Can you pls confirm that the Maplin part is a direct repalcement for the original and I should be bale to just replace.
The original relay which came with my RJ2802 relay junction box (aka Satchwell 432-2-802) was a OMRON Type MY4, I could have purchased it from
http://uk.farnell.com/omron-industrial-automation/my4-220-240acs/relay-4pco-220vac/dp/186508. The datasheet for the relay is available from
http://www.farnell.com/datasheets/1514129.pdf.
Instead I went to Maplin as I needed the part right away (it would have taken too long to get the part from Farnell due to the Christmas rush). The guy from the Maplin shop in Glasgow was very knowledgeable with electrics, we compared the N14AW relay with mine and those seem to be exactly the same. Bottom line you need a 14 pins (for plug-in socket), 240V, 5A, 4 PCO (i.e. 4 contacts) relay. My central heating has been working fine since Christmas using a N14AW relay in the RJ2802 relay junction box. To be honest you cannot go wrong for £4.49, and if it does not work you have 30 days to return the product. The risk of damaging the current installation is very low, the 5A fuse should blow away first if any problem.
I'm not sure that Maplin part number is quite correct, they list it as 12volt.
The Maplin web site definitely lists N14AW as 240Vac, and that the one I purchased.