I have a Vailiant Combi boiler which has had so many parts replaced over the years, it's unreal but that's another story.
It was last serviced in April this year where it had a powerflush, a magntec magnetic filter and all the relevant inhibitors installed. It has been working pretty well up (heating had not been needed) until we had the cold spell where I noticed some of the rads were not working.
I have bled all of the rads (some big air pockets there), and then tried balancing the system. It seems that the radiators at the end of the chain only get hot if I turn all of the radiators downstairs completely off. In one bedroom, it only gets hot if I turn half of the upstairs rads off aswell!! However, once I have the end rads upstairs get really hot, I turn on the downstairs rads (some by only a quarter turn - or less) and then it seems to mess up the upstairs rads.
Onto my question - is this then likely to be the pump (again) or is there anything else I can try? All of the hot water and downstairs rads work fine - get nice and hot but it is very strange on the upstairs rads. In one bedroom they will be boiling and then the next door - not more than 4 metres away will be freezing cold? I would have thought they would at least be slightly warm hence my confusion.
Thanks in advance for any replies.
It was last serviced in April this year where it had a powerflush, a magntec magnetic filter and all the relevant inhibitors installed. It has been working pretty well up (heating had not been needed) until we had the cold spell where I noticed some of the rads were not working.
I have bled all of the rads (some big air pockets there), and then tried balancing the system. It seems that the radiators at the end of the chain only get hot if I turn all of the radiators downstairs completely off. In one bedroom, it only gets hot if I turn half of the upstairs rads off aswell!! However, once I have the end rads upstairs get really hot, I turn on the downstairs rads (some by only a quarter turn - or less) and then it seems to mess up the upstairs rads.
Onto my question - is this then likely to be the pump (again) or is there anything else I can try? All of the hot water and downstairs rads work fine - get nice and hot but it is very strange on the upstairs rads. In one bedroom they will be boiling and then the next door - not more than 4 metres away will be freezing cold? I would have thought they would at least be slightly warm hence my confusion.
Thanks in advance for any replies.