Add a new rad to Combi system.

[nss1888]

hey folks,

I have a combi boiler and want to add a Towel radiator to the system.

the radiators are on the wall as follows:
.*................*
**************
.*................*
**************
.*Towel rad....*
**************
.*................*
(a)................(b)

.-------------
|.............|
|.............|
|normal rad|
|.............|
.-------------
(c)...........(d)

Now currently (c) and (d) are connected to the boiler

But what I want to do, is connect:

(d) to the boiler
(c) to (b)
(a) to the boiler....

What is the best method to do this without flooding the hoose???

any help gratefully received