Replacing a radiator - a few questions...

[Dr_Doolittle]

The radiator in my bathroom is quite small, and i'd like to change it for a double rad. First of all, do rads come in standard sizes? The existing one is 745mm wide and 525mm high. Any similar sized rads i've seen are either 600mm or 800mm wide.
The reason i need it the same size is because the pipes are tiled & grouted around, and it would mean lots of extra work if i was to get a longer rad. The distance between the centre of the flow & return pipes is 810mm, if that makes any difference? Also, would the pipes need to be further away from the wall if i managed to find a double rad that fits? Or does anyone have any suggestions on how to overcome this problem?

Last thing - I've attached a pic of my boiler - can someone tell me how i would go about topping up the system if i change the radiator - i've looked in the wiki etc, but i'm not entirely sure how to go about this.

http://i187.photobucket.com/albums/x228/Dr_Doolittle/DSC00454.jpg

Thanks for you time - i know there's alot of questions there, so even an answer to some of them would be appreciated.

 

[gas4you]

I would go for a 700mm long and either a 450mm high or 600mm high, probably the latter. You then need buy 2 20mm rad extensions that will fit between the rad and the valves. If you go for a 'proper' double with 2 sets of fins on it you are most likely to have a problem with the depth off the wall, although the rad brackets supplied have 2 depths for hanging. Choose the shortest one. If you went for say a Stelrad Compact 600 x 700 P+ rad then this will help as it is not so deep off the wall, but will still give a significant increas in output compared to your existing single rad.

To top up your system you will have 2 taps, probably similar to washing machine taps next to each other and possibly a flexible silver hose connecting them. That is your filling loop. Open both taps and re-pressurise to about 1-1.2 bar.

 

[Dr_Doolittle]

thanks for the prompt reply - i couldn't find the filling loop last time i looked - is it always beside/behind the boiler?

 

[gas4you]

Not always. Could be in the airing cupboard, could be under the sink, unfortunately not all installers put them in usual obvious positions.

 

[Dr_Doolittle]

i found this rad online:

(4th one down)

http://www.inspiredheating.co.uk/acatalog/MYSON_PREMIER_HE_DPX_530mm_HIGH_RADIATOR.html

It's roughly the same size as the existing one, but it's a double with single convector. I presume it would be easy enough to swop this for the original, and would the heat output be much greater? or would i be better getting the 640mm high one?

I wonder if i can find one like this in ireland! lol

 

[gas4you]

They will probably supply to Ireland Via the nearest Plumb Center. I often do from my internet shop!

 

[Dr_Doolittle]

thanks for your help. I found a supplier in Ireland who sell the exact rads i linked to above. I think I'll go for a single one 690mm in height - that will mean the pipes should ok where they are.

Now to find that filling loop! I had another look today - no sign of it

I'll have another look at the weekend......