Adding a new radiator couple of questions please

[Mark1969]

Hi

I am planning on adding two new radiators to my exsisting system but before i do i'm a little concerned about a couple of this. The boiler i a Vaillant Turbomax Plus 824E.
My first concern is how do i know if the boiler will take the extra radiators? Is there a simple way of working this out? Currently there are 7 radiators on the system, 3 singles and 4 doubles of varying sizes. i want to add two small doubles-but will the boiler cope?
Also - When installing the rads, if i am using bi-directional TRV's does it matter where i take the flows and return's from? I was planning on just taking them from the closet rads to where the new ones will go, is this ok or is there anything else i need to bear in mind?
Lastly, when/if i do the job is there an addiative i should be adding while the system is drained down? and whats the best way of doing this?

Many thanks for Any help in advance

Mark

 

[EliteHeat]

The boiler provides about 24kW to the heating circuit and so will easily be able to handle a few more radiators.

Put the valves on either flow or return.

You should be injecting an inhibitor such as Sentinel X100. You can buy these in tubes which have an injector that uses the radiators air bleed tapping.

 

[Mark1969]

Many thanks

So just to clarify, i can tap into any two pipes and add the radiator as long as i use bi - directional TRV's? it makes no difference what pipes i tap into, even if i tapped into 2 exsisting flows or two exsisting returns?

Thanks again

 

[EliteHeat]

No, you can't do that. You must tee from both flow and return. It doesn't matter though, which bit you put the TRV or the lock shield on.