evohome ATF600 wall mount cable

[DBMandrake]

It would be far preferable to sink a back-box to house the power supply and to use the old thermostat wiring to provide a mains supply from the wiring centre.

Not for me - plaster over solid brick for interior walls. I don't fancy carving out the space for a backbox from brick...it's hard enough just to drill holes in the brick to mount a shelf

Re-using the original mains wiring for the low voltage DC has worked just fine for me, but it does depend on how long it is and what wire gauge it is. My run is probably about 8 metres.

[gordonb3]

It would be far preferable to sink a back-box to house the power supply and to use the old thermostat wiring to provide a mains supply from the wiring centre.

Wow! NO! That is a sure way to set your home on fire. If you really want to install the ATF600 with the transformer mounted to its back you should replace the original low voltage thermostat wiring with 230V installation wire. The simpler approach is to detach the transformer from the ATF600 and connect the blue/red thermostat wiring to the mounting plate instead: red to red, blue to black. Next connect the transformer to the other end of the wires which will typically sit right next to the boiler and which you obviously already disconnected earlier to install the BDR unit.

With respect to distance as mentioned by DBMandrake I'm not real sure what route/distance this wire travels in my house, but it has to be at least 10 meters and I have no issues whatsoever with this installation.

[DorrisMancer]

Wow! NO! That is a sure way to set your home on fire. If you really want to install the ATF600 with the transformer mounted to its back you should replace the original low voltage thermostat wiring with 230V installation wire.

Sorry, that's nonsense (and I hope that anyone considering this is already aware of cable colour schemes). Wiring to the old-style thermostats is typically 6243Y (flat, 3 core + earth) cable ... maybe you misunderstood what I was suggesting (and have done myself).
The potential (pun intended) problems with having the power supply remote from the device are: safely mounting the PSU and voltage drop on the cable, and I don't know whether anyone has measured the current drawn by the device, the output voltage range of the PSU and the acceptable minimum voltage for the device ... with that info (and knowledge of the cable resistance) it's just ohm's law.

Sinking a back-box into brick is very quick if you stitch-drill with an SDS drill.

[filbert]

Sinking a back-box into brick is very quick if you stitch-drill with an SDS drill.

Depends how hard the bricks are. Some of mine are very hard to drill into. Also, the 'plaster' is more like a cement rendering. No fun.

[gordonb3]

Sorry, that's nonsense (and I hope that anyone considering this is already aware of cable colour schemes). Wiring to the old-style thermostats is typically 6243Y (flat, 3 core + earth) cable ... maybe you misunderstood what I was suggesting (and have done myself).

Not where I live. Thermostats are normally connected using a cable that has two 0.5mm cores or in some cases when installed at some later time (e.g. when replacing gas heaters with central heating) using 4 core norm88 telephone wire.

[Edinburgh2000]

Not where I live. Thermostats are normally connected using a cable that has two 0.5mm cores or in some cases when installed at some later time (e.g. when replacing gas heaters with central heating) using 4 core norm88 telephone wire.

It's an age thing, nothing to do with geography. In the 'old days' all the wiring for central heating systems was at mains voltage. Like DorrisMancer, my thermostats were all wired with three core + earth mains cable (6243Y 1.5mm² cores; red, yellow, blue; later brown, grey, black). That cable is rated to 19 Amps (in conduit) - that's 4kW at mains voltage - far more than would ever be needed for a boiler and pump.

[DBMandrake]

It's an age thing, nothing to do with geography. In the 'old days' all the wiring for central heating systems was at mains voltage. Like DorrisMancer, my thermostats were all wired with three core + earth mains cable (6243Y 1.5mm² cores; red, yellow, blue; later brown, grey, black). That cable is rated to 19 Amps (in conduit) - that's 4kW at mains voltage - far more than would ever be needed for a boiler and pump.

Similar here. The wiring to my original (mechanical!) thermostat that was replaced by the ATF600 is full 1.5mm flat 3 core 240v mains cable - the same stuff that ring circuits are wired with. Mine is old enough to be colour coded red and black...

[DBMandrake]

Depends how hard the bricks are. Some of mine are very hard to drill into. Also, the 'plaster' is more like a cement rendering. No fun.

The bricks in my internal walls are unbelievably hard. If you accidentally drill into the mortar between the bricks they're easy but other than that even a brand new masonary drill bit really struggles, and I've gone through a few of those in the time I've lived here... I still have a set of shelves to go up in my study that have been sitting undone for nearly a year because I can't face the hassle of drilling so many holes into those blasted bricks... I think I'll have to buy a hammer drill first!

No way am I going to try to drill out a full depth back box when I don't have to.

[DorrisMancer]

If you are using masonry drills then it sounds as if you haven't yet experienced the benefits of an SDS drill - they are orders of magnitude more effective than the old style hammer drills that we all used 20+ years ago.
... and now back to heating ;-)

[prozak1982]

After butchering (don’t ask) the power supply, supplied with the ATF800, I bought a replacement 5V 1A power supply off of eBay and cut the end off before connecting the now exposed red wire to + and the black wire to - on the ATF600 which has worked a treat - the power supply is plugged into a mains socket on the wall behind that of the wall mount after I drilled a hole for the cable to feed through. ATF600 wall mount with ATF800 power supply and no 4v transformer in sight. NB. + on the ‘white’ power supply out the box of the ATF800 in my case was in fact the wire with the writing on not that with stripes which I overlooked hence the initial error.