heating probs

[steve1209]

hi all,
to start with i had a slight leak from my central heating pump so called a plumber, he came and replaced the pump and the 2 valves, turned every thing back on and away he went, came home house cold no heating, called him back he came out for the next 11 days until i said forget it i'll get someone else, new corgi man came and said the other bloke had put the pump on the wrong way so he changed it round for me turn every thing on and once the rad on the landing got warm he went, 2 hours later still cold house no rads hot apart from one in the landing called him up and he said it was just air in the system and should clear in 3 days, that was two weeks ago so called him up and he said he was too busy just get a plumber and tell him to do full system drain and fill it up and everything would be fine..! plumber came today drained system refilled bled all rads and turned on boiler, the flow pipe was hot but return cold and no rads hot so he turned all rads off apart from the one furthest away from the pump but still nothing, he seems to think that the two port valve or zone valve might be broke, so here goes
1. has anyone ever come across probs like this before

2. does anyone have any ideas

thanks for reading this hope you can all help

 

[ChrisR]

Either
1)The pump and motorised valves are not new - or have failed in record time
2) the system is short of water
3) the system has an awful lot of trapped air
4) the system has a serious sludge problem.
5) something else

1) have a good look at them. Do they look pristine?
2) check the header tank. Drain som ewater and check it refills
3) with pump off, do any rads have air in? Turn pump/system on,run a while, turn off, test again. Any difference?
4) Drain some water. What colour is it? Remove a bad rad and flush in garden. Any different?

Is it microbore by the way? (pipes less than 15mm)

5) bypass valve, plumbing incorrect, something electrical wrong (misconnected) .....


My money's on 4.