problems with central heating

[dean1966]

I am currently having problems with my central heating system.It all started with a few radiators had stopped working.I drained down the system and removed all the radiators and flushed them.I also flushed the system out with chemicals.I refill the system and it works ok for a few days but boiler was tripping out and indicated pump fault or air flow fault.Also i was having problems with 3 way diverter valve and i have replaced with a new vavle but is still causing problems.I have also fitted a new pump.I have bled all the radiators and the air vent next to the boiler.I have had a plumber come out to look at it and suggested i fit a air vent on the fed pipe coming out of the boiler.At the moment i have the bypass vavle open but still unable to get any flow arond the boiler and the hot water is going into the fe tank.
I also tried refilling the system from bottom to top as well and fitting a hose to mains water to try and clear any air blockages.

As any one got any ideas what could be wrong and how i can get the system back up and working.

Thanks

 

[Groovejet]

What boiler is it? And how old? is it new system?
Have you got the pumpthe correct way round?

 

[Agile]

You seem to have spent a lot of money and replaced a lot of things.

Everything you have done seems to have either not fixed the problem or made it worse.

Dont you think you would be better getting an experienced heating engineer to repair it properly for you?

Then you could turn your attention to something like DIY brain surgery!

Tony

 

[powell30]

It sounds blocked or airlocked to me.

try shutting down the bypass, and all trv's except one and see if this pushes any air etc out

 

[dean1966]

What boiler is it? And how old? is it new system?
Have you got the pumpthe correct way round?

The boiler is a Alpha cdr18 its about 4yrs old.The system as been in for some time now.I have checked the pump and it is the correct way round.

 

[Andygasman2010]

check all the visible pipework around the pump and cold feed with a magnet, if it's magnetic it's blocked. cut out the blocked pipework

 

[jackecole]

When the pump was changed di you check the pump unions/isolation valves for any furr/scale, as this can reduce the diameter a lot and cause a boiler lockout

 

[Agile]

If you changed the pump by closing the pump valves did you do a bucket test on each valve?

Tony