Worcester Bosch 40CDi radiator problem

[bountybar]

My 1 year old combi system is not performing very well, hot water is fine but the heating is not. Since it has been installed I've never really been happy with its performance with no radiator ever getting really getting hot.

However we have had a loft extension put in this last month with a radiator and a towel rail in it, and things have now got much worse. Most of the downstairs radiators do not get up to heat, some get just a little warm others are stone cold. The first floor is better with rads getting warm but not what you would call hot.

I'm getting the run around from my plumber who has suggested the system just needs balancing but I fear there is a more deep seated problem than that for the following reasons..
No one radiator is very hot and if I feel the return pipe at the boiler its cold.
Quite a number of the rads seem to have there valves fitted the wrong way round as the flow is coming through the thermostat first on some and through the lockshield on others.
The boiler seems to just heat the water for a very short period of time (and always has done I think) before shutting off.
I found out today that the system has been running for a year with the filling key inserted, the manual states this should be removed after filling so I have removed it.
The system has been filled to 2 bar which again seems contrary to the manual and to general advice on this forum.

So lots of questions does anyone have the answers.
Has / is the filling key part of the problem?
Should I reduce the pressure to 1 bar?
Is the wrong fitting of the valves something to be concerned about?
What does the cold return pipe indicate?

Or is it really that the 2 new rads in the loft have unbalanced the system and nothing else?

Thanks

Adrian

 

[Bahco]

Reduce the pressure to 1 bar and read HERE for balancing advice.

Come back if you are still having problems.

 

[bountybar]

Thanks

What is the best way to reduce pressure to 1 bar?

 

[clf-gas]

Thanks

What is the best way to reduce pressure to 1 bar?

Reduce pressure via a drain off on one of the lower rads.

how many rads on the system at pressent.
what is the heating temp set at.
was balancing carried out when boiler was commissioned
was balancing carried out after additional rads installed

 

[bountybar]

16 rads on system
Balancing was done but not by anyone with any real skill.
Don't know if balancing was carried out at commissioning.
temp is set to 5 on a scale of 6

Will drop the pressure and post back.

 

[bengasman]

One year old system is under waranty. If not balanced properly, it is even less likely to be flushed properly, which will cost you lots of money in years to come. If your installer has cut corners here and is unwilling to solve problems, it is likely he has cut other corners as well, possibly with safety issues. One thing I have seen more than once is an inadequate connection of the condensate to the waste. This could potentially vent products of combustion into the house. This is rated as – ID –
IMO, a justified case to ask CORGI to check the installation due to safety concerns.
Sounds like a cowboy job to me, usually also no benchmark record, the blue and white A4 sheet with testresults, or when you measure now, the values are nowhere near duplicated which would make it likely the test result was falsified.
Did you get a letter from the council to confirm that your installer has done the notification?
Is the boiler registered with Worcester for waranty?

 

[bountybar]

Pressure now dropped and things working better, more flow through system and can actually feel some warmth in return pipe. Going to have a go at balancing and see what happens.

Will look into paperwork and certificates on Monday.

I take it I should not be concerned about thermostat and lockshield being fitted wrong way round on some rads?

 

[clf-gas]

Pressure now dropped and things working better, more flow through system and can actually feel some warmth in return pipe. Going to have a go at balancing and see what happens.

Will look into paperwork and certificates on Monday.

I take it I should not be concerned about thermostat and lockshield being fitted wrong way round on some rads?

If your having a go yourself BB, then have a look here http://www.diydata.com/projects/centralheating/balancing/radiator_balancing.php

Have a look at the TRVs do they have arrows pointing in boyh dirrections?, if so then it does not matter.