A friend has told me there are TWO topup valves on his new oil central heating boiler. One engineer said to leave the second one closed all the time unless you're refilling, the other engineer said to leave it open all the time. Closing it prevents the pressure dial from reading correctly. I'm only familiar with gas boilers and have only ever seen one valve. All I can find on google are boilers with a valve at each end of the filling loop, and one is a non-return valve, but I don't think this is what he has as he said it's in a different place. Opinions?
- posted
5 years ago