hot water but no central heating.

[flipper1]

I've got an old coventional c/h system. f/e tank and hot water tank are in the loft. after loosing both hot water and central heating i fitted a new pump. now i have loads of hot water but no/very little central heating. i have back filled the system from a hose, and i dont seem to have any air in the system. Possibly the 3 way valve at the hot water tank is no good but i switched it to manual and still nowt.
Any ideas??

 

[gas4you]

First thought would me a major air lock in the heating cicuit. Have you set just ch, bypass shut, all rads off but one, pump on full to see if it will push it through?

 

[flipper1]

When i brought the property i had to run both hw + ch to get anything. Seems that the f+e tank isnt filling the boiler. Also not sure about the 3 way valve. next step was to take all the rads off and flush through as they are very silted up. I will do this then try your first suggestion.

 

[gas4you]

Open a drain point on the system and look in the f&e in the loft. If it isn't emptying and filling at the same time then your cold fill be be blocked where it tees into the heating 22mm pipe work.

 

[bengasman]

what happens when you rund dhw and ch completely independetly?

 

[flipper1]

yeah i drained the bleed tap on the botton of the boiler and it trickled out. iI fear that it could be the join from the f+e into the 22mm. This is behind my shower unit - oops!
i will also check what happens when i run 1 at a time.
Thanks for all you help guys!

 

[bruce 1411]

i had the same problem water trickling out and after much searching i discovered some twit had closed the gate valves in the airing cupboard