Drayton auto balancing trvs

[Mikeyward]

Ive set up my auto balancing trvs, i used the online calculator and got the flow temp from the boiler. them i got the delta t from the flow and return of the pipes from the rads and set them up. but I've got a couple of radiators upstairs that are hardly warming up and the rest of the rads upstairs are not as hot as the ones downstairs has anyone got any idea what I could do, also they are 15mm and I'm using 8mm microbore I've fitted a adaptor would these cause the problem the downstairs rads are hot

 

[Madrab]

Yes. 8mm Microbore can struggle with anything but the smaller size of rads and it needs to be finely balanced to ensure there is enough flow to satisfy every run and rad. Typically that would be a manual setup up but that is typically set for a given point in a system and invariably changes as individual TRV's close down.

The auto-balancing (Drayton?) valves can work with 15mm feeds, from a 22mm backbone on similar pipe run lengths but nothing's ever that straightforward and typically CH systems haven't been laid out as they should. Unfortunately though they won't just work on their own and need finely setup correctly incorporating the other system factors. They also benefit from a modern modulating pump that has been set correctly to achieve the correct ΔT/ΔP but again that will struggle with a 8mm system as the requirements change during operation.

Balancing can be very tricky to get right especially when the system pipework gets smaller.

 

[Mikeyward]

Thank you for the reply so are the drayton auto balancing valves no good then? Could I adjust the settings on the valve abit higher or could I leave them in the commission setting and set the lockshield valves with checking the flow and return pipes

 

[Madrab]

It's not that they aren't any good, it just isn't as straightforward and as easy as they kind of make it out to be. Yes you can always set them higher.

Why were they fitted in the first place, was the system struggling to warm up properly and evenly to start with?

 

[Mikeyward]

It wasn't heating up evenly so I thought I would fit these as they said they are auto balancing would it be best to just adjust the flow abit higher on the valves then

 

[Mikeyward]

Could I adjust then higher until I reach the 11 degrees drop