You may have already seen this but just in case ....
http://www.horstmann.co.uk/downloads/ElectronicDocuments/Central-Heating/WiringGuide.pdf
look for ACL-Drayton switchmaster 400 (page 6?)
I'm not an expert yet and i honestly cannot believe my eyes, especially as she is doing some industry approved courses, you would think a newbie would be doing/trying to do everything by the book :?
..wouldnt you :?:
so its worth opening up and checking the boards for any signs of the obvious then.
BTW - we always switch it off at the plug whilst the tv is ON, left it overnight (unplugged-as always) and it has same fault this morning :cry:
the new one doesnt need them as it takes the 240v internally from the LEN connections.
I though i'd ask just in case the ST699 was not wired for 240 this would have meant that you were sending 240 to things that didnt want 240 - get me :?
and if you have defo connected the wires correctly on...
terminal 4 on the switchmaster is HW off in my manual.
I replaced my switchmaster with a C21 (same as C27 but only a 1 day programmer) so you should have no problems.
You might want to know the flow rate as well as the pressure, if its off a combi then a thermo mixer or pressure balancing mixer will be the best bet and if your combi works these will work.
an electric shower is a good idea though as this will give you a means to clean when the combi is 'out...
You are basically restricted by the sinks location by the location of the nearest suitable drain, so if there is not a drain directly outside (or within a couple of meters) then you will have to put a drain nearby.