Air is the most common problem along with sludge that causes most heating system faults, from radiators not heating up, no hot water and sometimes both. Here is what you need to know.
I now have a plumbing shop If you need plumbing parts here is the link for my Amazon shop. http://www.amazon.co.uk/shop/dereton33
Saved some money on plumbers fees? Use the THANKS button.
Or through Paypal using my site link https://www.dereton33.com/page118.html
Many thanks Al.