boiler on a 8 radiator system. Just replaced the kitchen radiator with a larger one, flushed the system several times but now when running the hot water the boiler is making a rumbling noise. I'm thinking the system needs dosing with Fernox but after looking at the Screwfix site I'm at a loss at choosing the right one. Which one should I go for?
- posted
16 years ago