View Full Version : Add a new rad to Combi system.

28-09-2007, 11:43 AM
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....*

|normal rad|

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 :grin:

28-09-2007, 05:03 PM
call a plumber lol!!! otherwise youll need to turn off the water and drain the system. turn the water off at the mains (stopcock) then test by turning on the water to make sure its off. then youll need to empty your water tank by running the hot water in your bath or similar.

below is a rough guide that shows a diff method but you get the idea, the way ive mentioned above is how ive seen it done.

Bathroom Repairs - Changing a Radiator / Heated Towel Rail (To view links or images in this forum your post count must be 1 or greater. You currently have 0 posts. Installing a Towel Warmer | Heating | How-to | This Old House (http://www.thisoldhouse.com/toh/video/0,,1639335,00.html)

07-01-2008, 11:08 PM
all you need to do is turn off the thormostat and the shut of at the other side drain rad down take off put new rad on the same way as you took off you will get a little water on floor

05-02-2008, 06:02 PM
right. you dont need to turn the water off as it is a sealed system on a comi so you have the same water in the system at all times. just turn off the feed valves just under the boiler for the central heating. then drain the system vis he drain valve. (usually loctaed on a downstais rad. then take off te old rad and replace with the towel rail. then refil the system via the filler tap (normally just below the boiler.) bleed all the system( you know how to do this?) then off you go mate. hope this helps. if you want full details email me. i am a gas engineeer

05-02-2008, 09:58 PM
I did it last week. Like the previous posts say, you do not have to drain the system. combi boilers have no water tank. I bought some 15mm chrome pipe , a couple of nice shiny valves and a couple of chrome angled compression joins. I had to do it this way as the pipes were coming from the floor and it was tiled. So i did not fancy lifting the tiles. Make sure you dont over-tighten the valves or compression joins or you will bend the olives inside(i found out the hard way) and you will need to get new olives. I am not a plummer but was well impressed with the results. Give it a go. If all else fails, phone mario.


06-02-2008, 01:20 PM
You shouldn't really join rads in series, they should be paralleled.
So from your drawing above (C) and (D) should remain connected to the boiler and you should "T" off of (C) & (D) to (A) & (B) respectfully.

This is especially true if the rad has thermostats fitted, because if it gets hot enough then the rad will turn off, thus turning your towel rail off too.

Just my 2 pence worth.