Several Radiators not working

[madrussa]

Hello, this is my first post and I am trying to get some help with our central heating system.

We recently had a chemical flush and new thermo valves added to all radiators and a couple of brand new radiators added. The system worked for around a week but has never worked fully since... we have three downstairs radiators that never work properly... they sometimes get lukewarm but never properly hot like the working radiators. There's also a radiator which gets hot even thou the heating is turned off (connected to hot water?). I had a look in the airing cupboard and noticed there is a section of piping running off before the heating auto valve, is this ok?

the hot water works great.
Tank is immersion heater, switched off all the time.
Boiler is brand new Glow worm.
9 Radiators in total, 3 all on same side of house dont work.
Honeywell room thermostat
Honeywell timer / controller

Please see a diagram of the pipes i can see in the airing cupboard.
View media item 29141
Any help or ideas on getting them working would be great!

 

[HERTS P&D]

What did the plumber say when you called him back to look at the faulty system?

You did say new boiler!

Andy

 

[madrussa]

we didnt ask him back... he wasnt a bad plumber but an idiot none the less and he's not welcome in our home.

The boiler works fine, I think perhaps the pump isnt strong enough... the joins for the radiators look a bit messy. Two radiators coming of the same pipes with bent t-junctions. Some radiators the thermo valve is on the intake, others its on the exit.